System and method for predicting the location of the jamming or spoofing of geolocation information using vessel tracking signals, using trajectory and speed interpolation and data weighting

Abstract

A system and method are described for identifying the location of jamming or spoofing of information that is used in a Global Navigation Satellite System (GNSS) geolocation system, in areas in which it is difficult or impractical to install detection devices. The system and method make use of existing vessel-tracking technologies, such as Automatic Dependent Surveillance– Broadcast (ADS-B) – for aircraft vessels – and Automatic Identification System (AIS) – for naval vessels, to collect data on the speed and trajectory of large numbers of vessels and to use that data to extrapolate areas in which spoofing or jamming may be occurring. The system and method include techniques for sampling tracking data over periods of time in order to establish when data is sufficiently anomalous to indicate the potential for spoofing or jamming to be occurring for a particular tracked vessel. The overall system and method also includes a weighting protocol for data from multiple vessels to predict areas in which spoofing or jamming may be occurring by assigning anomalous vessel signals that are geographically nearby to values as to their potential to indicate spoofing or jamming, and thus calculating an area around those vessels as potentially subject to spoofing or jamming. A processing hub or multiple processing hubs include facilities to compare location information received by a group of vessels with anomalous signals and to determine whether the location information for those vessels is consistent with predicted location information for those vessels. In the event that there is a discrepancy between the predicted location information and the received location information, the processing hub or hubs can take a number of remediative actions, such as assigning the calculated area as one that has been identified as being subject to spoofing or jamming, and sending a warning signal to vessels in that calculated area that their GNSS location information may not be reliable. The system and method of the present invention can also alert affected vessels of the need to switch to a backup or alternative geolocation or navigation system, when it is determined that the GNSS geolocation system is determined to be inaccurate or unavailable in an area in which the vessels are currently located. Artificial Intelligence (AI) or Machine Learning (ML) can be used to better predict and correlate data so the most accurate approximation of where spoofing or jamming is occurs may be identified and subscribers to the system may be alerted.

Description

[0001] SYSTEM AND METHOD FOR PREDICTING THE LOCATION OF THE JAMMING OR SPOOFING OF GEOLOCATION INFORMATION USING VESSEL TRACKING SIGNALS, USING TRAJECTORY AND SPEED INTERPOLATION AND DATA WEIGHTING

[0002] BACKGROUND OF THE INVENTION

[0003] FIELD OF THE INVENTION

[0004] The present disclosure relates to the field of Global Navigation Satellite Systems (GNSS) such as Global Positioning System (GPS), and techniques to address efforts to disrupt those signals using misleading ("spoofed") or altered ("jammed") signals, by predicting via vessel tracking signals areas where such disruptions may be occurring.

[0005] DESCRIPTION OF RELATED ART

[0006] GNSS is a general nomenclature for several different systems used in geolocation, which were initially developed for military use, but have now found their way in many civilian applications. GNSS relies on signals transmitted from orbiting satellites which a receiver receives, and uses to trilaterate (or otherwise mathematically determine) the specific location of a user of the GNSS, based on information extracted from the satellite signals.

[0007] The ubiquity of the use of GNSS systems in mobile phones, watches, car, aircraft, and maritime navigation systems and many other devices where relatively precise location information is needed has led to the efforts to create false signals which attempt to inaccurately replicate (or "spoof") true signals from a GNSS to give a receiving device incorrect location information, or alternatively to jam or otherwise impede - whether intentionally or not - true GNSS signals in order to prevent a receiving device from accurately determining its location.

[0008] Spoofing has been used as a technique to facilitate piracy or other illegal activities around commercial maritime vessels, by driving those vessels off course using spoofed GNSS signals. The result is that the vessel's GNSS system makes use of incorrect location information, causing it to steer into an area away from its desired navigational course, allowing it to founder or to be steered to a location where piracy activities are easier to commit without interdiction. This problem has become particularly prevalent in the East China, Black and Baltic seas, as well as the Strait of Hormuz.

[0009] A jammer is a simple device that injects ("blasts") noise onto a particular radio frequency, which frequency is used by, or adjacent to, those frequencies used by a GNSS system. As a result, the user attempting to monitor its own location using GNSS signals is prevented from extracting the individual satellite signals and their resulting data used for location calculations. The user thus may have to rely upon other, less accurate, navigational techniques and as a result may steer into areas that are dangerous or which may subject them to illegal actions.

[0010] A relatively inexpensive set of equipment, a "spoofer," can be programmed to send out radio signals that are nearly identical to the GNSS signals upon which the on-board navigation system relies; the spoofed signals deviate from the actual GNSS signals just enough to misdirect the vessel to an undesired course, without the navigation system understanding that false signals are resulting in false navigational calculations. Because GNSS signals from GNSS satellites are of relatively low power, a spoofer (or a jammer) does not need to be of relatively high-power output to disrupt a GNSS-based navigational system.

[0011] Spoofing can be more insidious than jamming in GNSS navigational systems because in the case of jamming, the user knows the signal is bad or cannot be received, and therefore the navigational system will simply be incapable of making location calculations - thereby allowing the user to turn to less accurate backup systems for navigation. In the case of spoofing, the user can be misled and misdirected along an incorrect course because the location and navigation system operates as if the spoofed signal is a correct signal and may not have the capacity to alert a captain, pilot or navigator that the vessel is being misdirected.

[0012] GNSS systems make it possible for users of that system to extract and calculate Position, Navigation and Timing (PNT) information. This information can be used both for surveying, as well as for navigating maritime vessels and aircraft, as well as cars, trucks and buses. GNSS systems also have become useful in synchronizing networks, including financial services, stock exchanges, and wireless (cellular) telecommunication systems. All these users can be adversely affected by spoofing or jamming of the GNSS signals. The problem is most prevalent with certain implementations of a GNSS system - such as the GPS system used in the United States - in that L1C / A (Legacy Band L1, Coarse Acquisition) is the most widely used signal. However, as there are multiple GNSS systems in place worldwide, different constellations use different signals, and satellite constellation may use multiple signals in multiple bands.

[0013] The L1 legacy signal band is centred on the 1575.42 MHz radio frequency. The public (or open) GPS signal in the L1 band uses the C / A code, which has been substantially unchanged since 1980. The coarse acquisition (C / A) code is the signal made available to the public, in contrast to the precision (P) code which is only available to military users. Both L1C / A and the military precision P code use BPSK modulation. The newest GPS III satellites add a more modern signal called Lie, also centred on 1575.42 MHz as is L1C / A. The "c" in Lie designates that it is a "civilian" signal. It uses time-multiplexed binary offset carrier (TMBOC) modulation. TMBOC has advantages over BPSK such as better multipath and other interference mitigation.

[0014] As these signals are Code-Division, Multiple Access (CDMA), and power is carefully managed with CDMA technology, they can co-exist in the same band; a receiver of a satellite signal uses the Pseudo Random Noise (PRN) code to decode the signal from a particular satellite. Having all satellites broadcasting on a single frequency has advantages for receiver design, but also makes it easier to implement a jammer as just that one frequency needs to be blocked.

[0015] The issue of spoofing or jamming is not limited to the NAVSTAR GPS system which is used in North America; it can happen with other GNSS constellations and signals, such as China's BeiDou, Russia's GLONASS, and Europe's Galileo. Other regional systems like Japan's QZSS and India's NavIC (aka IRNSS) are theoretically vulnerable as well. Although encrypted and / or authenticated signals such as the GPS military signal M1 in North America and the Galileo OSNMA signal in Europe are much less vulnerable to spoofing, these signals are not generally available to civilian users, who are the vast bulk of current users of GNSS navigation and location services.

[0016] Interference with GNSS signals can occur because GNSS signals, which are inherently low- powered, become overpowered by other signals on the same or adjacent frequencies. This can happen when a GNSS receiver is near other electronic devices designed to overwhelm

[0017] GNSS signals (such as drones or stationary transmitters), or other devices that unintentionally interfere with GNSS signals, such as radio transmitting antennas or modems. Such interference can reduce positioning accuracy by "disabling" signals from satellites needed for trilateration, or causing the receiver to lose positional information altogether.

[0018] Spoofing is the intentional sending of incorrect or misleading GNSS signals to a receiver, so that the receiver reports incorrect location information. Such spoofing devices can be used to hijack autonomous vehicles by misdirecting their route programming, or to misdirect aircraft or maritime vessels to send them on alternate routes. As an example, in 2017, several ships in the Black Sea had their GPS receiver reporting a position at a faraway airport as the result of a spoofing attack.

[0019] There have been various efforts made in the past to provide alternate and complementary methods of detection and mitigation of GNSS spoofing and jamming, such as:

[0020] • Building an advanced interference monitoring and mitigation (AIM) system into the receiver. AIM is designed to detect and neutralize interference with geolocation signals, protecting against simple narrow-band interference as well as more complex wide-band interference, including both jamming and spoofing. Some AIM systems analyze interference using spectral analysis, allowing determination of the type and possible source of the interference. An AIM system is designed to try to detect signals that may be false, or to filter out signals intended to jam true signals. AIM systems generally must be built into new receivers, although in some cases older receivers may be retrofitted to include an AIM system through firmware or other software- based updates to that receiver. A downside to AIM systems is that they require significant signal processing resources within the user's navigational system receiver to implement them effectively, and these signal processing resources are often more than many consumer devices or civilian navigational systems can accommodate.

[0021] Because GNSS has become an integral part of many hundreds of millions of consumer devices, allowing low-navigation or positional information, AIM systems are not a technically feasible solution for spoofing or jamming for the receivers in those devices. • Building more resilient signals with greater signal integrity within GNSS satellites, so that at least false, spoofed, signals may be detected and ignored by the position calculation algorithms in the receiver. The Galileo OSNMA (Open Service Navigation Message Authentication) system used in European Union geolocation services is one such a system for providing greater signal integrity from the signal source satellites. However, building signal integrity within the satellite signal can require many years to design, requires the building and launching of new satellites with improved signal integrity, and may require that the receivers all include specialized improvements and signal processing features in order to process the enhanced satellite signals. By way of example, the newest iteration of GPS, "GPS III," only has four currently launched and in-service satellites with enhanced signal capacity, but a minimum of 24 satellites are needed to be launched into space in order for that system to provide effective coverage and for all users to be able to access enhanced GPS III signals with anti- spoofing and anti-jamming signal integrity.

[0022] • Jamming detection from space has been demonstrated using a GNSS receiver on- board the International Space Station (ISS). However, a full low-earth orbit (LEO) constellation of potentially hundreds of satellites would be required for real-time global coverage of jamming detection, such as by implementing jamming detection in the Iridium constellation, which has 66 active and 9 spare satellites in space. A space- based solution is thus potentially cost-prohibitive and would take many years to implement by launching new satellites with sensitive GNSS receivers.

[0023] • Combining inertial measurement units (IMUs) with GNSS receivers, so as to allow the receiving device to detect differences between movement reported by the IMU and movement calculated by the GNSS receiver, such that significant discrepancies can be flagged to alter to possible spoofing. The incorporation of an IMU into a receiver results in significant increases in power, cost and complexity in the receiving unit, and is dependent on the accuracy of the IMU and measurable discrepancies between the IMU measured distances and distances detected by the spoofed GNSS signals.

[0024] Controlled reception pattern antennas (CRPA) are in use in military environments relying upon GNSS systems. This system uses large antennas designed to be able to detect direction information about incoming signals, and to rely only on those signals for which direction is known to be satellite-based. These antennas can be bulky, complex and expensive, and some of the technology is restricted to only military use.

[0025] At present, instances of GNSS spoofing and jamming are published in, among other locations, the Notice to Airmen (NOTAM) and US Coast Guard Navigation Center (NAVCEN) Notice Advisory to Navstar Users (NANUs) and GPS reports. Due to the dynamic nature of entities or persons attempting to spoof or jam signals, and the ability of those entities or persons to vary the location, signal features, or areas covered by their efforts to disrupt true location signals, these alerts are often out-of-date and don't provide an effective way to mitigate the effects of spoofing or jamming.

[0026] At least one system - Harmonious Rook https: / / insidegnss.com / dod-in-search-of-gnss- spoofing-counters-under-harmonious-rook-rubric / - has been described which is intended to make use of a variety of non-GNSS data as a mechanism to buttress GNSS data. The public details of this program are limited and it is not known if any effective implementation of the concept has been arrived at.

[0027] BRIEF SUMMARY OF THE INVENTION

[0028] The present invention includes both a system, and a method, for determining if GNSS location information within a remote location is subject to potential compromise, by making use of existing location signal information provided by groups of navigating vessels already located within the remote location, extracting data, and using that data to predict whether a GNSS signal in that location may be compromised. The system thus allows for regions around the globe to be identified as subject to GNSS signal compromise - such as, for example, via jamming, or spoofing, or any other natural or human-caused phenomenon which might result in compromised signals - and to report such areas to vessels subscribing to the system that are either already navigating through those regions or wishing to navigate through those regions to use other forms of navigation beyond GNSS signals, or alternatively to avoid those regions if GNSS navigation is going to be continued to be used.

[0029] A global processing hub or regional or local processing hubs which are able to receive and process non-GNSS navigational signals used by vessels around the globe is designed to receive those navigational signals, extrapolate information about whether those signals are consistent with or inconsitent with projected navigational information about those vessels, correlate that information with all vessels within a particular location, and using various weighting algorithms and other techniques for extrapolating trends from large datasets, identify locations which are likely subject to GNSS signal compromise. The system and method can thus, on a local, regional, or global scale, identify where spoofing, jamming, or other interference in GNSS signals is occurring, put out alerts to vessels in those locations, and compile information on where interference may be originating and suggest mitigation or disruptions may be directed.

[0030] In one embodiment of the present invention, the system and method uses information from existing Automatic Dependent Surveillance-Broadcast (ADS-B) - for aircraft vessels - and Automatic Identification System (AIS) - for naval vessels - to interpolate location information for vessels in a particular area of interest, compare that interpolated location information against GNSS signal data for the same location, and via weighting algorithms, assign degrees of risks of jamming, spoofing or other intereference of GNSS signals within regions around the globe. Both ADS-B and AIS track the last known locations of aircraft and maritime vessels, respectively. Although these location tracking technologies are not currently being used in order to determine whether GNSS signals are being jammed or spoofed or otherwise have lost integrity, the present invention uses those systems to serve as indicators of jamming and spoofing, by calculating when vessels using those technologies 'lose position,' or suddenly show up elsewhere, or elsewhen ,than anticipated.

[0031] In the system and method of the present invention, ADS-B and / or AIS data feeds are received as inputs into a processing hub or processing hubs, which uses information from those data feeds to detect anomalous location data, correlate that anomalous location data with other data from vessels in a similar area, apply interpolative and weighting calcluations to the data feeds, and as a result detect areas or locations which may be subject to jamming or spoofing of GNSS signals. For any such areas, vessels which subscribe to the system of the present invention and which need to be alerted that they are in an area of jamming or spoofing can be identifed and alerted. Each vessel using the ADS-B or AIS systems has a unique identifier which it broadcasts along with its position and navigation status, so nearby vessels can navigate safely and avoid collisions. The ADS-B and AIS systems also use terrestrial and space-based receiver networks which monitor and aggregate this position and navigation status data, and in some cases those receiver networks make the data available to interested parties, other than to nearby vessels receiving the data for collision avoidance. As an example, the website GPSJAM (https: / / gpsjam.org) collects ADS-B data from aircraft to show various zones around the globe where the ADS-B signals for that zone are reporting GPS inaccuracies. Although the site calls itself "GPS Jam" it acknowledges that it is not a jamming detection system, just a system that reports out self-reported inaccuracies from vessels in a particular zone that are above certain accuracy thresholds. Whether that is indicative of jamming or spoofing is not a function of the data compilation on that website. Another example are the websites Marine Traffic (https: / / www.marinetraffic.com), a site that uses AIS to track and display maritime vessel navigation information, and the system offered by Orbcomm

[0032] (https: / / www.orbcomm.com / en / solutions / maritime / ais-data) which also provides AIS data as a service. These systems are directed to overall vessel navigation information, sometimes on a global scale, but do not attempt to determine to what extent there may be discrepancies - intentionally created or otherwise - in that navigation data.

[0033] As part of the system and method of the present invention, a database of aircraft and maritime vessels is maintained, and that database is constantly and continuously updated when new vessel position, velocity and navigation status data become available, based on the inputs from ADS-B and AIS systems. Although the ADS-B and AIS systems are exemplary examples of position, velocity and navigation status data inputs into the system and method of the present invention, other current, or future, non-GNSS systems for collection of navigational information about moving vessels of any type may also be used as inputs.

[0034] In the system and method of the present invention, when a vessel's navigation data changes more than an expected threshold, then an exception is raised as to that vessel. A single exception may be treated as a tempoary anomaly, such as the result of temporary signal degradation or of noise. However, additional navigation data for that vessel which continues to be identified as an exception may be used to indicate that GNSS signals for the area through which that vessel is navigating could be compromised. Additionally, if multiple vessels in the same vicinity report similar exceptions at the same time, this indicates a high probability of interference of the GNSS signals in that vicinity.

[0035] The system and method of the present invention is computationally and data-traffic intensive. At present adoption rates of the ADS-B and AIS navigation systems, the system and method of the present invention is designed to track about 10,000 aircraft and 550,000 maritime vessels worldwide. Not every one of these vessels are in motion at any one time, as aircraft may be on the ground and maritime vessels in port or in dry dock. Neverthelss, at any point in time, some significant percentage of these vessels are in motion somewhere around the world.

[0036] In the system and method of the present invention, not every vessel that is in-motion and has a operational navigation system like ADS-B or AIS may have data collected; the system and method of the present invention may monitor only a subset of these vessels - for example, those that are navigating through locations where there is a high confidence that GNSS signals are not subject to potential interference, and thus any anomalous location data has a higher likelihood of being the result of temporary, natural, phenomena, may not be monitored. In addition, the system and method of the present invention may not even choose to collect data from all vessels in a particular location even when that location could be the subject of intentional interference with GNSS signals. As an example, the People's Republic of China alone has about 200,000 fishing vessels - nearly half of all maritime vessels that could be subject to monitoring using the system and method of the present invention. However, many of those 200,000 vessel work in the same vicinity, and monitoring all vessels in the same vicinity may be duplicative of the information which the system and method of the present invention needs to detect unnatural GNSS signal interference. In the case where there may be an excess of location data for a particular area, the system and method of the present invention uses statistical methods to sample from that dataset and still achieve the desired results without having to process excess data which does not add to the overall accuracy of the output.

[0037] In the system and method of the present invention, a database is maintained of all vessels across the globe that have navigation systems which are capable of being monitored - whether they be ADS-B, AIS, or any other existing or future navigation system which sends out signals that may be received so as to determine the location that that navigation system is reporting for the vessel which uses the navigation system. All navigation data from these navigation systems from all vessels globally is fed into the system and method of the present invention. The database, in order to more efficiently extract location data and determine the extent to which GNSS signals are subject to interference, will designate some vessel data as 'inactive' - for vessels that are known not to be actively moving - or assume that certain vessels should generally be considered to be receiving accurate GNSS signals - for vessels moving through regions where there is a high degree of confidence that the GNSS signals in those regions are accurate. The navigation data from the remaining vessels will be considered within the database to be 'active.' In order to make efficent use of processing resources in the processing hub or hubs of the system and method of the present invention, the database of all vessels gets updated navigational data on a periodicity that is longer than the updating periodicity of the subdatabase of all 'active' vessels - for example, the 'all' database gets updated once an hour, whereas the 'active' subdatabase gets updated every 10 seconds, with vessels moving from the 'all' database to the 'active' subdatabase as variations in their location data are detected to meet a criteria set to identify 'active' vessels. Similarly, vessels in the 'active' database can be moved to the 'all' database when they have moved to a location designated to be a location of inactivity (for example, a harbor or an airport), or a location for which active monitoring is determined to not be desirable or useful (for example, a location known to be relatively safe from potential GNSS signal interference).

[0038] In the system and method of the present invention, each vessel in the 'active' database will have an an expected next position based on its location, velocity, and other parameters sent from the non-GNSS navigational system on-board the vessel. If a vessel's GNSS next position report is anomalous from the expected next position on that vessel, then the system and method of the present invention flags that vessel as potentially subject to GNSS signal interference, but does not initially designate the location of that particular vessel as being the subject of GNSS signal interference. Thereafter, for that flagged vessel, if the anomalies are consistent and / or there are other vessels in the vicinity of that flagged vessel are also exhibiting similar location anomalies, then the system and method of the present invention will presume that interference is present in and around the flagged vessel.

[0039] In the system and method of the present invention, all the vessel data, location expected, and actual vessel position information based on non-GNSS data terrestrial networks, GNSS data for the same vessels, individual flags for all vessels, and correlations between vessels in the vicinity of other vessels is coupled together to form a comprehensive picture of locations around the globe where pattern of anomalous GNSS vessel location data is being reported. The system and method of the present invention uses that comprehensive data to calculate probabilities about the extent to which certain locations around the globe are highly likely to be subject to GNSS signal interference of some sort, to create an incident database concerning those locations, and issuing alerts to subscribers to the system and method of the present invention, so that they may be alerted that they are about to enter, or are indeed within, a location where GNSS navigation data should not be relied upon as a result of GNSS signal interference. Because the system and method of the present invention contains information on the last-known position and velocities of all the vessels monitored in its vessel database, it is possible to determine which of those vessels ought to be notified of an interference event in their vicinity. It is also possible for vessels that do not have non-GNSS navigation systems (and thus would not be tracked in the database of the system and method of the present invention) to be subscribers, to be sent alerts when location data of vessels in their vicinity which are part of the database are determined to be anomalous.

[0040] Although anomaly detection using non-GNSS location information has been described before, for example in "Vessel Pattern Knowledge Discovery from AIS Data: A Framework for Anomaly Detection and Route Prediction" (https: / / www.mdpi.eom / 1099-4300 / 15 / 6 / 2218), this sort of detection has been used to identify specific vessel routes and thereafter determine where and when particular vessels deviate from that route, not to determine whether there has been intereference with navigational signals within a particular area or along a well-travelled route.

[0041] The manner in which alerts are sent out to subscriber vessels are sent can be via any number of known mechanisms, including (for aircraft) via air traffic control, (for maritime vessels) via coast guard or other marine agency alerts, plus terrestrial or satellite radio, or other communications systems. In addition, the system and method of the present method could incorporate on-board systems to receive signals that may either simply warn a pilot or navigator that a vessel is entering an area having anamolous or suspected spoofed or jammed GNSS signals, or could be adapted to give the pilot or navigator more comprehensive information such as the location and size of an effected area as well as how that area relates to the current position of the vessel. It is a known problem that some vessels themselves intentionally jam or spoof GNSS location data, or for that matter location data using other navigation systems like ADS-B or AIS data. This is typically done in order to mask illegal activity, e.g., fishing vessels operating in restricted waters, oil tankers carrying sanctions-restricted loads (and thereafter doing mid-sea transfers to other vessels), as well as smugglers. Similar issues may also occur with aircraft engaged in, e.g., drug or arms smuggling. C4ADS (https: / / c4ads.org) is one organization that works to track the activity of vessels which are intentionally sending false location information through location tracking systems to hide or otherwise mask illegal activities. In the system and method of the present system, historic tracks of a vessel's position and velocity at time (PVT), can make it possible to spot anomalies in position and location data that likely caused by jamming or spoofing, even when such jamming or spoofing is done by a tracked vessel itself.

[0042] The method of the present invention ensures accurate location information in a device designed to receive satellite location signals, by providing a plurality of earth-based receivers, receiving location calculation signals at the plurality of earth-based receivers from a constellation of satellites, providing a processing hub in signal connection with the plurality of earth-based receivers, relaying location calculation signals from the plurality of earth-based receivers to the processing hub, and comparing the location calculation signals against known good signal data to identify signals that may not be accurate.

[0043] The receving unit of the present invention is in a vessel, to ensuring accurate navigation when using satellite location signals, and comprises an antenna for receiving location calculation signals from a constellation of satellites, a receiving unit for calculating location based on the signals from the constellation of satellites, the receiving unit including an alert system to receive and transmit an alert signal to a vessel operator which the integrity of the signals received by the receiving unit are determined to be inaccurate.

[0044] BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0045] Figure 1 is an overall view of the method and system of the present invention. Figure 2 show an example of how positional data for any particular vessel is gathered, and how that positional data is determined to be potentially reliable or potentially anomalous, depending on certain set thresholds of positional margins of error.

[0046] Figure 3 shows how weighting of positional signals is used under the system and method of the present invention.

[0047] Figure 4 shows how areas of possible GNSS signal unreliability may be determined, as well as centers or loci from which those areas emanate.

[0048] Figure 5 shows the processing hubs and receivers of one embodiment of the system and method of the present invention.

[0049] Figure 6 is a flow chart outlining the manner in which the system and method of the present invention engages in acquisition of vessel location data.

[0050] Figure 7 is a flow chart outlining the manner in which the system and method of the present invention does initial processing of vessel location data to calculate values useful for categorizing the reliability of that location data.

[0051] Figure 8 is a flow chart outlining the manner in which the system and method of the present invention does categorizes the reliability of that location data and stores that information.

[0052] Figure 9 is a flow chart outlining the manner in which the system and method of the present invention calculates the potential location of a spoofer or jammer, as well as the areas in which GNSS signals should be considered either 'unreliable' or 'partially reliable.'

[0053] Figure 10 is a representation of one embodiment of a user receiver which may be used with the system and method of the present invention.

[0054] Figure 11 is a representation of the manner in which database information may be used by the processing hub of the present invention.

[0055] Figure 12 is a representation of the manner in which global database information may be used by the global processing hub of the present invention. Figure 13 is a flow chart showing operation of an embodiment of the system and method of the present invention, where an alarm condition and a toggle to a backup non-GNSS navigation system is determined and triggered.

[0056] Figure 14 is a flow chart showing operation of an embodiment of the system and method of the present invention, where either manual, or alternate navigation systems, are invoked upon determination that an alarm condition exists.

[0057] Figure 15 is a flow chart showing the manner in which an effected area is determined and an alarm signal and switch to a backup non-GNSS navigation system is sent to a user.

[0058] Figure 16 is a representation of how a global system and method of the present invention may be instantiated across numerous nodes and networks, and how weighting systems for those nodes and networks may be used.

[0059] DETAILED DESCRIPTION OF THE INVENTION

[0060] The system and method of the present invention is designed to ensure a backup system for detecting issues with signal integrity for a GNSS or other geolocation service receiver and sending alerts to vessels that are in vicinities where the integrity of GNSS signals may be questionable or compromised, using in part existing alternative vessel location services as a mechanism to assist in identifying those vicinities. The system and method of the present invention takes advantage of the large number of vessels that are in the process of moving throughout the globe at any one time, the massive amount of location data that many of those vessels generate using non-GNSS location systems, as well as data interpolation and artificial intelligence and / or machine learning systems to extrapolate information using inference, such that accurate approximations of local, regional, or global GNSS signal integrity issues can be identified and alerts sent out to vessels either in vicinities where those issues exist or vessels nearby such areas so that they may avoid area with GNSS signal integrity issues or switch to alternative navigation systems. The system and method of the present invention is advantageous as it can make use of already-existing infrastructure together with supplemented infrastructure and new data gathering, processing and analysis systems. Incoming legitimate GNSS signals from satellites cover a very wide area of earth because they are line-of-sight to receivers and are sent out from a position many thousands of kilometres from receivers which use GNSS signals for navigation. In contrast, incoming signals from a spoofer or jammer, designed to either send false GNSS signals or to interfere with GNSS signals so as to prevent navigation using GNSS, cover a significantly smaller area because they are terrestrially-based, and can cover only a much small area — in most cases, only hundreds of square meters up to, in best cases (with good terrestrial line-of-sight), only a few square kilometres.

[0061] There are two main components to any GNSS signal — the ephemeris and the clock. The ephemeris of a GNSS signal describes the satellites' orbital location, whereas the clock of the GNSS signal provides a reference point for the time-difference calculation used in GNSS signal location calculations using the equation: D = t*c (distance = time * speed-of-light).

[0062] By knowing a particular satellite's position at time t (based on clock and ephemeris information from that satellite's GNSS signal), together with the distance information for four or more GNSS-signaling satellites, the location on earth of any particular receiver may be calculated using trilateration.

[0063] A spoofer may make subtle changes to the ephemeris and / or clock from an incoming satellite signal and then redirect that changed signal to cause a target to go off course, or it may broadcast recorded signals from another time and another place in order to deny service or to bypass time-limits on systems, or to (for instance) keep drones away from a location by simulating a no-fly zone.

[0064] In all GNSS systems except GLONASS (which uses frequency division multiple access (FDMA)) all systems broadcast their signal in Code Division Multiple Access (CDMA), usually around a 1575.32 MHz central frequency. Each satellite in the system has a unique Pseudo Random Noise Code (PRN), which PRN acts as a code allowing the user device to extract its signal. A spoofer can multiplex signals from multiple, faked, PRNs onto the radio signal it emits as a technique for simulating authenticity of the spoofed signal.

[0065] Essentially, this single-frequency multiple-access design simplifies the design of the radio components and shifts complexity to the computational efforts, with the downside that it also simplifies the design of a spoofer or jammer, as computing costs and power (and availability of skilled programmers) are favourable.

[0066] The system and method of the present invention is designed to use non-GNSS signals from a massive number of vessels around the globe to track and project the position and movement of all vessels that are currently in movement around the earth. The system and method of the present invention uses interpolative techniques to make predictive calculations about where any particular tracked vessel may be moving to, and then compares that predicted calculation against GNSS reporting navigational information from that vessel (if any) to determine if the two results are consistent or anomalous. Degrees of anomalousness are determined, and anomalousness over time is also calculated, and all of those calculations are used to weight any particular vessel's reported GNSS positions as being highly reliable, generally reliable, possibly unreliable, and certainly unreliable. For vessels whose GNSS signals are determined to be possibly or generally unreliable, other vessels in the vicinity of that vessel also undergo the same process - navigational information is processed and analyzed in the same way. A global processing hub, or regional or local processing hubs, are used to calculate all data concerning moving vessels, and when possibly or generally unreliable GNSS data is found, regions for which GNSS navigation data is not to be trusted are identified. These regions are calculated using all the vessel information from those regions and adjacent regions, and alerts may be sent out to subscribers to the system to either not rely on GNSS navigation systems if the subscriber's vessel is currently within an unreliable region, or to caution vessels entering that region to rely on non-GNSS navigation systems or possibly to avoid the region altogether. The availability of multiple signals from widely dispersed locations around the globe and from a massive number of data collection points in the form of all in-transit vessels that use and report out GNSS location signals received by their GNSS navigation system provides a high- confidence that 'truth' - the actual signals as broadcast from the satellites, as well as any anomalous signals as the result of GNSS signal interference due to spoofing or jamming - has been captured by the processing hub.

[0067] The processing hub compares the signal(s) received from each tracked vessel's receiver, and compares that signal with known calculated location information for that receiver based upon data from non-GNSS navigation systems, if any, and identifies all signals received which are determined to be inaccurate. All of the data is then processed, using interpolation and weighting function as well as artificial intelligence or machine learning techniques, to map out on a global, regional, or local scale, all areas where GNSS signal interference is predicted to be occurring. This mapping is updated dynamically, so that, for example, moving spoofers or jammers do not result in areas of concern remaining static and not accurately reporting where signal interference exists, as well as to identify when signal interference has been mitigated.

[0068] In the system and method of the present invention, alternative, non-GNSS navigational systems that are used on vessels worldwide are used to determine if GNSS signals in the area in which those vessels are navigating are potentially the subject of interference. Not all vessels will necessarily have these non-GNSS navigational systems on board, nor will all vessels have navigational systems that send out data (either based on GNSS navigation, or non-GNSS navigation) that can be collected and processed. Nevertheless, because of the many thousands of vessels worldwide, and many hundreds of vessels in any particularly large region, that do have some sort of navigational system from which data can be collected, the system and method is able to calculate the approximate location and size of any particular region that may be subject to spoofing or jamming, and send out alerts to subscribers to the system about the location and size of those regions so that the pilot or navigator of the subscriber vessels can make decisions about whether certain areas should be avoided because of spoofing or jamming, or to rely on navigational systems considered to be reliable because they are not subject to spoofing or jamming. If it is calculated, over a designated period of time and for a sufficiently large number of vessels in a particular region, that incoming signals from the GNSS navigation systems from those vessels deviates from the expected location information by more than a configurable threshold (which threshold may be set to account for variations in signals based on wind, weather or current deviations that might cause deviations in expected location, or other known signal varying events), the system can use weighting functions to determine how likely any particular area within a region is subject to potential spoofing or jamming of the GNSS system in that region, can calculate where the spoofing or jamming may be occurring and over how wide and area, and then send out alter information to subscribers as to the location and size of regions subject to spoofing or jamming. The alert contains information about the affected region, the time the event began, the duration of the event and whether the event is ongoing, as well an identification of the particular signals which are affected. The processing hub or hubs may be designed and programmed to identify a region which is subject to jamming or spoofing, by making calculations triangulated from information from the multiple vessels, and may identify latitude, longitude and radius information for the spoofed signal or jamming signal, thereby identifying and discarding other signals that may be transmitted through, and therefore effected by, the false or jammed signal. As a result, the invention of the present invention can also allow individuals to narrow down the location of the spoofed or jamming signal, and direct them to that location to take mitigation steps to remove that signal from the area of interest, or to steer the user away from that area to an area where spoofing or jamming is calculated to not be occurring. The alert and related data are all recorded for later analysis, to thereby help in doing forensic analysis of the manner and techniques used in spoofing or jamming, thereby improving the ability to identify and mitigate future efforts to spoof or jam.

[0069] A false alert from the processing hub can be as disruptive to effective location services and navigation as a true spoofing event. To avoid false alerts, the present invention may include thresholds set in the processing hub, so as to account for minor variations in true location signals and therefore not trigger an alert in that circumstance. An alert has additional seriousness if it is ongoing, and / or if multiple GNSS stations detect the spoofing event, as the distance between stations implies that the spoofer has a high-power level and is impacting many end users.

[0070] In the present invention, alerts and relevant data about the alert may be saved in a database. Statistical data can be generated related to the frequency, intensity, and sophistication of spoofing events and this data can be made available to interested parties, e.g., aviation and radio communication authorities, as a mechanism to identify trends and areas most susceptible to these activities, as a way of developing newer interdiction and mitigation steps. This information may also be used to continuously train the system on where, how, and when spoofing or jamming events are occurring around the globe, how those spoofing or jamming events are reflected in both the inaccuracy of GNSS navigational signals on vessels subject to it and the differences between the GNSS navigational signals and non-GNSS navigational signals. All of this data is useful in ensuring the system and method of the present invention is constantly improving, and learnings from regions where spoofing or jamming is found can be used to improve the navigational and alerting systems globally. Figure 1 shows one implementation of the system and method of the present invention. In the implementation of Figure 1, a region for which efforts to spoof or jam geolocation signals is shown. In the region shown in Figure 1 a GNSS geolocation system is in place in order to allow GNSS navigation in that region. Multiple GNSS satellites S1, S2, S3, S4 are located in orbit around the earth, and generate GNSS signals including both ephemeris and clock data. In the region shown in Figure 1, both aircraft A1, A2, A3 and marine vessels M1, M2 and M3 are navigating through the region. The region in Figure 1 is also subject to the spoofing or jamming of GNSS signals from the GNSS satellites S1, S2, S3, S4 by two different spoofers or jammers S / J1 and S / J2. Spoofer or jammer S / J2 is generally land based, and in the region showing in Figure 1, is generally designed to spoof or jam GNSS signals used by aircraft A1, A2, A3 to navigate within zone Z2. Spoofer or jammer S / J1 is generally sea based, and in the region showing in Figure 1, is generally designed to spoof or jam GNSS signals used by marine vessels M1, M2, M3 to navigate within zone Z1. The spoofer of jammers S / J1 and S / J2 have been placed by persons or entities wishing to disrupt accurate location by the vessels A1, A2, A3, M1, M2 and M3 using a signal which covers spoofing or jamming zones Z1 and Z2, to, for example, disrupted accurate and safe navigation, take-off or landing, in the case of aircraft A1, A2, A3, or navigation or docking, in the case of marine vessels M1, M2, M3, or navigation, in the case of autonomous vehicles (not shown).

[0071] In the implementation of the present invention of Figure 1, there are multiple non-GNSS receiving stations R1- R8 located around the location of interest shown in Figure 1, where accurate and complete location information is desired. As shown in Figure 1, the receiving stations R1-R3 are generally designed to receive, for example, ADS-B information from aircraft A1-A3, while receiving stations R4-R8 are designed to receive, for example, AIS information from marine vessels M1-M3. In nautical applications, such as location information for marine vessels approaching a harbour, the receiving stations R4, R5, R6, R7, R8 would be located on shore or possibly on secure stationary buoys; in aviation applications, there would be more flexibility in locating the stations R1, R2, R3 at various secure locations, which could be on land, at sea, or in air. A spoofer or jammer S / J1 has been placed by a person or entity wishing to disrupt navigation and location information from the geolocation system within the zone Z1, with a signal radiating in a circle of hundreds of meters in radius, while a spoofer or jammer S / J2 has been place by a person or entity wishing to disrupt navigation and location information from the geolocation system within the zone Z2. Note that in the example shown in Figure 1, the receivers are describe as being capable of receiving data signals of a particular type (ADS-B or AIS), the receivers are not so limited; any or all of the receivers R1-R8 could be configured to receive both ADS-B or AIS data signals, or for that matter any other data signal intended to convey navigational information about vessels A1-A3 and M1-M3 that are navigating through or around regions of interest and for which it is desired to determine if GNSS signal spoofing or jamming is occurring.

[0072] In one embodiment of the present invention, the system and method uses information from existing Automatic Dependent Surveillance-Broadcast (ADS-B) - for aircraft vessels - and Automatic Identification System (AIS) - for naval vessels - to interpolate location information for vessels in a particular area of interest, compare that interpolated location information against GNSS signal data for the same location, and via weighting algorithms, assign degrees of risks of jamming, spoofing or other intereference of GNSS signals within regions around the globe. Both ADS-B and AIS track the last known locations of aircraft and maritime vessels, respectively. Although these location tracking technologies are not currently being used in order to determine whether GNSS signals are being jammed or spoofed or otherwise have lost integrity, the present invention uses those systems to serve as indicators of jamming and spoofing, by calculating when vessels using those technologies 'lose position,' or suddenly show up elsewhere, or elsewhen ,than anticipated.

[0073] The receiving stations R1, R2, R3, R4, R5, R6, R7, R8 may be existing receiving stations that have already been put in place to receive navigational signals, or they may be added receiving stations specifically designed to supplement existing receiving stations so as to provide better coverage for ADS-B or AIS data signals in areas where there is concern that GNSS navigational signals are subject to spoofing or jamming, so as to provide more than adequate coverage for the region shown in Figure 1 where there is a need to detect such spoofing or jamming and where location accuracy is required. At least some of the receiving stations R1, R2, R3, R4, R5, R6, R7, R8 are also configured to receive GNSS signals being reported from the vessels A1-A3 and M1-M3 so that that information may be used to monitor reported GNSS signals to determine if they are in any way anomalous. The purpose of the receiving stations R1, R2, R3, R4, R5, R6, R7, R8 is to allow a processing hub P to collect navigational data using a system other than GNSS so that the accuracy of GNSS signals in particular zones within that region can be validated as generally accurate, or to determine whether there are zones Z1 and / or Z2 where GNSS signals are likely being spoofed or jammed, and thus to determine if true GNSS signals from satellites S1, S2, S3, S4 or false GNSS signals from spoofers or jammers S / J1 or S / J2 exist within zone Z1 or Z2. By doing comparisons of GNSS signals reported by vessels within zones Z1 and Z2 against ADS-B and / or AIS data signals in those zones, general information about the integrity of the GNSS signals in those zones can be extracted. In the system and method of the present invention, these comparisons, including comparisons as to predicted versus reported navigational information, correlations between navigational signals reported from multiple vessels within those zones, and predictive algorithms extracted from that data using long-term analysis, can lead to accurate assessment of where zones of high risk of GNSS signal interference or non-integrity exist, and this assessment can be constantly updated and revised in real-time, so as to report out to subscribers to the system and method of the present invention where zones such as Z1 and Z2 - where GNSS signals should not generally be trusted due to spoofing or jamming from spoofers or jammers S / J1 and S / J2, the location of such zones, the area of such zones, and possibly the trajectory of such zones if the spoofers or jammers S / J1 and / or S / J2 are non-stationary. As a result, subscribers to the system and method of the present invention can make navigational decisions to either avoid zones Z1 or Z2 in which it is known GNSS signal integrity has been compromised, or to switch over to alternative, non-GNSS, navigational systems when moving through or around those zones.

[0074] In the system and method of the present invention, ADS-B and / or AIS data feeds are received as inputs into a processing hub P or processing hubs, which uses information from those data feeds to detect anomalous location data, correlate that anomalous location data with other data from vessels in a similar area, apply interpolative and weighting calcinations to the data feeds, and as a result detect areas or locations which may be subject to jamming or spoofing of GNSS signals. For any such areas, vessels which subscribe to the system of the present invention and which need to be alerted that they are in an area of jamming or spoofing can be identifed and alerted.

[0075] Each of the receiving stations R1, R2, R3, R4, R5, R6, R7, R8 are in signal communication via secure network N with processing hub P, which may be located at a central location near, or within, the region being monitored, or could be a global processing hub for all locations around the globe being monitored; it is also possible that multiple local processing hubs P are used to collect, collate, and process data from their respective local regions, and each of those local processing hubs in turn send their collected and processed data to global, or mega- regional processing hubs which can be used to extract information worldwide or in larger regions collecting data from a plurality of regional processing hubs P. Processing hub P may also serve multiple areas for which location accuracy is needed, providing signal processing services for other banks of receiving stations covering other areas. In the embodiment of Figure 1, signal communication is achieved using a secure, hard-wired network N to prevent interference with the signals sent to processing hub P; in an alternative embodiment, the network N can be created using a wireless encrypted or otherwise secure technology to ensure signal integrity to processing hub P.

[0076] The processing hub P receives signals from the receiving stations R1, R2, R3, R4, R5, R6, R7, R8 with enough redundancy to be able to receive signals transmitted from vessels A1-A3 and M1-M3, of whatever form those vessels broadcast navigational signals - be they GNSS, ADS-B, AIS, or any other navigational reporting system. The first order of detection is to recognize that there is an inconsistency in any GNSS reported navigational data from any of the vessels that transmit their GNSS navigational data, when compared to the non-GNSS navigational data that any vessels within a certain vicinity of the GNSS-reporting vessels. In this way, an initial level of identification of where there may be GNSS data integrity anomalies may be discerned. The next order of detection is to be able to confidently ascertain whether the correct GNSS signal is at any location of vessels that are sending GNSS signals to the receivers R1-R8.

[0077] In order to allow for the system and method of the present invention to work effectively, there needs to be a sufficient number of vessels sending navigation data - both GNSS and non-GNSS, although no one vessel needs to report both - that are within a general vicinity of one another, across a sufficiently diverse area to be able to confidently say, for example, that 3 of 10 vessels are reporting GNSS signals that are consistent with - within certain thresholds of disparity between GNSS and non-GNSS signals - the non-GNSS navigational signals being reported by any vessels in the vicinity of those vessels reporting GNSS data, but 7 of 10 vessels are reporting GNSS signals that are not consistent with non-GNSS navigational signals from vessels in the same vicinity, and therefore the 3 vessels must be in a zone where the correct satellite signals are being received, whereas the 7 vessels must be in a zone where a spoofer or jammer attempting to compromise GNSS receiving at least in the area of those 7 vessels. The best way to achieve an effective system and method that effectively detects attempts to compromise is to use a highly distributed network of receivers, and a sufficiently large number of vessels transmitting navigation signals within an area of interest, and a sufficient number of receivers able to receive those signals in a way that can be determined to have a high degree of confidence. Thus, a system and method of the present inventions configured in that manner allows for a confident determination that, for example, the GNSS signals from vessels A3 and M2 are highly likely to be compromised, the GNSS signals from vessels A2 and M3 have some potential to be compromised (because those signals emanate on the border of the zones Z2 and Z1 subject to spoofing or jamming from spoofers or jammers S / J2 and S / J1), and that the GNSS signals from vessels A1 and M1 are not compromised. As discussed in more detail below, each of these analyses is done via an algorithmic system which assigns weighting to the vast number of navigational signals received, as to the relative confidence level of any one specific set of signals for one particular vessel. As the result of sufficiently large number of data sets for a large number of vessels, these confidence levels can be used to extract information about the relative certainty that GNSS signals are being disrupted in some fashion in any particular location, and can assign degrees of confidence to the locations from which such disruption is likely occurring, and also the area that is being affected by such disruption. In this way, the system and method of the present invention allows not only for alerts to be provided to subscribers to the system and method of the present invention that GNSS signals in identified areas are not to be trusted, and that either alternative navigation systems should be used for vessels in that area, or that vessels should take steps to avoid the identified area if they wish to continue to rely upon GNSS-based navigation systems.

[0078] Because it is not known beforehand the scope of spoofing or jamming that may be affecting the zones Z1 and Z2, the system and method of the present invention is prepared to assume that multiple reporting vessels are being simultaneously affected. In order to discern true from false (or incomplete or non-existent) reported GNSS navigational data, and thus the zones where GNSS signals may be compromised, the system and method of the present invention relies upon a number of geographically distributed receivers R1- R8 so that the system and method of the present invention can gather navigational data from as many vessels that are transmitting navigational data, both GNSS and non-GNSS, as possible in a region of interest.

[0079] As an example, if a single satellite signal is being spoofed or jammed by spoofer or jammer S / J1 or S / J2, the processing hub P will receive signals from a number n of receivers R1, R2, R3, R4, R5, R6, R7, R8. At t0, all n receiving stations R1, R2, R3, R4, R5, R6, R7, R8 should report the same clock and ephemeris info for a particular satellite. If the processing hub P receives one signal from one or more of the receiving stations R1, R2, R3, R4, R5, R6, R7, R8 which is different from the others in clock or ephemeris, then there is a very high probability that that particular satellite's signal is being spoofed.

[0080] The system includes a mechanism to detect and exclude corrupt messages. The messages from the satellites S1, S2, S3, S4 include a cyclic redundancy check (CRC) which is intended to allow the receiver to detect and exclude messages that have been corrupted in transit - whether intentionally or not, corruption in transit is a fact of data communications. Occasionally a message will be corrupted but still pass a CRC check - this is a matter of statistical probability. The system will be configured to ignore N suspect messages from a particular station where the default for N is 1.

[0081] If the hub receives several signals from receiving stations R1, R2, R3, R4, R5, R6, R7, R8 which deviate from expected signals, then the signal which is consistent between the most receivers is deemed to be correct, ("Majority voting"). Clearly this scheme would have little validity if there were only a small number of receivers in proximity — it would be reasonable to anticipate a spoofing episode that affected, say, three out of four receivers. For this reason it is important to have sufficiently large number of receivers distributed over a sufficiently large area that any single spoofer or jammer is unable to overwhelm or outnumber the 'truth.'

[0082] Each vessel A1-A3 and M1-M3 using the ADS-B or AIS systems has a unique identifier which it broadcasts along with its position and navigation status, so nearby vessels can navigate safely and avoid collisions. The ADS-B and AIS systems currently use terrestrial and space-based receiver networks which monitor and aggregate this position and navigation status data, and in some cases those receiver networks make the data available to interested parties, other than to nearby vessels receiving the data for collision avoidance. In the system and method of the present invention, existing terrestrial- or spased-based receivers are configured to, and supplemental or new receivers are installed, so as to provide an array of receiving stations R1, R2, R3, R4, R5, R6, R7, R8 to allow continuous, and redundant, reception of both reported GNSS and non-GNSS location data for all vessels A1-A3 and M1-M3 in regions of interest and for which it is desired to locate and provide alerts - or mitigation measures - for any spoofing or jamming activity from spoofers or jammers S / J1 and S / J2.

[0083] Figure 2 shows the manner in which the system and method of the present invention uses received navigational signals in order to determine whether received GNSS navigational signals are anomalous or should be considered to be reliable. A vessel at position P1 sends navigational signals to any of (or multiples of) the receiving stations R1, R2, R3, R4, R5, R6, R7, R8. In the example shown in Figure 2, the position P1 is one that has been determined to include reliable GNSS navigational data, and the vessel at that position is one that transmits both GNSS navigational data and non-GNSS navigational data. Subsequently, that vessel moves to a new position. As shown in Figure 2, there is a position P2R that represents the position that the GNSS navigational system on that vessel transmits and which is received by one or more of the receiving stations R1, R2, R3, R4, R5, R6, R7, R8. At or around the same time, the non-GNSS navigational system transmits positional information for the same vessel, which can be one of two possible alternatives: position P2A or position P3A. In the case of position P3A, the GNSS reported position P2R is reasonably close to the non-GNSS reported position P3A - as represented by either a vector V3 between the GNSS and non-GNSS reported positions P2R and P3A, or by an angle θ3 and distance D3 between the GNSS and non-GNSS reported positions P2R and P3A - such that the GNSS position P2R falls within a 'margin of error' or tolerance threshhold T, wherein the GNSS reported position P2R can generally be assumed to be accurate, as that position falls within that threshhold T. In contrast, if the non-GNSS navigational system for that vessel reports position P2A, and the GNSS navigational system for that vessel reports position P2R, then the GNSS system reported position - as represented by either a vector V2 between the GNSS and non-GNSS reported positions P2R and P2A, or by an angle θ2 and distance D2 between the GNSS and non-GNSS reported positions P2R and P2A - falls outside of the 'margin of error' threshhold T for the non-GNSS reported position P2A for that vessel, and the GNSS positional data for that vessel can be flagged as potentially anomalous. Any vessel for which the system and method of the present invention has flagged as reporting anomalous GNSS positional data would also be flagged for the collection of additional data with regard to the differences between the GNSS reported positions P2R and non-GNSS reported positions P2A or P3A, as a mechanism to see if there is a continued trend of divergence between the GNSS and non-GNSS positional data beyond the margin of error threshhold T, such that that vessel should be identified as being located in an area where GNSS reported navigational data is unreliable and thus potentially subject to spoofing or jamming. The continued collection of data on that particular vessel, if navigational data continues to show discrepancy between GNSS and non-GNSS data beyond threshhold T, would continue until the GNSS and non-GNSS data shows a pattern of falling within threshhold T. All positional data outside of threshhold T would be flagged in a database DB at processing hub P as reflecting locations at which GNSS navigational data should be considered to be unreliable - thus reflecting the zones Z1 or Z2 where spoofing or jamming can be assumed to be occurring, and the processing hub P can use the flagged location data to extrapolate note only the areas of zones Z1 or Z2, but potentially also the locus or center of zones Z1 or Z2, and thus the potential location of any spoofer or jammer S / J1 or S / J2 that is the source of GNSS signal anomalies. The area data of zones Z1 or Z2 can thus be used to send alerts to all vessels within a region where zones Z1 or Z2 are located, directing those vessels to either avoid the areas of zones Z1 or Z2 or to rely on non-GNSS navigational data when navigating through those areas. The location data of any spoofer or jammer S / J1 or S / J2 that is extracted from the vessel navigational data and calculated areas of zone Z1 or Z2 can also be used to potentially direct ameliatorive or destructive actions against spoofer or jammers S / J1 or S / J2 so that the GNSS navigational disruption by those devices may be eliminated or countered.

[0084] Figure 3 is a representation of the manner in which the system and method of the present invention assigns weights to the incoming navigational data from any particular vessel. As discussed above, a vessel navigates from a position P1 - which position P1 is generally determined to have accurrate GNSS navigational data - to a different position. The GNSS navigational system on that vessel reports out a subsequent position P2R, whereas the non- GNSS navigational system on the vessel reports a subsequent position, either P2A, P3A, or P4A. In the case of position P3A, that position falls within a predetermined threshhold T of the GNSS reported location P2R such that the GNSS and non-GNSS reported positions are determined to be close enough to one another (as measured by either a vector V3 between the GNSS and non-GNSS reported positions P2R and P3A, or by an angle θ3 and distance D3 between the GNSS and non-GNSS reported positions P2R and P3A being smaller than some predetermined value), that any GNSS position P2R is flagged by the system and method of the present invention as "reliable" and thus not subject to spoofing or jamming. In the case of position P2A, that position falls outside a predetermined threshhold T2 of the GNSS reported location P2R that the GNSS and non-GNSS reported positions are determined to be so far apart from one another (as measured by either a vector V2 between the GNSS and non-GNSS reported positions P2R and P2A, or by an angle θ2 and distance D2 between the GNSS and non-GNSS reported positions P2R and P2A being larger than some predetermined value), such that any GNSS positions P2R are flagged by the system and method of the present invention as "unreliable" and assumed to be subject to spoofing or jamming. In the case of position P4A, that position falls between the predetermined thresholds T and T2 of the GNSS reported location P2R such that the GNSS and non-GNSS reported positions are in-between the thresholds of "reliable" and "unreliable" (as measured by either a vector V4 between the GNSS and non-GNSS reported positions P2R and P4A, or by an angle θ4 and distance D4 between the GNSS and non-GNSS reported positions P2R and P4A being between the two predetermined values represented by T and T2), such that any GNSS position P2R is flagged by the system and method of the present invention as between "reliable" and "unreliable" and thus possibly, but not assuredly, subject to spoofing or jamming. In the case of reported non- GNSS reported position P4A, a weighting value W of signal "reliability" is assigned depending on the reported value (as measured by either a vector V4 between the GNSS and non-GNSS reported positions P2R and P4A, or by an angle θ4 and distance D4 between the GNSS and non-GNSS reported positions P2R and P4A being between predetermined values represented by thresholds T and T2). In the case where the measured values are equal to or less than threshhold T, the weighting value would be "0" (representing "reliable"); in the case where the measured values are equal to or more than threshhold T2, the weighting value would be "1" (representing "unreliable"); in the case where the measured values are between T and T2, the weighting value would be assigned based on the closeness to either threshhold T or T2, such that measurements halfway between T and T2 would be assigned a weight of "0.5," whereas a measurement that is % between T and T2 would be assigned a weight of "0.25." As a result, these weightings can be used to assign degrees of potential reliability of GNSS position signals for any particular vessel, which in turn the system and method of the present invention can use as part of the processing of large collections of vessel positioning data to extract information, and trends, concerning where, and when, GNSS signal interference - typically as the result of spoofing or jamming - can be continuously monitored, updated, and reported to subscribers.

[0085] Figure 4 is a representation of the way that the system and method of the present invention uses data from a large number of vessels to create a mapping of areas that may be subject to GNSS signal intereference via spoofing or jamming. Using the techniques described above, the system and method of the present invention assigns to all tracked vessels a weighting value W as to the reliability or unreliability of the GNSS signals reported out by any particular vessel. As shown in Figure 4, out of a large group of vessels, there will be some vessels L for which the GNSS reported position data is considered to be 'reliable.' Also out of that large group of vessels, there will be some vessels U for which the GNSS reported position data is considered to be 'unreliable.' Finally, there will be, out of that large group of vessels, some vessels G for which the GNSS reported position data is considered 'possibly reliable, possibly unreliable' according to a weighting value W assigned to that vessel as described above. Gathering all the data for all the vessels, both the reliable L, unreliable U, and possibly reilable / possibly unreliable G allows for the mapping of areas where there is some question about the reliability of the GNSS location data transmitted from within those areas. A 'do not rely' area D may be mapped (using known techniques for mapping circular or ellipsis areas from data points assumed to be within that area, such as Monte Carlo techniques) that encompasses all the vessels considered to have unreliable U GNSS location data. In turn, using mathematical techniques, the location of the center of the circle (or loci of an ellipsis) C representing both the center of the 'do not rely' area D as well as the probably location of, or at least a location likely to be near to, any spoofer / jammer S / J that is causing the unreliabilty of GNSS location data with the 'do not rely' area D. That center or loci C can in turn used to send mitigation or counter techniques - up to including distructive measures - to address or remove any spoofing or jamming activity in the 'do not rely' area. At the same time, the 'do not rely' area - both location and extent / radius - can be transmitted to any vessels subscribing the system and method of the present invention, so that those vessels have real time, active, and continuously update information about areas to either avoid, or within which they should not rely on GNSS navigational systems for navigation. As also shown in Figure 4, the system and method of the present invention can also make a determination as to a 'possibly unreliable' area E. The 'possibly unreliable' area E would encompass both the 'do not rely' area D as well as an area that would include any vessels G with a weighted value W greater than 0 but less than 1 as to the reliablity of the GNSS signals eminating from those vessels. As with the 'do not rely' area D a center or loci C could be calculated for the 'possibly unreliable' area E (which may or may not coincide with the center or loci C of the 'do not rely' area D although would likely be very near or coextensive with the center or loci for the 'do not rely' area D. The 'possibly unreliable' area E could be calculated to include an area that is anywhere between being identical to the 'do not rely' area D (i.e., has a weighting value that is no less than '1') to an area where any vessel recording any degree of unreliability of its GNSS location signal (i.e., has a weighting value W up to but not including '0'). The degree to which any particular weighting value W is used to calculate the 'possibly unreliable' area E could depend upon a variety of factors, which could include the degree to which any particular region is considered to be more or less susceptible to spoofing or jamming (such that areas considered more susceptible to spoofing or jamming would likely calculate larger 'possibly unreliable' areas E encompassing a larger range of weighting values W and thus consider that entirely 'possibly unreliable' area E one to avoid or to not rely upon GNSS navigation within), or could be tailored to any particular subscriber (where some vessels - perhaps those with more valuable cargo or more susceptible to adverse activities by those seeking to spoof or jam GNSS signals used by those vessels - would wish to have a larger 'possibly unreliable' area E reported - whereas other subscribers - for example, empty vessels or civilian vessel that would be less likely to be targets of those who might be attempting to spoof or jam GNSS signals in the areas in which they are navigation).

[0086] As part of the system and method of the present invention, a database of aircraft and maritime vessels is maintained, and that database is constantly and continuously updated when new vessel position, velocity and navigation status data become available, based on the inputs from ADS-B and AIS systems. Although the ADS-B and AIS systems are exemplary examples of position, velocity and navigation status data inputs into the system and method of the present invention, other current, or future, non-GNSS systems for collection of navigational information about moving vessels of any type may also be used as inputs. In the system and method of the present invention, when a vessel's navigation data changes more than an expected threshold T, then an exception is raised as to that vessel. A single exception may be treated as a tempoary anomaly, such as the result of temporary signal degradation or of noise. However, additional navigation data for that vessel which continues to be identified as an exception may be used to indicate that GNSS signals for the area through which that vessel is navigating could be compromised. Additionally, if multiple vessels in the same vicinity report similar exceptions at the same time, this indicates a high probability of interference of the GNSS signals in that vicinity.

[0087] The system and method of the present invention is computationally and data-traffic intensive. At present adoption rates of the ADS-B and AIS navigation systems, the system and method of the present invention is designed to track about 10,000 aircraft and 550,000 maritime vessels worldwide. Not every one of these vessels are in motion at any one time, as aircraft may be on the ground and maritime vessels in port or in dry dock. Neverthelss, at any point in time, some significant percentage of these vessels are in motion somewhere around the world.

[0088] In the system and method of the present invention, not every vessel that is in-motion and has a operational navigation system like ADS-B or AIS may have data collected; the system and method of the present invention may monitor only a subset of these vessels - for example, those that are navigating through locations where there is a high confidence that GNSS signals are not subject to potential interference, and thus any anomalous location data has a higher likelihood of being the result of temporary, natural, phenomena, may not be monitored. In addition, the system and method of the present invention may not even choose to collect data from all vessels in a particular location even when that location could be the subject of intentional interference with GNSS signals. As an example, the People's Republic of China alone has about 200,000 fishing vessels - nearly half of all maritime vessels that could be subject to monitoring using the system and method of the present invention. However, many of those 200,000 vessel work in the same vicinity, and monitoring all vessels in the same vicinity may be duplicative of the information which the system and method of the present invention needs to detect unnatural GNSS signal interference. In the case where there may be an excess of location data for a particular area, the system and method of the present invention can use statistical methods to sample from that dataset and still achieve the desired results without having to process excess data which does not add to the overall accuracy of the output.

[0089] Figure 5 shows the data communication and data processing feature of the system and method of the present invention. As discussed in more detail above, a processing hub P receives signals via network N from the receiving stations R1, R2, R3, R4, R5, R6, R7, R8 with enough redundancy to be able to receive signals transmitted from vessels A1-A3 and M1-M3. Processing hub P includes a database DB which records data from all of the monitored vessels from which location information is received from receiving stations R1, R2, R3, R4, R5, R6, R7, R8. Processing hub P can be a regional processing hub covering a subsegment of the globe, and can be in network communication via a global network GN with a global processing hub GP with its own global database GDB, which is used to coordinate, update, process, and provide alerts to subcribers on a world-wide basis, if the subscriber has a world-wide subscription. Global processing hub GP and global database GDB can also be used to process data that represents vessel data collected between the regions that any particular regional processing hub P covers, so that there are no gaps in location data processing and coverage in regions which are interstitial between two or more regional processing hubs P.

[0090] In the system and method of the present invention, a global database GDB may be maintained of all vessels across the globe that have navigation systems which are capable of being monitored - whether they be GNSS, ADS-B, AIS, or any other existing or future navigation system which sends out signals that may be received so as to determine the location that that navigation system is reporting for the vessel which uses the navigation system. All navigation data from these navigation systems from all vessels globally is fed into the system and method of the present invention. The global database GDB, in order to more efficiently extract location data and determine the extent to which GNSS signals are subject to interference, will designate some vessel data as 'inactive' - for vessels that are known not to be actively moving -- or assume that certain vessels should generally be considered to be receiving accurate GNSS signals - for vessels moving through regions where there is a high degree of confidence that the GNSS signals in those regions are accurate. The navigation data from the remaining vessels will be considered within the database DB to be 'active.' In order to make efficent use of processing resources in the processing hub or hubs P and GP of the system and method of the present invention, the database DB of all vessels gets updated navigational data on a periodicity that is longer than the updating periodicity of the subdatabase of all 'active' vessels - for example, the 'all' database DB gets updated once an hour, whereas the 'active' subdatabase gets updated every 10 seconds, with vessels moving from the 'all' database DB to the 'active' subdatabase as variations in their location data are detected to meet a criteria set to identify 'active' vessels. Similarly, vessels in the 'active' database can be moved to the 'all' database DB when they have moved to a location designated to be a location of inactivity (for example, a harbor or an airport), or a location for which active monitoring is determined to not be desirable or useful (for example, a location known to be relatively safe from potential GNSS signal interference).

[0091] In the system and method of the present invention, each vessel in the 'active' database will have an an expected next position based on its location, velocity, and other parameters sent from the non-GNSS navigational system on-board the vessel. If a vessel's GNSS next position report is anomalous from the expected next position on that vessel, then the system and method of the present invention flags that vessel as potentially subject to GNSS signal interference, but does not initially designate the location of that particular vessel as being the subject of GNSS signal interference. Thereafter, for that flagged vessel, if the anomalies are consistent and / or there are other vessels in the vicinity of that flagged vessel are also exhibiting similar location anomalies, then the system and method of the present invention will presume that interference is present in and around the flagged vessel.

[0092] In the system and method of the present invention, all the vessel data, location expected, and actual vessel position information based on non-GNSS data terrestrial networks, GNSS data for the same vessels, individual flags for all vessels, and correlations between vessels in the vicinity of other vessels is coupled together to form a comprehensive picture of locations around the globe where pattern of anomalous GNSS vessel location data is being reported. The system and method of the present invention uses that comprehensive data to calculate probabilities about the extent to which certain locations around the globe are highly likely to be subject to GNSS signal interference of some sort, to create an incident database concerning those locations, and issuing alerts to subscribers to the system and method of the present invention, so that they may be alerted that they are about to enter, or are indeed within, a location where GNSS navigation data should not be relied upon as a result of GNSS signal interference. Because the system and method of the present invention contains information on the last-known position and velocities of all the vessels monitored in its vessel database, it is possible to determine which of those vessels that are subscribers to the system and method of the present invention ought to be notified of an interference event in their vicinity. It is also possible for vessels that do not have non-GNSS navigation systems (and thus would not be tracked in the database of the system and method of the present invention) to be subscribers, to be sent alerts when location data of vessels in their vicinity which are part of the database are determined to be anomalous.

[0093] The manner in which alerts are sent out to subscriber vessels are sent can be via any number of known mechanisms, including (for aircraft) via air traffic control, (for maritime vessels) via coast guard or other marine agency alerts, plus terrestrial or satellite radio, or other communications systems. The system and method of the present invention can also include a dedicated alerting system, including potentially dedicated alerting hardware and software installed on-board any vessel which a subscription, that can provide very specific information about GNSS interference, including areas D or E of such interference, adapted to the preferences of a particular subscriber as to the degree of "possibly invalid" GNSS signal data has been determined by the weighting value W that that particular subscriber wishes to have ascribed to any particular areas where GNSS signals may be anomalous.

[0094] It is a known problem that some vessels themselves intentionally jam or spoof GNSS location data, or for that matter location data using other navigation systems like ADS-B or AIS data. This is typically done in order to mask illegal activity, e.g., fishing vessels operating in restricted waters, oil tankers carrying sanctions-restricted loads (and thereafter doing mid-sea transfers to other vessels), as well as smugglers. Similar issues may also occur with aircraft engaged in, e.g., drug or arms smuggling. In the system and method of the present system, historic tracks of a vessel's position and velocity at time (PVT), can make it possible to spot anomalies in position and location data that likely caused by jamming or spoofing, even when such jamming or spoofing is done by a tracked vessel itself. Thus, national or international vessel monitoring agencies - such as national navies, air defense forces, or coast guards - can subscribe to the system and method of the present invention as a mechanism to detect anomalous navigational data for vessels of interest for which there may be levels of concern that such a vessel might be 'self-spoofing' its navigational data in order to circumvent national or international maritime or aviation laws. The system and method of the present invention can include a receving unit in a vessel specifically designed to receive alerts as to navigational anomalies which that particular vessel might be subject, and may send out alerts to that vessel that could include information about the location and size of any area for which GNSS navigational data is not to be trusted or which may not be of complete trust. This receiver can include an antenna for receiving alert signals from the system and method of the present invention, an alert signalling system to provide alerts to the vessel, a display system to display information about the location and area where anomalous GNSS signals may be occurring, and may also include a tie into the vessel's own navigational sytsem, so that information concerning the location and area of anomalous GNSS signals may be mapped against the navigational information presented to a pilot or navigator, so that appropriate steps can be made in navigating the vessel based on that information.

[0095] Figure 6 is a flow chart showing how vessel location information is initially acquired by the system and method of the present invention. Location signals (both GNSS and non-GNSS) are received by receivers R1, R2, R3, R4, R5, R6, R7, R8, from vessels that are within transmission range of those receivers. All of these signals are relayed to processing hub P. Processing hub P then takes the location signals from all vessels that have been acquired by any of the receivers to which it is in network connection via network N. The first level of analysis is to determine whether any particular vessel should be assigned 'active' or 'inactive' based on stored location information for that particular vessel from the last location signal acquisition period. A comparison is made of the most recently acquired location information for a particular vessel against the last acquired location signal for that vessel. If the two locations fall within a particularly small threshold (for example, a few meters) that vessel may be assigned as 'inactive' under the assumption that that lack of movement indicates that the vessel is in an airfield, harbour or dry dock. Note that additional information (such as where on the globe the two locations may be found) may be used as part of this calculation. As an example, two locations that fall within the threshold but which are nowhere near land (for a marine vessel) or a known airfield (for an aircraft) may not be assigned 'inactive' status under the assumption that that vessel may be anchored or hovering. Vessels assigned to 'inactive' status will have a longer period assigned for subsequent location data acquisition via a delay - for example, 'inactive' vessels may have subsequent location data acquired only on a periodicity of 10 minutes or longer. After that period has elapsed, new location information for that vessel is acquired.

[0096] If the two compared location values are outside of the assigned threshold, that vessel will be assigned 'active.' For vessels assigned as 'active' a shorter periodicity of location signal acquisition is assigned (for example, on the order of every 10 seconds). Location signals for that particular vessel will continue to be acquired, and stored for further processing, at that periodicity, until conditions are detected so as to establish that that vessel is now 'inactive.'

[0097] All of the signal information from receivers R1, R2, R3, R4, R5, R6, R7, R8 are sent to processing hub P. The processing hub P includes electronic storage (such as a hard drive) in which a database or databases DB are stored. The database DB may contain previously stored, or otherwise calculated, known and accurate location and clock data for each of the receivers R1, R2, R3, R4, R5, R6, R7, R8. As described above, in a first instance the processing hub P compares the location signals received from each receiver for any particular vessel to the stored identification, location and possibly clock data for that vessel at the last instance at which it was recorded, and makes a comparison of the two location values against an 'active' / ' inactive' threshold value (on the order of several meters) to make a determination as to whether that particular vessel should be assigned 'active' or 'inactive' status. The threshold value may also have a factor related to the location at which the vessel is found, such that certain locations (harbours, dry docks, airfields) at which location data shows no movement beyond the threshold value will cause the database value for the state of that vessel to be set at 'inactive' whereas if the location is in an area where the vessel may be active but not moving sufficiently (for example, due to being anchored at sea), the 'inactive' value may be triggered only if there is no movement of the vessel beyond the threshold for multiple cycles.

[0098] Processing hub P may be connected to an antenna K which may be used as part of the system and method of the present invention to send alert information to any subscriber, as described in more detail below. Generally, antenna K would be cover some portion of a region of interest to subscribers, coincident with the area which the receivers R1, R2, R3, R4, R5, R6, R7, R8 collect location signal information in order to detect areas T or T2 identified as having anomalous GNSS signals, and in fact could be integrated into some or all of those receivers R1, R2, R3, R4, R5, R6, R7, R8 to provide maximum coverage for the sending and receiving of alerts.

[0099] Figure 7 is a flowchart illustrating an initial method by which the system and method of the present invention uses threshold T to determine if a particular location reported by a vessel is reporting GNSS location signals which can be considered to be accurate. First, from database DB a known location of the vessel which previous calculations have determined to have accurate GNSS location signals is retrieved. Next, current location data for that vessel, both from the GNSS navigation system and a non-GNSS navigation system are retrieved from the any one of, or multiple of, receivers R1, R2, R3, R4, R5, R6, R7, R8.

[0100] The two current location signals are then compared to one another, and a calculation is made (using known mathematical algorithms) to determine either the vector V between the two locations, or the angle θ and distance D between those two locations. Those calculated values are then compared against a pre-established or preset threshold T. Next, a determination is made as to whether to assign the vessel for which current location data has been collected to either 'active' or 'inactive' status. If the vessel reports location data below threshold T and also location data that is consistently at or near the same location, the vessel may be assigned the status of 'inactive' as being not currently navigated. It is also possible for this step to also include a calculation such that 'inactive' status is only assigned to vessels that both report locations below threshold T, which report several sequential location data values that are in the same location or within threshold T of the same location and which are within certain zones that are the known locations of harbours, dry docks or airfields, so that 'inactive' status may not be assigned to, for example, a vessel that is anchored at sea or maintaining a stationary position at sea.

[0101] The threshold T is a value determined to be small enough to encompass location data from different navigation systems that may have inherent differences in reporting but which is generally considered to be within a margin of error of those two locations such that they should generally considered to be the same. If the two locations are above the threshold T, the two signals are considered to be not the same, and thus the GNSS reported location is, at least temporarily, considered to be anomalous and potentially subject to spoofing or jamming. If the location data is below the threshold T, the same process steps are repeated a preset number n of times; if through all n number of the process steps in Figure 7 the locations are consistently below the threshold T then that particular vesselis considered to be reporting accurate GNSS location data, and the reported locations are stored in the database DB as being considered to be reliable. The same process is continued until such time as location data exceeds the threshold T, at which point the process steps of Figure 8 are followed. The periodicity of the process steps of Figure 7 is generally set to be longer than the periodicity of the process steps of Figure 8. This is because when a vessel is reporting a location that is at least temporarily considered to be reliable, it is less important to have rapid updating of location data retrieval from that vessel. So, for example, the process steps of Figure 7 may be conducted every 1 minute, whereas the process steps of Figure 8 may be conducted every 10 seconds.

[0102] Figure 8 is a flow chart showing how the system and method of the present invention calculates when location data from any particular vessel should be determined to be 'unreliable' or to be 'partially reliable,' and in the case of the latter, how the degree of partial reliability is determined. First, the current value of vector V or angle θ and distance D is compared against threshold T2. If that value is greater than the threshold T2 then the particular GNSS location corresponding to that value is determined to be 'unreliable' as it falls outside of the threshold for partial reliability established by threshold T2. If instead, the value is determined to be between the reliability threshold T and the unreliability threshold T2, then a calculation is done by the processing hub to assign a percentage to that value, the percentage being a reflection of where between the two thresholds the value lies. That calculated percentage is assigned as the 'partially reliable' weight W of that value. All of the calculated values and data integrity calculations are then stored in database DB.

[0103] Figure 9 is a flowchart showing how the processing hub P of the system and method of the present invention calculates the location C and areas D and E of unreliability and partial reliability are determined and stored using data from a large number of vessels. The receivers R1, R2, R3, R4, R5, R6, R7, R8 collect data from a large number of vessels, which data includes identifying information about the vessel plus GNSS and non-GNSS location data. As discussed above, various calculations are done to determine whether each of the GNSS reported locations of those vessels can be considered 'reliable, 'partially reliable, or 'unreliable.' The system then uses all of that data, and the calculated values assigned to a particular vessel, to determine both the possible location C of any spoofer or jammer, and the areas D and E (depending upon whether a particular subscriber is interested only in 'do not rely' areas D or 'do not rely' and 'partially reliable' areas D and E. Known calculation techniques for extracting a centerpoint of a large number of point locations (corresponding to the vessels reporting 'do not rely' GNSS locations and those reporting 'partially reliable' GNSS locations may be used to determine the location C where any spoofer or jammer may be located. Other known calculation techniques, again relying on the reported locations of the 'do not rely' vessel locations and 'partially reliable' vessel locations, and their weights W, may be used to calculate the areas D and E. All of that calculated information is then stored in the database

[0104] DB.

[0105] Figure 10 is a representation of a receiver unit RU that may be used by a subscriber of the system and method of the present invention. The system and method of the present invention need not include a receiver unit RU in all, or any, of the vessels which are subscribers, and in its simplest instantiation the system and method of the present invention merely relays information about areas of anomalous GNSS data to an air traffic control center, harbor pilot, coast guard, or other navigational authority, who may then use conventional communication systems to report to subscriber (or any) vessel information concerning anomalous GNSS signals, including location and area. Nevertheless, in a more sophisticated and automatized embodiment of the present invention, the receiver unit RU could be a dedicated device installed in the vessel of the subscriber specifically for the system and method of the present invention, or could be an existing navigational system which is adapted, using dedicated software and possibly a dedicated antenna, to implement the system and method of the present invention within that navigational system. The receiver unit RU would typically include at least three cables - power 1, local electronics bus 2, and antenna bus 3. Power cable 1 would be connected to the on-board power system to provide power to the receiver unit RU. Local electronics bus 2 would connect the receiver unit RU to existing electronics systems (for example, in an aircraft, to the on-board avionics system, or in a marine vessel an existing navigational system) on the vessel. Antenna bus 3 would connect to an antenna used to receive signals from antenna K so as to supply alerts to the subscriber. The alerts can take one or, or combinations of, many different forms, including a flashing light 4 (alone, or accompanied by an audio signal), a textual warning 5, or in more advanced systems, a navigational map 6 upon which the location C and calculated areas of affected areas T, T2 are displayed. In the event that there is an existing navigation system in the subscriber's vessel, the local electronics bus can send signals that include the information on the location C and calculated areas of affected areas T, T2, and electronics in the unit (or software installed on the subscriber's existing navigational system) can be used to overlay visually the information about the location C and calculated areas of affected areas T, T2 on the display of the subscriber's existing navigational system's display.

[0106] Figure 11 is a representation of an embodiment of the present invention that uses a stored database DB which may be accessed by the processing hub P in order to more discretely process information from the system and method of the present invention to better serve different subscribers based on their customer level as well as to better interpret and analyze information from the system itself. The database DB may contain information such as:

[0107] • The unique vessel ID for every vessel monitored by the system and method of the present invention.

[0108] • The location and extent of any 'inactive' areas, such as harbours, dry docks or airfields, where vessel location information should generally not be monitored frequently under the assumption that any vessels in that location are not actively navigating.

[0109] • The last known 'good' location of each monitored vessel, i.e., the last recorded location for that vessel outside of an 'inactive' area where the non-GNSS and GNSS location data was less than or equal to threshold T.

[0110] • The last known n number of reported GNSS locations data for the vessel, where 'n' is a preset number of recorded location data sufficient to extract usable information about the vessel's navigation and location and sufficient also to extract reliable comparative information of GNSS reported locations against non-GNSS reported locations.

[0111] The last known n number of reported non-GNSS locations data for the vessel, where 'n' is a preset number of recorded location data sufficient to extract usable information about the vessel's navigation and location and sufficient also to extract reliable comparative information of non-GNSS reported locations against GNSS reported locations.

[0112] • Last calculated n vectors V or last calculated n angles θ and distances D for the vessel based on the n location data values for GNSS and non-GNSS collected above.

[0113] • Threshold value T & threshold value T2, to set the outer boundaries of 'reliable' and 'unreliable' GNSS data signals in comparison to non-GNSS data signals.

[0114] • Last n calculated weighting values W for the vessel, for any location data for which any of the n vectors V or n angles θ and distances D are greater than T and less than T2.

[0115] • Subscription status for all vessels, i.e., is the particular monitored vessel a subscriber to the system and method of the present invention, and what sort of data is provided from the system and method of the present invention to that subscriber in the form of alerts or location and area information about zones Z1 or Z2.

[0116] The database DB is constantly updated with information collected by the receivers R1, R2, R3, R4, R5, R6, R7, R8 and by information calculated by the processing hub P. Information from database DB is also sent via global network GN (as well as information from other databases DB from other processing hubs P at other regional locations) and processed by global processing hub GP and stored within global database GDB.

[0117] Figure 12 is a representation of an embodiment of the present invention that uses a stored global database GDB which may be accessed by the global processing hub GP in order to more process information from the global network GN in the system and method of the present invention to store, process, and analyze global information from the regional processing hubs P so as to better predict and provide more accurate information about the location C and areas D and E in circumstances where the regional processing hub may not have sufficient vessel data to provide an accurate representation of that data. The global database GDB may contain information such as: The unique vessel ID for every vessel monitored by the system and method of the present invention throughout the globe.

[0118] • All historical location data, GNSS & non-GNSS, for every vessel in the global database GBD

[0119] • All historical vectors V or angles θ and distances D for every vessel in the global database GBD

[0120] • All historical velocity data for for every vessel in the global database GBD

[0121] • All historical weighting values W for every vessel in the global database GBD

[0122] • All historical subscription status for every vessel in the global database GBD

[0123] • All historical spoofing / jamming locations C calculated by every regional processing hub P

[0124] • All historical spoofing / jamming areas D & E calculated by every regional processing hub P

[0125] The global database GDB is constantly updated with information sent over global network GN from all of the regional processing hubs P throughout the system and method of the present invention.

[0126] Global processing hub GP includes, or is in connection with, an artificial intelligence or machine learning system AI / ML. The AI / ML system is used to extract information from the global database GDB and to train on that data in order to extract trends from the data in that database, so as to make predictions in the future of spoofing or jamming events, or to provide better information and prediction of locations C of spoofing or jamming activity, and the areas D and E that may be effected by spoofing or jamming, when - for example - there are few vessels reporting location information, and thus the regional processing hub P may have insufficient information to provide accurate information about location C or areas D and E. The artificial intelligence or machine learning system AI / ML may use all the historical data in global database GDB to extract information as to the locations C and areas D and E from massive amounts of historical location data and previous calculation of those areas, and these prior calculations based on historical data may be used to create predictive algorithms which may in turn be used to calculate future locations C and areas D and E based upon much smaller datasets from reported vessel locations reported to receivers R1, R2, R3, R4, R5, R6, R7, R8 and processed by a regional processing hub P. Thus, for example, a remote area in which there are only a handful of vessels currently navigating through that area may only therefore have 2 or 3 vessels which are reporting GNSS and non-GNSS location data, which may not normally be sufficient to provide a reasonably accurate assessment of the location C where spoofing or jamming activity is occurring, and the extent of areas D and E where GNSS location signals may be considered to be unreliable or partially reliable. Global processing hub GP, working with algorithms extracted from all historical data in global database GDB, could take the location data of those 2 or 3 vessels, processes all information (including locations, vectors, angles and distances, as well as velocities) in light of the closest historical information to that data and the resulting historical calculations of C, D, and E, and return predictive calculations of current values of C, D, and E that could provide a quite better estimate of those values based on the small dataset of current location values.

[0127] Note that the description above of an artificial intelligence / machine learning system AI / ML could also be instantiated at the regional level at the regional processing hub P and regional database DB, in instances where that processing hub and that database collect and store large amounts of location and other data about vessels that have sent location and other data via receivers R1, R2, R3, R4, R5, R6, R7, R8. Thus, a regional processing hub could extract a regional algorithm and directly apply it to location data incoming without having to have the global processing hub GP do the calculation or use data from outside the region. Note also that both the global and regional processing hubs GP and P could exchange data and algorithms so that each could update their own datasets and their own algorithms so that they can benefit from one another, and the global processing hub can also supplement regional calculations and algorithmic approximations in circumstances where vessels bridge the area between different regions covered by different processing hubs.

[0128] In GNSS navigation systems, each satellite broadcasts the same information to all users, in a given signal. The messages in the signal repeat every 22.5 minutes, so it is a straightforward exercise to compare the message (subframe) transmitted at t0, even though it is received at slightly different times due to the varied distance from each satellite to the receivers, and from the receivers to the processing hub. A simple binary comparison of each 3OO-bit subframe is sufficient to detect which receivers are receiving an altered message.

[0129] The correct information may then be transmitted to a vessel so that the vessel can take mitigation steps to prevent mis-navigation.

[0130] A vessel utilizing GNSS navigation may use multiple constellations to calculate its position; it just needs to know the inter-constellation time offsets as well as the different reference systems.

[0131] The GNSS navigation system for any vessel typically has a relatively cheap and simple clock on board. Only larger and more expensive reference receivers may connect to an atomic clock which is of comparable quality to the GNSS satellite’s on-board atomic clock. Therefore, it is customary for the navigation system used by the vessel to use its own clock only for the very coarse portion of signal acquisition, and then trusts the atomic clocks of the four or more satellites it is receiving in order to do GNSS location identification. The navigation system used by a vessel may even reset its own internal clock to match the received time from the more accurate clocks on the satellites S1, S2, S3, S4. If a spoofer or jammer S / J1 or S / J2 is broadcasting a wrong clock signal this can affect the vessel’s system and possibly cause that system to reset its own clock to an inaccurate time. For instance, some software systems require a check against GNSS time to determine whether the license to that software is valid and the vessel may intentionally spoof the clock to keep the software running when the license has actually expired. The present invention could be used by the vendor of that software to ensure the vessel is not self-spoofing its own system in order to circumvent restrictions on the time period for using that software, by detecting self-spoofing by a user and disabling the software that relies upon a GNSS clock in order to keep the software license valid.

[0132] Figure 13 is a flow chart showing the manner in which the system and method of the present invention using the detection of an alert condition in order to invoke an alternative navigation system by a vessel. As discussed above, the system and method of the present invention is designed to determine when an alarm condition exists, and transmits information to the vessel about that alarm condition and information that may be used in order to take actions in response to that alarm condition. When an alarm condition is transmitted to a vessel, the receiving unit RU is configured to determine if there is a secondary, alternative navigation system on-board, such as AIS or ADB-S navigation systems. If there is no such secondary, alternative navigation system on-board, the alarm condition signal triggers disablement of the primary GNSS navigation system and alert the captain, pilot or navigator that the vessel is no longer using primary navigation and therefore must be manually navigated, or (if possible) the vessel should be stopped until the alarm condition is no longer operative. If there is a secondary, alternative navigation system on-board, the receiving unit RU initiates operation of that system. The secondary, alternative navigation system then determines whether there are sufficient external signals to use the secondary, alternative navigation system, then that system is used to navigate that vessel. If there are not sufficient external signals to navigate using that secondary, alternative navigation system, then that system is not initiated as the navigation system, and manual navigation, or (if possible) stopping the vessel until the alarm condition is no longer operative is invoked.

[0133] Figures 14 and 15 are a flow charts showing the manner in which a backup, non-GNSS navigation system is initiated, and continues to be monitored until it is determined that the backup system does not need to be used. This case requires that vessel frequently submits their location to the system and method of the present invention via bi-directional signals between the vessel and the antenna K. When the system of the prior flow charts determines that there is area zone Z1 or Z2 subject to incorrect or incomplete GNSS navigation signals, a signal is sent to the vessel, including at least three forms of data: 1) an alarm signal ("spoofing / jamming ongoing"), which triggers an alarm for the captain, pilot or navigator to be alerted that the GNSS system is being disabled and that a backup navigation system is being initiated, 2) a disabling signal for the GNSS navigation system, and 3) an enabling signal to initiate the backup, non-GNSS, navigation system (or, as described in the previous Figure, when the back-up non-GNSS navigation system is unavailable, toggles navigation to manual navigation or - if possible - stops the vessel from further movement). The system continuously recalculates whether the zones Z1 and Z2 is subject to spoofing and / or jamming by spoofer or jammer S / J1 or S / J2, and, via signal from a vessel to antenna K, whether the vessel remains in that zone. If both conditions are met, the alarm signal continues, as does the signal disabling the GNSS navigation system and enabling the non-GNSS navigation system. If either of those conditions are not met - either the vessel is outside of zones Z1 or Z2, or the spoofing or jamming in zone Z1 or Z2 is no longer occurring, then the alarm signal is turned off and the alarm no longer signals, and the navigation system is toggled back from non-GNSS to GNSS. The signals back and forth between antenna K and a vessel are continuously refreshed with new information to communicate the size and location of zones Z1 and Z2 and the location of a vessel relative that those areas Z1 and Z2. Once a vessel is outside of zones Z1 and Z2, the alarm signal is stopped and a "clear" signal is sent - and the captain, pilot or navigator is alerted that primary navigation is being reinitiated - the GNSS navigation system is reinitiated, and the backup navigation system is disabled.

[0134] If a vessel is not providing a signal from the vessel to antenna K with information on vessel's current position (either because the vessel does not have transmission capability, or that transmission capability is disabled or inoperative), then the system and method of the present invention cannot dynamically update so as to toggle off the alarm signal and to toggle back on the primary GNSS navigation system; in that case, the vessel must make the decision locally by monitoring its own position and manually disabling the alarm signal and toggling on the primary GNSS navigation system.

[0135] In the invention of Fig. 11-15, the receiving unit RU is designed to receive signals both from a GNSS navigation system and a non-GNSS navigation system. These signals are transmitted over antenna bus 3, as are signals from the antenna K which send both an alarm signal when it is determined that vessel is at or near an zones Z1 or Z2 subject to spoofing or jamming, and a signal which toggles the navigation system from GNSS navigation and non-GNSS navigation, depending on whether the vessel remains in zones Z1 or Z2 and whether the GNSS signals in zones Z1 or Z2 continue to be compromised.

[0136] As described in more detail above, in the system and method of the present invention, a network of receivers are positioned (if not already positioned) in key locations in vicinities which have a risk of GNSS interference to detect non-GNSS location information, which receivers supplement an existing overlay network of detectors for location information like AIS and / or ADS-B. The system and method of the present invention includes a processing hub or hubs with artificial intelligence and / or machine learning capabilities, which will correlate data based on a complex levels-of-trust concepts.

[0137] In the system and method of the present invention, there are multiple geographically distributed networks of sensor stations, which sensor stations are designed to receive navigation data from one or more non-GNSS navigation signals (such as ADS-B and / or AIS) broadcast from vessels within transmission range of the sensors. Many of these sensor networks are in signal connection with a global processing hub GP, which global processing hub GP aggregates collected information from the many processing hubs P located around the globe to receive and initially process location information to discern its accuracy and also to calculate the location C of potential spoofing or jamming as well as areas D and E that can be considered as either having 'unreliable' or 'partially reliable' GNSS location data. Because the networks are physically distributed and because there are multiple networks, absent mitigation, there is a risk that some nodes within a network, or an individual network within an aggregation of networks may serve incorrect data to the processing hub P. The data served to the processing hub P can be incorrect because some of the receivers R1, R2, R3, R4, R5, R6, R7, R8 are not calibrated, or otherwise inadequately maintained, or because incorrect or misleading data has been inserted, whether accidentally or intentionally.

[0138] As a result of the problem of potential incorrect data, the aggregrating node where a processing hub P processes information for a region comprised of a particular set of receivers R1, R2, R3, R4, R5, R6, R7, R8, any aggregating node - including a global node with a global processing hub GP that aggregates data from subnodes represented by a disaggregated series of regional processing hubs P - needs a way to identify and characterize the nodes and networks with questionable quality of location data. Although a brute-force approach to only use data from qualified receivers R1, R2, R3, R4, R5, R6, R7, R8 or qualified processing hubs P as a mechanism to ensure data quality could be employed, doing so potentially leaves valuable data 'on the ground' or discarded, and fails to recognize a 'shades of grey' reality where some nodes or networks may be 'mostly' reliable and some node or networks may be 'totally reliable' and other nodes or networks may be consistently unreliable, but nevertheless offer up some data that may be useful. The system and method of the present invention may receive data from multiple networks (represented either by network N for receivers R1, R2, R3, R4, R5, R6, R7, R8 or global network GN for processing hubs P), and each network may be assigned a historical level of trust; in turn individual receivers R1, R2, R3, R4, R5, R6, R7, R8 in each individual network N, or individual processing hubs P in the global network GN, are also assigned a historical level of trust. Data integrity can be weighted based on these layers of historical levels of trust. Because the integrity of data can change rapidly as - for instance - a hostile actor inserts their own data in a stream into an individual receiver or processing hub, these hostile actions must be detected quickly and the trust-weighting changed for at least the duration of the event during which hostile data is being inserted.

[0139] Figure 16 illustrates the manner in which nodes and networks according to the description above and below could be instantiated. A global processing hub GP is connected by a global network GN to various regional processing hubs P1, P2. The global network itself has several nodes GO in-between the processing hubs P1, P2 and the global processing hub GP. The portions of the network that traverse those nodes themselves are of different physical distances. Similarly, each regional processing hub P1, P2 is in connection with various receivers (in Figure 16, regional processing hub P1 is in connection with receivers R6, R7 & R8 via network Nl, whereas regional processing hub P2 is in connection with receivers R2, R3, R4 & R5 via network N2), and those connections are via networks Nl and N2, respectively, each of which networks contain various nodes O. Each of the connections to a receiver within networks Nl and N2 are of various physical distances to the respective regional processing hub P1, P2.

[0140] In the system and method of the present invention, distance must be considered from two standpoints: physical distance between any particular receivers R1, R2, R3, R4, R5, R6, R7, R8 and the processing hub P to which that receiver is in signal connection via network N, as well as the number of intermediate nodes that the signal needs to traverse in order for the location signals to reach the processing hub P, e.g. how many VPN segments, how many NTRIP casters, etc., exist between the receiver and processing hub P. For instance if a virtual private network (VPN) exists between a receiver in Manhattan and a processing hub in Toronto, then the physical distance between receiver and processing hub P is 550 km, and the number of nodes traversed is 1. However, if the signal transmission between the Manhattan receiver and the Toronto processing hub P relies a third party in Chicago with two casters between the receiver and processing hub P, the physical distance is 700 km and the number of nodes traversed is 3.

[0141] In the system and method of the present invention, a signal integrity equation is used to calculate physical and nodal distance in order to arrive at a confidence level for any particular signal from a receiver:

[0142] C = f (d,n)

[0143] Where C is confidence, f a function to be determined, d is physical distance between receiver and processing hub P (as that distance is calculated as a result of routing to various nodes) and n is number of nodes between the receiver and the processing hub P.

[0144] To make decisions, the following formula may be used:

[0145] D = Σ (C) / Σ (n).

[0146] Where D is the decision to be made, calculated as a sum of all the confidence levels (C) for all nodes in the system, divided by the number (n) of nodes.

[0147] In the system and method of the present invention, the processing hub P, or in the case of a global system, the global processing hub GP, includes an artificial intelligence or machine learning system that is used to determine the function f. The function f is extracted by the artificial intelligence or machine learning system by training that system on a massive dataset of historical data for the values of physical distance d and number of nodes n for every signal received over a lengthy period of data sampling, as well as the past known outcomes. The validity of the model is confirmed with live data.

[0148] For a number of nodes 'n'

[0149] Output = function({inputn*weightn})

[0150] For example, there are three nodes, each has an assigned weight.

[0151] A particular vessel location is transmitted from each receiver.

[0152] A simple average across these three nodes would yield: (100+110+75) / 3 = 95.0. A weighted average across these three nodes would yield: (5*100+10*110+1*75) / (5+10+1) = 104.7. Thus the location, using this formula, would be set at 104.7 even though no individual receiver reported that exact location data. This averaging would ensure that individual anomalies at each individual receiver would be weighted and averaged to arrive at a location that best approximates the actual location given the distances and node numbers that the data must traverse to be received, processed, and stored by the processing hub P.

[0153] The function f can be an arbitrary mathematical function, and the number of nodes is flexible. This system and method of the present invention concerns itself primarily with the method of determining weights, doing so by using artificial intelligence or machine learning systems to calculate a function or function which can be used to assign weights to individual nodes.

[0154] Some nodes and / or networks can be highly trusted, if it is known they are secure and calibrated and in a location with a high likelihood that signal interference is not occurring, whereas other nodes and / or networks are of low or no trust, but that nevertheless their data signals may have some value to determining the overall integrity of GNSS signals in a particular vicinity. For nodes and / or networks with known high trust and high data integrity, higher weights would be assigned; conversely, for nodes and / or networks with known low (or unknown) trust and low (or unknown) data integrity, lower, or no weight, would be assigned. As more data is gathered, and more information is compiled about the integrity of nodes, networks, and / or data, the weights would be dynamically adjusted to create a dynamic picture at any particular time of the entire network, the level of trust of all data fed into the database system, and thus produce an up-to-date model of the entire system, the trust level of the inputs to the system, and whether GNSS signals throughout the system should be fully trusted, partially trusted, or not trusted at all.

[0155] The description and drawings describe but a few of the potential embodiments of the present invention. Although the embodiment described above are shown for air and marine vessels, the invention is equally adaptable and applicable to general transportation uses, such as railways, roads and highways or other forms of transport that may use GNSS for navigation. In addition, the system and method of the present invention may be adapted to improve the integrity of autonomous driving, flying, or sailing when GNSS location systems are an important part of a driverless, pilotless or navigator-less system.

[0156] Interested parties may subscribe to this system and receive alerts and updated and accurate location information in a secure manner. For instance, an airport authority may receive the alerts at the Air Traffic Control Centre (ATCC) and controllers can relay the information to nearby aircraft so that they can adjust their navigation system so as to navigate around, or rely on non-GNSS navigational systems, in areas where the system and method of the present invention determines the GNSS signals in that area have been identified as potentially false or jammed. Likewise, a shipping company could equip its vessels with alert receivers and internal systems to account for false or jammed signals in those areas. Alerts may be sent to subscribers via encoded radio message and / or via the internet, as long as these messages are made in a secure fashion so that they are also not subject to spoofing or jamming. The system should be designed to ensure that only messages relevant to a user are displayed. For instance, if there is a spoofing incident in one location - for example, Boston, Massachusetts, USA - a subscriber in Abu Dhabi wouldn't need to receive an alert, but a subscriber in Providence, Rhode Island, USA, might wish to receive an alert as the spoofing or jamming might equally affect some signals relied upon at that location or that user might be considering navigating toward the area identified as potentially subject to spoofing or jamming.

Claims

AMENDED CLAIMS received by the International Bureau on June 23, 2025 (23.06.2025)CLAIMS1. A system for detecting, locating, and reporting on anomalous navigation information, comprising: a plurality of earth-based receivers for receiving both GNSS and non-GNSS navigation data from at least one vessel; a processing hub in signal connection with the plurality of earth-based receivers; wherein the processing hub makes a comparison between the received GNSS navigation data and the non-GNSS navigation data and calculates a difference between the GNSS navigation data and the non-GNSS navigation data; and wherein the processing hub compares the calculated difference against an established threshold; and wherein if the calculated difference is found to be below the established threshold, the GNSS navigation data is determined to be reliable; and wherein if the calculated difference is found to be above the established threshold, the GNSS navigation data is determined to be unreliable; and wherein a location of the non-GNSS navigation data against which unreliable GNSS navigation data is correlated is reported as being a location wherein GNSS navigation data should be considered to be unreliable.

2. The system of claim 1, wherein: any GNSS navigation data determined to be unreliable is assigned a weight corresponding to a degree of confidence, the degree of confidence being determined based on the size of the calculated difference between the GNSS navigation data and the non-GNSS navigation data.

3. The system of claim 2, wherein: the system collects GNSS and non-GNSS navigation data from a plurality of vessels;and wherein the degree of confidence is calculated for GNSS navigation data for each of the plurality of vessels.

4. The system of claim 2, wherein: the degree of confidence for each of the plurality of vessels is used to establish an area where GNSS navigation data should considered unreliable.

5. The system of claim 3, further comprising: an artificial intelligence system; wherein the GNSS navigation data, the non-GNSS navigation data, and degrees of confidence are used to train the artificial intelligence system.

6. The system of claim 4, wherein: the system sends an alert to any vessel determined to be in the area where GNSS navigation should be considered unreliable.

7. The system of claim 1, further comprising: a database that stores the received GNSS navigation data, the received non-GNSS navigation data, and locations considered to be unreliable.

8. The system of claim 4, further comprising: a database that stores the received GNSS navigation data, the received non-GNSS navigation data, and areas considered to be unreliable.

9. A method for detecting, locating, and reporting on anomalous navigation information, comprising the steps of: receiving both GNSS and non-GNSS navigation data from at least one vessel; making a comparison between the received GNSS navigation data and the non-GNSS navigation data;calculating a difference between the GNSS navigation data and the non-GNSS navigation data; comparing the calculated difference against an established threshold; determining the GNSS navigation data to be reliable if the calculated difference is found to be below the established threshold; determining the GNSS navigation data to be unreliable if the calculated difference is found to be above the established threshold; and reporting a location of the non-GNSS navigation data against which unreliable GNSS navigation data is correlated as being a location wherein GNSS navigation data should be considered to be unreliable.

10. The method of claim 9, further comprising the step of: assigning a weight corresponding to a degree of confidence to any GNSS navigation data determined to be unreliable, the degree of confidence being determined based on the size of the calculated difference between the GNSS navigation data and the non-GNSS navigation data.

11. The method of claim 10, further comprising the step of: collecting GNSS and non-GNSS navigation data from a plurality of vessels; calculating the degree of confidence GNSS navigation data for each of the plurality of vessels.

12. The method of claim 11, further comprising the step of: using the degree of confidence for each of the plurality of vessels to establish an area where GNSS navigation data should considered unreliable.

13. The method of claim 11, wherein:training an artificial intelligence system using the GNSS navigation data, the non-GNSS navigation data, and degrees of confidence.

14. The method of claim 12, further comprising the step of: sending an alert to any vessel determined to be in the area where GNSS navigation should be considered unreliable.

15. The method of claim 14, further comprising the step of: storing GNSS navigation data, non-GNSS navigation data, and unreliable location data in a database.

16. A system for detecting, locating, and reporting on anomalous navigation information, comprising: a global processing hub; a plurality of regional processing hubs; a global network providing signal communication between the global processing hub and the plurality of regional processing hubs; a plurality receiving stations, the plurality of receiving stations receiving GNSS and non¬GNSS navigation data from a plurality of vessels; a plurality of regional networks providing signal communication between the plurality of receiving stations and the plurality of regional processing hubs, wherein the plurality of regional networks each contain at least one node through which signals are communicated to the plurality of regional processing hubs; wherein the plurality of regional processing hubs assign weights to signals from the plurality of receiving stations depending upon the number of nodes and a distance that the signal from a receiving station traverses to reach a regional processing hub.

17. The system of claim 16, wherein:the global network contains at least one node through which signals are communicated to the global processing hub; wherein the global processing hubs assigns weights to signals from the plurality of regional processing hubs depending upon the number of nodes and the distance that the signal from a regional processing hub traverses to reach a global processing hub.

18. The system of claim 17, further comprising: an artificial intelligence system in signal connection with the global processing hub; wherein the weights are used to train the artificial intelligence system.

19. The system of claim 18, wherein: a confidence level for any particular signal from a regional processing hub is calculated by the artificial intelligence system.

20. The system of claim 16, further comprising: a database that stores the received GNSS navigation data, the received non-GNSS navigation data, and the calculated weights.

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