Real-time kinematic (RTK) and differential Global Navigation Satellite System (DGNSS) correction using multiple reference stations

Abstract

A real-time kinematic (RTK) and / or differential GNSS (DGNSS) system is disclosed in which correction data from multiple reference stations is provided to a mobile device. Selection of the reference station (from which correction data is provided to the mobile device) may be based on factors such as the approximate location of the mobile device, the geometry of the reference station, and / or other factors. The mobile device can combine the correction data from the multiple reference stations in various ways to determine an accurate position fix for the mobile device without having to interpolate the correction data from the multiple reference stations.

Description

[Technical Field]

[0001] This invention generally relates to the field of satellite-based positioning, and more specifically to error correction of Global Navigation Satellite System (GNSS) terms for more accurate position determination. [Background technology]

[0002] Precise positioning services (PPS) provide extremely accurate meter-level or submeter-level positioning for mobile devices, exceeding the accuracy of conventional consumer-grade Global Navigation Satellite System (GNSS) receivers. PPS includes services such as precise point positioning (PPP), real-time kinematic (RTK), and differential GNSS (DGNSS). These services often perform network-based interpolation of reference station data to provide correction data (e.g., reference measurements) to the mobile station for positioning, resulting in varying degrees of accuracy, availability, and reliability. For extremely accurate positioning of mobile devices, conventional PPS can take a relatively long time (e.g., several minutes or more). Many conventional applications, such as land surveying, may not require faster positioning. However, PPS can be useful in various modern applications when it can provide relatively fast, extremely accurate positioning. [Overview of the project] [Means for solving the problem]

[0003] The embodiments described below in this specification address these and other issues by providing an RTK / DGNSS system that provides correction data from multiple reference stations to a mobile device. In detail, the selection of a reference station may be based on factors such as the approximate location of the mobile device, the geometry of the reference station, and / or other factors. The mobile device can combine the correction data from multiple reference stations in any of the following ways to determine the precise position fix for the mobile device. The selection of a reference station may be performed by a service provider that is communicatively coupled to the mobile device via any combination of public and / or private networks.

[0004] An exemplary method provided herein for providing reference station correction data to a mobile device for real-time kinematic (RTK) or differential global navigation satellite system (DGNSS) correction comprises receiving information indicating the approximate location of the mobile device or information about satellite vehicles visible to the mobile device. The method also comprises selecting a plurality of reference stations from which reference station correction data should be obtained, wherein the selection is at least in part based on the approximate location of the mobile device or information about satellite vehicles visible to the mobile device. The method also comprises obtaining reference station correction data from each of the plurality of reference stations, wherein for each reference station, the reference station correction data may comprise data based on one or more measurements obtained by a GNSS receiver at the respective reference station. The method also comprises sending the reference station correction data to the mobile device.

[0005] An exemplary method for applying real-time kinematic (RTK) or differential Global Navigation Satellite System (DGNSS) corrections in a mobile device, as disclosed herein, comprises the steps of acquiring base station correction data in the mobile device from each of a plurality of base stations, wherein for each base station, the base station correction data may comprise one or more measurements obtained by a GNSS receiver at each base station. The method also comprises the steps of acquiring mobile device measurement data, wherein the mobile device measurement data may comprise one or more measurements obtained by a GNSS receiver at the mobile device. The method also comprises the steps of determining the position of the mobile device based on the base station correction data from each of the plurality of base stations and the mobile device measurement data.

[0006] An exemplary computer server for providing reference station correction data to a mobile device for real-time kinematic (RTK) or differential Global Navigation Satellite System (DGNSS) correction, as disclosed herein, comprises a transceiver, memory, and one or more processing units communicatively coupled to the transceiver and memory. One or more processing units are configured to receive information indicating the approximate location of the mobile device or information about satellite vehicles visible to the mobile device. One or more processing units are further configured to select a plurality of reference stations from which reference station correction data should be obtained, wherein the selection is at least in part based on the approximate location of the mobile device or information about satellite vehicles visible to the mobile device. One or more processing units are further configured to obtain reference station correction data from each of the plurality of reference stations, wherein for each reference station, the reference station correction data may comprise data based on one or more measurements obtained by a GNSS receiver at the respective reference station. One or more processing units are further configured to send the reference station correction data to the mobile device via the transceiver.

[0007] An exemplary mobile device for applying real-time kinematic (RTK) or differential Global Navigation Satellite System (DGNSS) corrections as disclosed herein comprises a transceiver, a GNSS receiver, memory, and one or more processing units communicatively coupled to the transceiver, GNSS receiver, and memory. The one or more processing units are configured to acquire base station correction data via the transceiver from each of a plurality of base stations, wherein for each base station, the base station correction data may comprise one or more measurements obtained by the GNSS receiver at each base station. The one or more processing units are also configured to acquire mobile device measurement data, wherein the mobile device measurement data may comprise one or more measurements obtained by the GNSS receiver of the mobile device. The one or more processing units are also configured to determine the position of the mobile device based on the base station correction data from each of the plurality of base stations and the mobile device measurement data.

[0008] An exemplary device for providing a reference station correction data to a mobile device for real-time kinematic (RTK) or differential global navigation satellite system (DGNSS) correction, as disclosed herein, comprises means for receiving information indicating the approximate location of the mobile device or information about satellite vehicles visible to the mobile device. The device also comprises means for selecting a plurality of reference stations from which reference station correction data should be obtained, wherein the selection is at least in part based on the approximate location of the mobile device or information about satellite vehicles visible to the mobile device. The device also comprises means for obtaining reference station correction data from each of the plurality of reference stations, wherein for each reference station, the reference station correction data may comprise data based on one or more measurements obtained by a GNSS receiver at the respective reference station. The device also comprises means for sending the reference station correction data to the mobile device.

[0009] An exemplary device for applying real-time kinematic (RTK) or differential Global Navigation Satellite System (DGNSS) corrections in a mobile device, as disclosed herein, comprises means for acquiring base station correction data in the mobile device from each of a plurality of base stations, wherein for each base station, the base station correction data may comprise one or more measurements obtained by a GNSS receiver at each base station. The device also comprises means for acquiring mobile device measurement data, wherein the mobile device measurement data may comprise one or more measurements obtained by a GNSS receiver at the mobile device. The device also comprises means for determining the position of the mobile device based on the base station correction data from each of the plurality of base stations and the mobile device measurement data.

[0010] An exemplary non-transient computer-readable medium provided herein stores instructions for providing a mobile device with reference station correction data for real-time kinematic (RTK) or differential Global Navigation Satellite System (DGNSS) correction. The instructions include a code for receiving information indicating the approximate location of the mobile device or information about satellite vehicles visible to the mobile device. The instructions also include a code for selecting a plurality of reference stations from which reference station correction data should be obtained, wherein the selection is at least in part based on the approximate location of the mobile device or information about satellite vehicles visible to the mobile device. The instructions also include a code for obtaining reference station correction data from each of the plurality of reference stations, wherein for each reference station, the reference station correction data may include data based on one or more measurements obtained by a GNSS receiver at the respective reference station. The instructions also include a code for sending the reference station correction data to the mobile device.

[0011] The exemplary non-transient computer-readable medium described herein stores instructions for applying real-time kinematic (RTK) or differential Global Navigation Satellite System (DGNSS) corrections to a mobile device. The instructions include a code for obtaining base station correction data from each of a plurality of base stations in the mobile device, wherein for each base station, the base station correction data may include one or more measurements obtained by a GNSS receiver at each base station. The instructions also include a code for obtaining mobile device measurement data, wherein the mobile device measurement data may include one or more measurements obtained by a GNSS receiver at the mobile device. The instructions also include a code for determining the position of the mobile device based on the base station correction data from each of the plurality of base stations and the mobile device measurement data. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic diagram of a real-time kinematic (RTK) and differential GNSS (DGNSS) system according to one embodiment. [Figure 2] This diagram shows an overhead view of a mobile device and multiple base stations, illustrating algorithms that may be used for base station selection in several embodiments. [Figure 3] This diagram shows an overhead view of a mobile device and multiple base stations, illustrating algorithms that may be used for base station selection in several embodiments. [Figure 4] This is an exemplary sky plot illustrating the azimuths and altitudes of various satellites that can be observed by base stations R1 and R2. [Figure 5] This is a schematic diagram illustrating, according to one embodiment, how data from various reference stations can be provided to various mobile devices based on the location of each mobile device within an area serviced by a mobile carrier network. [Figure 6]This is a timing diagram of various scheduling methods according to one embodiment. [Figure 7] This diagram shows an overhead view of a mobile device and multiple reference stations, illustrating values ​​that can be derived from reference station correction data and used to perform data integrity checks, according to one embodiment. [Figure 8] This diagram shows an overhead view of a mobile device and multiple reference stations, illustrating values ​​that can be derived from reference station correction data and used to perform data integrity checks, according to one embodiment. [Figure 9A] This is a flowchart illustrating various embodiments of methods for providing base station correction data to a mobile device for RTK or DGNSS correction. [Figure 9B] This is a flowchart illustrating various embodiments of methods for providing base station correction data to a mobile device for RTK or DGNSS correction. [Figure 10A] This is a flowchart illustrating various embodiments of methods for applying RTK or DGNSS correction to mobile devices. [Figure 10B] This is a flowchart illustrating various embodiments of methods for applying RTK or DGNSS correction to mobile devices. [Figure 10C] This is a flowchart illustrating various embodiments of methods for applying RTK or DGNSS correction to mobile devices. [Figure 11] This is a block diagram of a mobile device according to one embodiment. [Figure 12] This is a block diagram of one embodiment of a computer system. [Modes for carrying out the invention]

[0013] According to some exemplary implementations, like reference numerals in various drawings indicate like elements. In addition, multiple instances of an element may be indicated by following the first numeral for the element with a letter or a hyphen and a second numeral. For example, multiple instances of element 110 may be shown as 110-1, 110-2, 110-3, etc., or 110a, 110b, 110c, etc. When referring to such an element using only the first numeral, any instance of that element should be understood (for example, element 110 in the preceding example refers to elements 110-1, 110-2, and 110-3, or elements 110a, 110b, and 110c).

[0014] Some exemplary embodiments will now be described with reference to the accompanying drawings, which form a part of the present specification. Although specific embodiments in which one or more aspects of the present disclosure may be implemented are described below, other embodiments may be used and various modifications may be made without departing from the scope of the present disclosure.

[0015] As used herein, the terms "position" and "location" are used interchangeably. Further, terms such as "position determination", "position fix", "position estimate", "estimated position", and "location fix" are also used interchangeably herein with respect to GNSS-based positioning to refer to an estimated position of a mobile device or other device comprising a GNSS receiver. A position or location may be, for example, a two-dimensional position with respect to a two-dimensional map, or a three-dimensional position.

[0016] Additionally, as used herein, the term “correction data” may refer to correction information provided by an RTK service provided to enable high-accuracy position determination of a device having a GNSS receiver. Correction data may include measurement data acquired by a reference station, and / or correction information derived from measurement data, such as the difference between a true distance determination based on the known position of the reference station and the measurement obtained at the reference station. To determine the high-accuracy position of a device, correction data may be used together with measurement obtained at the device having a GNSS receiver, as described herein.

[0017] Figure 1 is a schematic diagram of a real-time kinematic (RTK) and differential GNSS (DGNSS) system according to one embodiment. The RTK / DGNSS system 100 enables extremely accurate (e.g., sub-meter) GNSS position fixing of a mobile device 110 (also called a "rover station" or "rover") by using GNSS receivers in both the mobile device 110 and one or more reference stations 120 (also called "base stations") that receive radio frequency (RF) signals 130 from satellite vehicles (SVs) 140 (GNSS satellites) from one or more GNSS constellations (e.g., Global Positioning System (GPS), Galileo (GAL), Global Navigation Satellite System (GLONASS), Beidou, etc.). The type of mobile device 110 used may vary depending on the application and may include any of the various types of devices that have access to GNSS positioning data, such as a mobile device equipped with a GNSS receiver. Such mobile devices may include consumer electronics or other mobile consumer devices, such as mobile phones, tablets, laptops, wearable devices, and vehicles. In some embodiments, the mobile device 110 may include industrial equipment such as surveying equipment.

[0018] In GNSS-based positioning, the mobile device 110 can determine the distance to each SV140 based on a determined delay of a generated pseudo-random binary sequence received in the RF signal 130, using code-based positioning. The mobile device 110 can further calculate the position of each SV140 at a specific moment in time using ephemeris (or navigation) data related to the SV140. Using the distance and position information of the SV140, the mobile device 110 can then determine a position fix for that position using conventional GNSS techniques. This position fix may be determined, for example, by a Standalone Positioning Engine (SPE) run by one or more processors in the mobile device 110. However, the accuracy of the position fix obtained for the mobile device 110 is susceptible to errors caused by the SV140 orbit and clock, ionospheric and tropospheric delays, and other phenomena. This can result in meter-magnitude accuracy, but this accuracy may be insufficient for many applications.

[0019] DGNSS provides an extension to conventional GNSS positioning by providing correction data from a reference station 120 having a known fixed location. More specifically, the reference station 120 obtains GNSS measurements of an RF signal 130 using a highly accurate GNSS receiver, and such GNSS measurements are provided to the mobile device 110 (e.g., via radio broadcast and / or a data communication network 150 such as the Internet) along with the known location of the reference station 120. The mobile device can then extend GNSS-based positioning by using the correction data (which may include the measurement data and location information of the reference station 120, or correction information derived therefrom) to correct the measured distance (pseudo-distance) to each of the SV 140s. This more precise position fix may be determined, for example, by a Precise Positioning Engine (PPE) run by one or more processors in the mobile device 110.

[0020] RTK positioning can provide even more accurate solutions (e.g., centimeter or decimeter magnitude) by using carrier-based ranging based on the carrier of the RF signal 130. Similar to DGNSS, RTK positioning can use a base station 120 to measure the RF signal 130 from a known location using a highly accurate GNSS receiver. However, unlike DGNSS, RTK correction data (also called “RTK service data”) includes highly accurate carrier-based ranging. RTK correction data may be shared with a mobile device 110 via a radio broadcast and / or data communication network 150. The mobile device 110 can then use the RTK correction data to correct errors in its own carrier-based ranging using its own measurements of the RF signal 130 from its own GNSS receiver. Error correction for RTK positioning may include corrections for satellite clock and orbit, ionospheric and tropospheric delays, phase wind-up, solid Earth tides, ocean loads, and / or polar tides, including site displacement corrections. A more accurate position fix (i.e., position) may be determined, for example, by a PPE performed by one or more processors of the mobile device 110. More specifically, in addition to the information provided to the SPE, the PPE may use RTK correction data to provide a high-accuracy carrier-based position fix. Several GNSS techniques, such as DGNSS, RTK, and PPP, may be employed in the PPE.

[0021] The mobile device 110 can determine its position using a position estimator or positioning engine (e.g., PPE) that incorporates ambiguity resolution and differential correction. The position estimator may use estimation techniques such as using an Extended Kalman Filter (EKF), Weighted Least Squares (WLS), a hatch filter, or a particle filter. The accuracy of the position fix for the mobile device 110 may depend on its distance from the base station 120, i.e., the "baseline" 160, the accuracy of the differential correction, etc. Conventional DGNSS and RTK corrections are limited to baselines 160 of several kilometers or tens of kilometers magnitude, but the new technique may extend the baseline 160 to much longer distances using extended techniques for error correction. For example, Ultra-Long Baseline RTK (ULB-RTK) can use a multi-constellation, multi-frequency (MCMF) GNSS receiver and tropospheric modeling in the mobile device 110 to perform corrections for errors caused by ionospheric and tropospheric delays, enabling baselines 160 of up to 1000 km or more. Due to this increased distance, there may be fewer SV140 observable by both the mobile device 110 and the reference station 120. These SV140 are referred to herein as “Common View Satellites”.

[0022] DGNSS and RTK positioning can be further extended using network-based techniques. In network-based DGNSS / RTK, correction data from multiple base stations 120 is sent to a service provider 170. A mobile device 110 can then receive DGNSS / RTK correction data on demand by sending a request to the service provider 170 that includes the approximate location of the mobile device 110 (for example, based on a previously known position, non-GNSS-based positioning such as a tracking area in a wireless communication network, or dead reckoning-based positioning of a vehicle). The service provider 170, which may comprise one or more computer servers, can then provide customized DGNSS / RTK service data to the mobile device 110 by interpolating the correction data from the multiple base stations 120 to provide DGNSS / RTK service data for the approximate location of the mobile device 110. To interpolate the correction data, the service provider 170 may execute an elaborate GNSS algorithm based on the geometry of the base stations 120 used. Due to the sophistication of the interpolated solution, the convergence time (the length of time required to obtain a highly accurate position determination) can be relatively long. As mentioned earlier, this is not a problem in applications where a relatively long convergence time is acceptable (e.g., land surveying), but it can be a problem in other applications where time and safety may be critical (e.g., autonomous driving).

[0023] The embodiments described below in this specification address these and other issues by providing an RTK / DGNSS system 100 in which single-base station-based DGNSS / RTK service data (also referred to herein as base station correction data) from each of a plurality of base stations 120 is provided to a mobile device 110. In some embodiments, such DGNSS / RTK service data based on or related to a single base station may be uninterpolated DGNSS / RTK service data. As will be described in more detail below, the selection of a base station 120 may be based on factors such as the approximate location of the mobile device, the geometry of the base station 120, and / or other factors. Additionally, and as will be described in more detail below, the mobile device 110 can combine correction data from multiple base stations 120 in any of the following ways to determine an accurate position fix for the mobile device 110. The selection of a base station 120 may be performed by one or more computer servers (e.g., a service provider 170) that are communicably coupled to the base stations 120 and the mobile device 110 via a data communication network 150. As stated above, the data communications network 150 may comprise any of various public and / or private networks, which may include the Internet, one or more mobile carrier networks, and / or other such wide area networks (WANs).

[0024] As described above, two or more relevant reference stations 120 may be selected based on the approximate position of the mobile device, from which correction data may be provided to the mobile device 110. The number N of reference stations to which the server provides correction information may vary depending on the quality of service (QoS) or user requirements. N may be additional or alternative, specific to the application, and may be larger when higher accuracy, availability, and / or reliability are required, taking into account other limitations (e.g., the processing power of the mobile device 110). Figures 2 to 5 show algorithms that may be used for such reference station selection.

[0025] Figure 2 is an overhead view of the positions of four reference stations R1-R4 relative to the approximate mobile device location 210. The notation "R" used herein (e.g., R1-R4) may correspond to the position of a reference station (e.g., reference station 120 of the RTK / DGNSS system 100 as shown in Figure 1), and / or the reference station itself. The approximate mobile device location 210 may correspond to the location of a mobile device (e.g., mobile device 110) within the geographic area served by the RTK / DGNSS system 100.

[0026] The reference station selection method shown in Figure 2 is proximity-based. That is, reference stations may be selected based on their proximity to the approximate mobile device location 210. This may be determined using a radius 230, which can be used in various ways as illustrated. In some embodiments, for example, the reference station selection process may involve starting with a small radius 230 and increasing the size of the radius 230 until a desired number N reference stations fall within the area 240 covered by the radius 230. Additional or alternative techniques may be used to determine the number N reference stations closest to the approximate mobile device location 210. Alternatively, an embodiment may have a radius 230 of a predetermined length and select all reference stations that fall within the area 240 defined by the predetermined radius 230. Once reference stations are selected, correction data from the reference stations may be provided to the mobile device. In the example shown in Figure 2, reference stations R1-R3 fall within the area 240 defined by the radius 230 and are therefore selected. Reference station R4, on the other hand, is not selected.

[0027] As an alternative to radius-based techniques, embodiments may refer to stations based on geofencing or a predetermined area. For example, the geographic area served by the RTK / DGNSS system 100 service provider 170 may be divided into several predetermined areas, where each predetermined area has a corresponding set of predetermined reference stations that serve each predetermined area. Thus, if the approximate mobile device location 210 falls within a predetermined area, a corresponding set of predetermined reference stations may be selected. An example of how this can be implemented is described below with reference to Figure 5.

[0028] It should be noted that the density of reference stations may vary depending on the network capacity. In some embodiments of the RTK / DGNSS system 100, reference stations R1-R4 may be located only a few kilometers apart. In other embodiments, such as the RTK / DGNSS system 100 implementing ULB-RTK, reference stations may be located hundreds of kilometers or more apart. The location and density of reference stations may also vary based on the geographical area.

[0029] The approximate mobile device location 210 may be determined by one of several methods depending on the desired functionality. In some embodiments, the approximate mobile device location 210 may be determined based on a previously determined GNSS-based position fix (e.g., GNSS, RTK, or DGNSS). In some embodiments, the approximate mobile device location 210 may be determined by the mobile device or server using a network-based positioning technique, which may use RF signals to perform multi-lateration and / or multi-angulation of the mobile device to determine the mobile device location based on the known position of an RF transceiver (e.g., a Wi-Fi access point, a cellular network-based station, etc.).

[0030] Figure 3 is similar to Figure 2, showing the positions R1-R4 of the four reference stations and the approximate mobile device location 210. However, in this example, the reference station selection is not solely based on proximity to the approximate mobile device location 210. Instead, a “balanced” group of reference stations is selected such that the distance 320 between the centroid 330 of the polygon 340 formed by the approximate mobile device location 210 and the positions of the selected reference stations is minimized. If two reference stations are selected, the embodiment will minimize the distance between the midpoint of the line formed between the two reference stations and the approximate mobile device location 210. In some embodiments, the “balanced” group may be selected along with a fixed number N of reference stations, which may be selected or predetermined according to one or more of the embodiments described above.

[0031] It should be noted that this balanced approach does not necessarily result in selecting the nearest base station. As shown in Figure 3, when base station R5 is selected instead of base station R2, the resulting centroid 360 of the polygon formed by R1, R5, R3, and R4 is actually further away than the centroid 330 formed when R2 is used, even though R5 is closer to the approximate mobile device position 210 than R2. Selecting R2 instead of R5 shifts the centroid in the direction indicated by the dashed arrow.

[0032] This balanced approach can be beneficial in a variety of scenarios. For example, a mobile device may be surrounded by buildings or geographical features that obstruct some portion of the sky. A reference station may be similarly surrounded by such buildings or geographical features. Therefore, even a nearby reference station may not be able to provide sufficient correction data for satellites visible to the mobile device. However, by making a balanced selection of reference stations on various opposing sides of the approximate mobile device position 210, the embodiment can help increase the number of common-view satellites between the mobile device and the selected reference station.

[0033] For similar reasoning, this balanced selection of reference stations may be beneficial in RTK / DGNSS systems with a distributed network of reference stations, where the reference stations are hundreds or thousands of kilometers apart. In such systems, a mobile device may not have many common-view satellites with any given reference station. However, by receiving a balanced group of reference stations, the embodiment can help increase the number of common-view satellites between the mobile device and the selected reference stations. Generally, increasing the number of common-view satellites results in increased accuracy of each position determination. In a particular example, having a set of three or more satellites that are line of sight to both the mobile device and at least one of the multiple reference stations can help ensure error correction for at least the minimum number of satellites used for position determination. That being said, the embodiment can also be used when only a small number (or none at all) of common-view satellites are available. With respect to common-view satellites, another technique for reference station selection may be used, as shown in Figure 4.

[0034] Figure 4 is a sky plot 400 illustrating the various azimuths and altitudes of SV140 that can be seen (observed) by base stations R1 and R2. It should be noted that only portions of the SV are labeled to avoid clutter. As illustrated, SV140 can be characterized as line-of-sight by base station R1, line-of-sight by base station R2, or line-of-sight by base stations R1 and R2.

[0035] According to some embodiments, base station selection may be performed to maximize the common view satellite between the selected base station and the mobile device. Depending on the desired functionality, base station selection may be based on information received from the mobile device and / or base station regarding line-of-sight SV140s. Using the RTK / DGNSS system 100 in Figure 1 as an example, the mobile device 110 may send a request to the position fix service provider 170 for RTK / DGNSS correction data. The request may include, or may be accompanied by, information regarding line-of-sight SV140s to the mobile device 110 (for example, based on correction data acquired by the GNSS receiver of the mobile device 110). Service provider 170 may then select a reference station 120 based on the line-of-sight SV140 at each of the reference stations 120, and the reference stations 120 may be provided to service provider 170 periodically (e.g., every 30 seconds, every 1 minute, every 5 minutes, etc.) by the reference stations based on a triggering event (e.g., determination of a change in the line-of-sight SV140), at the request of service provider 170, etc. Additionally or alternatively, reference station selection may be based on the line-of-sight SV140 at the mobile device and / or reference station, such that it is calculated based on the approximate location of the mobile device, the known location of the reference station, and the calculated or known current position of the SV140.

[0036] In the example shown in Figure 4, if the sky plot 400 indicates an SV140 that is line of sight to the mobile device, base stations R1 and R2 may be selected based on the fact that at least one of the SV140s that is line of sight to the mobile device is also line of sight to base stations R1 and R2. In some embodiments, base stations R1 and R2 may be selected based on the fact that all of the SV140s that are line of sight to the mobile device are also line of sight to base stations R1, R2, or both.

[0037] In some embodiments, correction data from a base station may be provided to the mobile device based on its location within the area served by the mobile carrier network. An example of this is shown in Figure 5.

[0038] Figure 5 is a schematic diagram illustrating how data from various reference stations may be provided to various mobile devices 110 based on the location of each mobile device within the area served by the mobile carrier network. The example shown in Figure 5 illustrates how reference station selection may be based on the beam 505 transmitted by the cellular base station 520, but alternative embodiments may provide various reference station correction data based on other location-based criteria, such as serving cells, wireless heatmaps (e.g., locations based on detected transmitters and (optionally) transmission intensity).

[0039] The example shown in Figure 5 illustrates a cellular base station 520 in a fifth-generation New Radio (5G NR) carrier network capable of transmitting RF signals in different directions using different beams 505. Cellular base stations 520 in a 5G NR network are also called next-generation node B or gNB. Using beams, base station 520 can communicate data specific to devices in the area served by a particular beam 505. According to the embodiment, this can enable the mobile network to provide reference station correction data specific to the area served by one or more beams 505 of one or more base stations 520. In Figure 5, a first mobile device 110-1 is located in a first area 540-1 served by the first beam 505-1a of the first base station 520-1 and the first beam 505-2a of the second base station 520-2. Additionally, a second mobile device 110-2 located in the second area 540-2 is served by the second beam 505-1b of the first base station 520-1 and the second beam 505-2b of the second base station 520-2. According to some embodiments, base station 520 may provide different base station correction data on different beams via broadcast or specific transmission to one or more devices in area 540 served by beam 505. Thus, each of the beams 505-1a, 505-1b, 505-2a, and 505-2b used to transmit base station correction data may transmit base station correction data from a different set of one or more base stations. For example, beam 505-1a may be used to transmit correction data from base stations R1 and R2, beam 505-1b may be used to transmit correction data from base stations R1, R3, and R4, beam 505-2a may be used to transmit correction data from base station R5, and beam 505-2b may be used to transmit correction data from base stations R1, R2, R4, and R5.In this way, different areas 540 served by base station 520 may receive base station correction data from different combinations of base stations, where the combination of base stations for a given area 540 is known in order to enable accurate RTK / DGNSS position determination for mobile devices 110 within the area 540. Alternative configurations may serve the area 540 using a different number of base stations 520, including a single base station or three or more base stations.

[0040] The decision of which base station correction data to use for a particular beam 505 (or, more generally, a particular area 540 served by a mobile carrier network) may be made by a server at the base station, a location server in the network (e.g., a location management function (LMF) in a 5G NR network), and / or other computer servers communicably coupled to the base station 520. The server may receive feedback from mobile devices 110, inputs from external sources (e.g., network operators), data from base stations, and / or similar inputs, and may employ machine learning and / or other algorithms to determine the effectiveness of different base station correction data in different areas 540 served by the mobile carrier network.

[0041] Once a reference station 120 is selected or identified (for example, using one or more of the techniques described earlier), the way in which the corresponding reference correction data from these reference stations 120 is provided to the mobile device 110 may change. This may depend on any of a variety of factors, including available bandwidth, performance requirements, desired functionality, and / or other factors. Figure 6 and the following description provide several embodiments of how correction data from reference stations 120 may be provided to the device 110.

[0042] Figure 6 illustrates how various scheduling methods may be employed to provide base station correction data to a mobile device 110 based on bandwidth or performance requirements, according to several embodiments. As with other figures in this specification, it should be understood that the examples provided in Figure 6 are not limiting. Embodiments may use additional or alternative scheduling methods depending on the desired functionality. Here, the correction data is represented by different blocks, where blocks R1, R2, and R3 represent correction data from the first, second, and third base stations 120, respectively. Times are indicated as T0, T1, T2, etc., and may represent the time when a set of base station correction data is transmitted. More precisely, these times may represent the time when a server or cellular base station begins transmitting the base station correction data to the mobile device 110. Note that the set of base station correction data may be transmitted by a single server or cellular base station, or a subset or the entire set of base station correction data may be transmitted by two or more servers or cellular base stations. Subsets transmitted by different servers or cellular base stations may complement each other as described above with respect to Figure 5. Further, these subsets transmitted by different servers or cellular base stations may partially or completely overlap to provide redundancy in scenarios where availability is important. Additionally, cellular base stations may be located at least partially separately from base stations. In some embodiments, some or all cellular base stations may be located together with their respective base stations, or provided by their respective base stations.

[0043] The first scheduling method 600-1 utilizes the maximum bandwidth to provide base station correction data from all base stations (R1, R2, and R3) in every time interval (T0, T1, and T2). The second scheduling method 600-2 utilizes a slightly smaller bandwidth, providing base station correction data from two base stations (R1 and R2) per time interval and from a third base station (R3) in every other time interval. The third scheduling method 600-3 utilizes an even smaller bandwidth by switching between providing base station correction data from two base stations (R1 and R2) and from a third base station (R3) in every other interval. Finally, the fourth scheduling method 600-4 utilizes the minimum rate, providing base station correction data from a single base station in each time interval, and rotating from one base station to the next in each time interval. As those skilled in the art will understand, different scheduling methods may be used for different numbers of reference stations in order to accommodate different bandwidths or performance requirements, etc.

[0044] Generally, increased amounts of reference station correction data can result in higher performance. Therefore, as the amount of data provided to the mobile device 110 decreases from Method 600-1 to Method 600-4, the corresponding performance may also decrease. Method 600-4 may result in less accurate position determination than Method 600-1, for example. However, Method 600-4 uses a much smaller bandwidth than Method 600-1. Therefore, according to the desired functionality, the scheduling method may be selected based on the desired (or required) balance between performance and available bandwidth.

[0045] As described above, the base station correction data for a given base station 120 may include highly accurate GNSS measurements of one or more satellites acquired by the base station 120. The mobile device 110 can then use this information, along with position information about the base station 120, to perform DGNSS / RTK correction on the GNSS measurements acquired by the mobile device 110 in the manner described above, thereby obtaining highly accurate position determination for the mobile device 110. In some embodiments, the correction data may include position information for the base station 120, may be included in the correction data sent to the mobile device 110 (for example, in the block shown in Figure 6), or such correction data may be considered. Alternatively, position information may be provided separately. According to some embodiments, the mobile device 110 may maintain a database or almanac of base station position information that may be provided by the service provider 170. The way in which the mobile device 110 may use the base station correction data to improve position determination performance may vary depending on the desired functionality.

[0046] According to the first option, for example, the mobile device 110 may estimate the spatial distribution of DGNSS / RTK correction values ​​using the geometry of the base station. In this way, the mobile device 110 can interpolate DGNSS / RTK correction values ​​at a given position, similar to the techniques performed by the service provider 170 in conventional network-based DGNSS / RTK positioning. However, since the mobile device 110 can perform GNSS-based positioning to determine its position (with accuracy of several meters), it does not rely on interpolating DGNSS / RTK correction values ​​at a given position. Instead, the mobile device 110 can determine a more precise interpolation specific to its GNSS-based position. Thus, the resulting interpolated DGNSS / RTK correction value may be more precise and ultimately represent a corresponding high-precision position determination for the mobile device 110.

[0047] According to the second option, the mobile device 110 may run multiple instances of the positioning engine. As previously stated, the mobile device 110 may include a position estimator, which may be implemented by one or more hardware and / or software components of the mobile device 110 (as will be described in more detail below). According to the second option, the position estimator may include multiple instances of the positioning engine (e.g., PPEs using estimation techniques such as EKF, WLS, hatch filters, particle filters). For each of the multiple base stations 120, the corresponding positioning engine can resolve the baseline between the UE and each base station using base station correction data for each base station, resulting in multiple baseline solutions. The mobile device 110 can then calculate a position determination from the multiple baseline solutions.

[0048] Depending on the desired functionality, multiple baseline solutions may be combined in various ways. For example, according to some embodiments, baseline solutions may be combined simply by using an average, such as a simple average or a weighted average. According to some embodiments, baselines may be weighted according to their baseline length (for example, shorter baselines may be given a greater weight than longer baselines). As an addition or alternative, baselines may also be weighted based on satellite geometry (for example, baselines determined using multiple constellations with many satellites may be given a greater weight than baselines determined using a single constellation and / or fewer satellites). Alternative embodiments may employ additional or alternative techniques for combining baseline solutions.

[0049] According to the third option, the mobile device 110 may run a single positioning engine to process base station correction data from multiple base stations 120 to derive a single solution. That is, in contrast to the second option described above, the positioning engine of the mobile device 110 may be capable of processing multiple inputs to derive a single positioning solution. For example, a centralized Kalman filter may be used to process all baselines using base station correction data from multiple base stations 120 and to resolve ambiguities (e.g., with respect to RTK). More specifically, according to some embodiments, a centralized Kalman filter may be used to estimate the position of the mobile device (e.g., X, Y, and Z coordinates), receiver clock errors from each base station, inter-satellite-type bias (ISTB), base station tropospheric zenith delay, and / or other ambiguities. As those skilled in the art will understand, such a centralized Kalman filter may be more difficult to implement than simply combining the outputs of multiple Kalman filters as described above with respect to the second option. However, this option may be advantageous from a performance standpoint (e.g., accuracy, processing usage) depending on the upper limits.

[0050] It should be noted that embodiments utilizing one or more of the options described above for processing base station correction data may offer various performance advantages. Positioning for the mobile device 110 based on base station correction data from multiple base stations 120 may be more accurate and / or faster than positioning based on base station correction data from a single base station 120, due to several constraints included in the multiple reference method. Additionally or alternatively, the use of base station correction data from multiple base stations 120 may offer availability advantages. That is, if one base station 120 is down, the embodiment can continue to perform positioning for the mobile device 110 using base station correction data from one or more additional base stations 120.

[0051] This is similarly applicable to sparse base station networks. For example, in a sparse RTK / DGNSS system 100 with long distances between stations (e.g., 1000 km or more), there may be only a relatively small number of SV140s that are line-of-sight common to both the base station 120 and the mobile device 110. However, there may be many more SV140s that are line-of-sight common to the mobile device 110 and multiple base stations 120 (as previously explained with respect to Figure 4, for example). Therefore, when the mobile device 110 receives base station correction data from multiple base stations 120, the mobile device 110 may select RTK / DGNSS correction information for line-of-sight common SV140s from different base stations 120. Thus, the amount of RTK / DGNSS correction information available to the mobile device 110 receiving base station correction data from multiple base stations 120 may be greater than the amount of RTK / DGNSS correction information available from any single base station 120.

[0052] Figure 7 is a simplified overhead view of a mobile device and multiple base stations, illustrating how, in one embodiment, multiple constraints on values ​​derived from base station correction data from multiple base stations can be used to perform position determination for a mobile device. The various values ​​in Figure 7 are as follows: POS U This represents the (strict) position of the mobile device, POS R1 represents the (strict) position of the first reference station, POS R2 This represents the (strict) position of the second reference station, POS R3 This represents the (strict) position of the third reference station.

[0053]

number

[0054] This is the position vector from the first reference station to the mobile device,

[0055]

number

[0056] This is the position vector from the second reference station to the mobile device.

[0057]

number

[0058] This is the position vector from the third reference station to the mobile device. As with other figures provided herein, Figure 7 is provided as a non-limiting illustrative example. Characteristics such as the number of reference stations and their relative positions to each other and to the mobile device may vary from situation to situation.

[0059] As stated, the values ​​shown in Figure 7 may be derived from the known position of the base station, along with base station correction data from the base station. Constraints on these values ​​can be used to check the reliability and completeness of the base station correction data. Furthermore, these constraints can be used to more quickly determine the mobile device position (POS). U This may enable the determination of ). Some constraints may be expressed by the following equation.

[0060]

number

[0061] Equation (1) is a position vector consistency check that uses the known position of the base station and the vector from the base station to the mobile device. The base station position plus the vector to the mobile device should equal the mobile device position. This should be the same for all base stations. Base station correction data for a base station may be ignored if it does not match the base station correction data for other base stations. More details,

[0062]

number

[0063] ,

[0064]

number

[0065] , and

[0066]

number

[0067] This may represent each of the baseline solutions described above. Based on position vector consistency checks, one or more baseline solutions may be removed from further processing based on their deviation from the determined mobile device position, for example, by exceeding a threshold or exceeding another baseline solution. Additional or alternative voting logic or deweighting, as described below, may be applied.

[0068] Equation (2) is a position vector constraint resulting from the relative relationship between the positions of the mobile device, the first base station, and the second base station. As shown in Figure 8, the position vector between the first base station and the second base station (which can be derived from the known positions of the first and second base stations)

[0069]

number

[0070] This is the position vector from the first reference station to the mobile device.

[0071]

number

[0072] position vector from the mobile device to the second base station

[0073] [Math.]

[0074] is equal to the sum of the foregoing. As will be appreciated, similar constraints may be derived from the relationship between (i) the mobile device, the second base station, and the third base station and (ii) the mobile device, the third base station, and the first base station. Again, data from one base station may be ignored if it does not match data from other base stations. Removal of data from one or both base stations for further processing may again be determined based on how much each baseline solution deviates from the determined mobile device position (POS U ) and / or how much the left-hand side and right-hand side of equation (2) differ, for example by comparing the norm of the difference with a maximum allowable deviation. Additionally or alternatively, downweighting as described below may be used.

[0075] Equation (3) is a carrier phase ambiguity check that may be used in RTK implementations. Similar to equation (2) in the method, the carrier phase ambiguity (Δ∇Amb 12 ) for the baseline between the first base station and the second base station is equal to the carrier phase ambiguity (Δ∇Amb 1U ) between the first base station and the mobile device plus the carrier phase ambiguity (Δ∇Amb U2This is equivalent to adding (i) to (ii) the baseline between (i) the mobile device, the second base station, and the third base station, and (ii) the baseline between the mobile device, the third base station, and the first base station. Again, data from one base station may be ignored if it does not match the data from the other base station. Corresponding criteria for removing data from one or both base stations from further processing may be applied based on carrier phase ambiguity. Additional or alternative unweighting, as described below, may be applied.

[0076] Formulas (1), (2), and / or (3) may be used as data integrity checks to determine whether the base station correction data is good. As stated, base station correction data from a base station may be ignored if it fails any or all of these checks. Voting logic using three or more base stations may be used, for example, to identify and ignore information from non-compliant base stations.

[0077] As an addition or alternative, such as when only base station data from two base stations are available, equations (1), (2), and / or (3) may be used to determine whether a position determination based on base station correction data is good. For example, if an error is detected using equations (1), (2), and / or (3), the position determination may be determined to be unreliable and may then be ignored or unweighted accordingly.

[0078] Figure 9A is a flowchart of Method 900-A, according to one embodiment, for providing base station correction data to a mobile device for RTK or DGNSS correction. Method 900-A can utilize the techniques described above and can therefore be seen as one implementation of the previously described processes, including the processes shown in Figures 2 to 5. Alternative embodiments may have different functionalities by combining, separating, or otherwise modifying the functionalities described in the blocks shown in Figure 9A. Means for performing one or more functionalities from the blocks shown in Figure 9A may comprise hardware and / or software components of a computer system, such as the components shown in Figure 12 and described below herein. The computer system may comprise a computer server corresponding to the service provider 170 shown in Figure 1 and described above in this embodiment.

[0079] In block 910, functionality includes receiving information indicating the approximate location of the mobile device, or information regarding satellite vehicles within line of sight of the mobile device. As described in the embodiments described above, the approximate location of the mobile device may be determined by any of a variety of methods, such as previously determined GNSS-based position fix (e.g., GNSS, RTK, or DGNSS), sensor-based positioning (e.g., dead reckoning, image-based positioning, etc.), and / or network-based positioning techniques (which may use RF signals to determine the mobile device location based on the known position of the RF transceiver by performing multi-lateration and / or multi-angulation of the mobile device). Network-based positioning techniques may include, for example, multi-round-trip time (RTT), observed time-to-arrival difference (OTDOA) or downlink time-to-arrival difference (DL-TDOA), angle of arrival (AOA), angle of departure (AOD), and / or other positioning procedures that may be performed, for example, within a cellular or wireless local area network (WLAN). Information regarding satellite vehicles within line of sight may be obtained by the mobile device itself. Information regarding the approximate location of a mobile device, or of satellite vehicles visible to the mobile device, may be provided by the mobile device itself (for example, via a data communication network 150, such as a cellular network and / or the internet) or by another entity. In some embodiments, for example, a mobile network may be able to provide the approximate location of the mobile device.

[0080] Means for performing the functionality in block 910 may include one or more software and / or hardware components of the computer system 1200, such as the bus 1205, processing unit 1210, communication subsystem 1230, working memory 1235, and / or other software and / or hardware components, as shown in Figure 12 and described in more detail below.

[0081] In block 920, the functionality comprises selecting multiple reference stations from which reference station correction data should be obtained, and the selection is at least partially based on the approximate location of the mobile device. Different techniques may be used to select the reference stations, as previously described with reference to Figures 2-5. For example, the reference stations may be selected to maximize the number of common-view GNSS satellites between the mobile device and the multiple reference stations. This "balanced" approach may be particularly useful when the distances between the reference stations are large (e.g., several hundred kilometers or more) and different reference stations may have different common-view satellites with the mobile device. According to some embodiments, in order to maximize the number of common-view GNSS satellites between the mobile device and the multiple reference stations, the method may further comprise obtaining information from each of the multiple reference stations about the GNSS satellites that can be seen by each of the reference stations, or obtaining information from the mobile device about the GNSS satellites that can be seen by the mobile device, or both.

[0082] According to some embodiments, the selection of multiple reference stations may, additionally or alternatively, be based on the respective locations of each of the multiple reference stations. In such embodiments, the selection of multiple reference stations may be based on the proximity of each of the multiple reference station locations to the approximate location of the mobile device. For example, the radius-based selection shown in Figure 2 is a form of this type of reference station selection. In some embodiments, reference stations may be selected to minimize the distance between the midpoint or centroid of the reference station locations and the approximate location of the mobile device. For example, the process shown in Figure 3 is a form of this type of reference station selection.

[0083] Means for performing the functionality in block 920 may include one or more software and / or hardware components of the computer system 1200, such as the bus 1205, processing unit 1210, working memory 1235, and / or other software and / or hardware components, as shown in Figure 12 and described in more detail below.

[0084] In block 930, the functionality comprises obtaining base station correction data from each of a plurality of base stations, for each base station the base station correction data comprises data based on one or more measurements of RF signals from one or more GNSS satellites acquired by a GNSS receiver at each base station. As those skilled in the art will understand, this base station correction data may be used by a mobile device to perform RTK or DGNSS correction on GNSS satellite measurements acquired by the mobile device. As stated above, the correction data may include correction information based on the measurement data and the known position of each base station. Additionally or alternatively, the correction data may include the measurement data itself and (optionally) position information for each base station. To enable a mobile device to determine its position, the base station correction data for a given base station may include, or be associated with, timing information about when one or more measurements of RF signals from one or more GNSS satellites were acquired by the base station, position information about the position of the base station, etc.

[0085] Means for performing the functionality in block 930 may include one or more software and / or hardware components of the computer system 1200, such as the bus 1205, processing unit 1210, communication subsystem 1230, working memory 1235, and / or other software and / or hardware components, as shown in Figure 12 and described in more detail below.

[0086] In block 940, the functionality comprises sending base station correction data to a mobile device. As previously stated, a computer server (e.g., a service provider 170) may be communicably coupled to the mobile device 110 via a data communication network 150. The data communication network 150 may comprise any of various public and / or private networks, including the Internet, a mobile communication network, etc. Thus, in some embodiments, sending base station correction data to a mobile device may comprise transmitting base station correction data from one or more mobile network base stations. As previously described with reference to Figure 5, different selections of base stations may be made for different mobile devices in different locations within different coverage areas (e.g., area 540) of one or more mobile network base stations. Thus, according to some embodiments, where the approximate location of a mobile device is within a first coverage area of ​​one or more mobile network base stations, method 900-A may further comprise sending correction data from a plurality of different base stations to a second mobile device in a second coverage area of ​​one or more mobile network base stations.

[0087] Means for performing the functionality in block 940 may include one or more software and / or hardware components of the computer system 1200, such as the bus 1205, processing unit 1210, communication subsystem 1230, working memory 1235, and / or other software and / or hardware components, as shown in Figure 12 and described in more detail below.

[0088] Figure 9B is a flowchart of method 900-B, according to another embodiment, for providing base station correction data to a mobile device for RTK or DGNSS correction. The functionality in the blocks in Figure 9B is similar to the corresponding blocks in Figure 9A. The only difference is that in Figure 9B, the functionality in block 925 explicitly refers to the selected base stations as a "subset of available base stations from which base station correction data should be obtained," and this subset is later referenced in block 935. Similar to method 900-A in Figure 9A, the techniques described above can be utilized. In detail, the selection of the subset may involve one or more of the previously described processes shown in Figures 2 to 5. Alternative embodiments may vary the functionality by combining, separating, or otherwise modifying the functionality described in the blocks shown in Figure 9B. Means for performing one or more of the functionality in the blocks shown in Figure 9B may comprise hardware and / or software components of a computer system, such as the components shown in Figure 12 and described below herein. The computer system may comprise a computer server corresponding to the service provider 170 shown in Figure 1 and described above in this embodiment.

[0089] Figure 10A is a flowchart of Method 1000-A for applying RTK or DGNSS correction in a mobile device according to one embodiment. Method 1000-A can utilize the techniques described above and can therefore be seen as one implementation of the previously described process, including the process described with reference to Figures 2 to 7. Alternative embodiments may have different functionalities by combining, separating, or otherwise modifying the functionalities described in the blocks shown in Figure 10A. Means for performing one or more functionalities from the blocks shown in Figure 10A may include hardware and / or software components of a mobile device, such as the components shown in Figure 11 and described below herein.

[0090] In block 1005, the functionality optionally includes sending a request to a server and / or one or more mobile network base stations for reference station correction data. As previously stated, the mobile device can request DGNSS / RTK correction data and send a request to a DGNSS / RTK service provider. The request may include the approximate location of the mobile device (for example, based on a previously known position, non-GNSS-based positioning, etc.) and may also include an indication of the mobile device's ability to interpolate the correction data. According to some embodiments, the request may additionally or alternatively include a QoS indicator and / or a requested number N of reference stations. Means for performing the functionality in block 1005 may include one or more software and / or hardware components of the computer system 1100, such as the bus 1105, processing unit 1110, wireless communication interface 1130, memory 1160, and / or other software and / or hardware components of the mobile device 110, as shown in Figure 11 and described in more detail below.

[0091] In block 1010, the functionality comprises acquiring base station correction data on a mobile device from each of a plurality of base stations, wherein for each base station, the base station correction data comprises data based on one or more measurements of RF signals from one or more GNSS satellites acquired by a GNSS receiver at each base station. The base station correction data from each of the plurality of base stations is limited to correction data associated with or acquired at each respective base station. According to embodiments of the present disclosure, the base station correction data does not include base station correction data for any other base station among the plurality of base stations. As stated, the correction data may include correction information based on measurement data and the known location of each base station. Additionally or alternatively, the correction data may include the measurement data itself and (optionally) location information for each base station. As previously described, the base station correction data may be acquired from a computer server and / or one or more mobile network base stations. According to some embodiments, acquiring base station correction data from a computer server may comprise initiating a communication session between the mobile device and the computer server.

[0092] Means for performing the functionality in block 1010 may include one or more software and / or hardware components of the computer system 1100, such as the bus 1105, processing unit 1110, wireless communication interface 1130, memory 1160, and / or other software and / or hardware components of the mobile device 110, as shown in Figure 11 and described in more detail below.

[0093] In block 1020, the functionality comprises acquiring mobile device measurement data, which comprises one or more measurements of RF signals from one or more GNSS satellites obtained by a GNSS receiver in the mobile device. As those skilled in the art will understand, the mobile device can perform high-accuracy position determination by using the reference station correction data acquired in block 1010 to perform RTK or DGNSS correction on the mobile device measurement data.

[0094] Means for performing the functionality in block 1020 may include one or more software and / or hardware components of the computer system 1100, such as the bus 1105, processing unit 1110, GNSS receiver 1180, memory 1160, and / or other software and / or hardware components of the mobile device 110, as shown in Figure 11 and described in more detail below.

[0095] In block 1030, the functionality comprises determining the position of a mobile device based on base station correction data from each of several base stations and mobile device measurement data. As previously described, the mobile device can use base station correction data without the need for interpolated RTK / DGNSS correction information as used in conventional RTK / DGNSS systems. Position determination can instead be performed, for example, by combining position determinations made from base station correction data from different base stations, or by using a single Kalman filter to process base station correction data from multiple base stations. Thus, according to some embodiments of Method 1000-A, determining the position of a mobile device in block 1030 may comprise determining an estimated position of the mobile device for each of several base stations based on base station correction data from each base station and mobile device measurement data, and combining all the estimated positions to determine the position of the mobile device. Furthermore, according to some embodiments, combining all estimated positions may comprise taking a simple average or a weighted average of the estimated positions. Alternatively, according to some embodiments, determining the location of a mobile device involves using a single Kalman filter to process base station correction data from all base stations of multiple base stations.

[0096] Means for performing the functionality in block 1030 may include one or more software and / or hardware components of the computer system 1100, such as the bus 1105, processing unit 1110, memory 1160, and / or other software and / or hardware components of the mobile device 110, as shown in Figure 11 and described in more detail below.

[0097] As previously described with respect to equations (1) to (3), checks may be performed on the estimated mobile device position and / or other values ​​determined from the reference station correction data to determine whether the reference station correction data and / or estimated mobile device position are accurate. Thus, some embodiments of Method 1000-A may further provide verification of the accuracy of the determined position of the mobile device using carrier phase integer ambiguity or position vectors from at least two of a plurality of reference stations.

[0098] Some embodiments may include additional or alternative features as described herein. For example, some embodiments of Method 1000-A may include ignoring base station correction data from one or more base stations out of a plurality of base stations based on verification of the accuracy of the determined location of the mobile device, and determining the improved location of the mobile device based on the remaining base station correction data from the plurality of base stations and mobile device measurement data.

[0099] As an addition or alternative, as stated above, Method 1000-A may comprise sending a request to the provider service for reference station correction data. According to some embodiments, the request includes information indicating the approximate location of a mobile device. As an addition or alternative, the request includes at least one of the following: quality of service (QoS) or the number of reference stations to be included among multiple reference stations.

[0100] According to some embodiments, method 1000-A may further comprise obtaining base station correction data from each of a plurality of base stations, or receiving base station correction data from one or more mobile network base stations. Receiving base station correction data from one or more mobile network base stations may further comprise repeatedly receiving base station correction data from one or more mobile network base stations. According to some embodiments, the repetition rate of receiving base station correction data may be based on at least one of the bandwidth of wireless communication with one or more mobile network base stations, or performance requirements for determining the location of a mobile device.

[0101] Figure 10B is a flowchart of Method 1000-B, which applies RTK or DGNSS correction in a mobile device according to another embodiment. Similar to Method 1000-A in Figure 10A, Method 1000-B can utilize the techniques described above and can therefore be seen as an implementation of the previously described process, including the process described with reference to Figures 6-7. Furthermore, the functionality in the blocks in Figure 10B is similar to the corresponding blocks in Figure 10A. The main difference in Figure 10B is the functionality in block 1007, which includes the explicit selection of a subset of available reference stations from which reference station correction data should be obtained, and such selection can be performed by the mobile device itself. That is, according to some embodiments, the reference station location and (optionally) other information for reference station selection (e.g., using the selection techniques shown in Figures 2-5 and described above) can be provided to the mobile device, enabling the mobile device to perform the reference station selection. Information for base station selection may be obtained by a mobile device, for example, via a broadcast and / or data communication network 150 (e.g., the Internet and / or another data network). The functionality of blocks 1015 and 1035 in Figure 10B mimics the functionality of blocks 1010 and 1030, respectively, in Figure 10A, except that blocks 1015 and 1035 explicitly refer to the selected base station as “a subset of available base stations from which base station correction data should be obtained,” similar to Figure 9B. Alternative embodiments may have altered functionality by combining, separating, or otherwise modifying the functionality described in the blocks shown in Figure 10B. Means for performing one or more of the functionality of the blocks shown in Figure 10B may include hardware and / or software components of a mobile device, such as the components shown in Figure 11 and described below herein.

[0102] Figure 10C is a flowchart of Method 1000-C, which applies RTK or DGNSS correction in a mobile device according to another embodiment. Method 1000-C comprises further variations of Methods 1000-A and 1000-B in Figures 10A and 10B. Here, the functionality in block 1010 may be the same as the corresponding block 1010 in Figure 10A, and comprises acquiring base station correction data in the mobile device from each of a plurality of base stations, for each base station, the base station correction data comprises data based on one or more measurements of RF signals from one or more GNSS satellites acquired by a GNSS receiver at each base station. The functionality in block 1017 comprises selecting a subset of a plurality of base stations from which the acquired base station correction data should be used, the subset comprising a plurality of base stations, and the selection is at least in part based on the approximate location of the mobile device or information about satellite vehicles visible to the mobile device. That is, in contrast to the functionality in block 1007 of Method 1000-B, from which a reference station is selected from which reference station correction data should be obtained, the functionality in block 1017 involves a post-selection of the reference station from which the correction data was obtained. For example, this may be the case in an implementation in which a mobile device obtains correction data via broadcast. Again, this selection may use one or more of the selection techniques shown in Figures 2 to 5 and described above. Method 1000-C can then proceed similarly to Method 1000-B, where measurement data is obtained (in block 1020) and the location of the mobile device is determined (in block 1035) based on the measurement data and reference station correction data from each of the subset reference stations. Alternative embodiments may vary the functionality by combining, separating, or otherwise modifying the functionality described in the blocks shown in Figure 10C. Means for performing one or more of the functionality in the blocks shown in Figure 10C may include hardware and / or software components of the mobile device, such as the components shown in Figure 11 and described below herein.

[0103] Figure 11 is a block diagram of various hardware and software components of a mobile device 110 according to one embodiment. These components can be used as described above in this specification (for example, in relation to Figures 1 to 10). For example, the mobile device 110 can perform the operation in the manner shown in Figures 10A to 10C, and / or one or more of the functions of the mobile device 110 as described in the embodiments herein. Note that Figure 11 is intended only to provide a generalized example of various components, and any or all of the components may be used as appropriate. As previously stated, the mobile device 110 may vary in form and function and may ultimately comprise any GNSS-enabled device, including vehicles, commercial and consumer electronic devices, surveying equipment, etc. Thus, in some cases, the components shown in Figure 11 can be localized to a single physical device and / or distributed among various networked devices that may be located at different physical locations (e.g., different locations on a vehicle). It should be further noted that the reference station may utilize hardware and / or software components similar to the mobile device 110 and / or computer system 1200 (described below) to provide the functionality described herein.

[0104] A mobile device 110 is illustrated, comprising hardware elements that can be electrically coupled via bus 1105 (or, as appropriate, communicate in other ways). The hardware elements may include a processing unit 1110, which may include, but not limited to, one or more general-purpose processors, one or more dedicated processors (such as digital signal processing (DSP) chips, graphics processing units (GPUs), application-specific integrated circuits (ASICs), and / or other processors, processing structures, or processing means. As shown in Figure 11, some embodiments may have a separate digital signal processor (DSP) 1120 depending on the desired functionality. Location determination and / or other determinations based on wireless communication may be performed in the processing unit 1110 and / or the wireless communication interface 1130 (described below). The mobile device 110 may also include one or more input devices 1170, which may include, but are not limited to, a keyboard, touchscreen, touchpad, microphone, buttons, dials, switches, etc., and one or more output devices 1115, which may include, but are not limited to, a display, light-emitting diodes (LEDs), speakers, etc. As understood, the types of input devices 1170 and output devices 1115 may depend on the type of mobile device 110 with which the input devices 1170 and output devices 1115 are integrated.

[0105] The mobile device 110 may also include a wireless communication interface 1130, which may comprise, but is not limited to, a modem, a network card, an infrared communication device, a wireless communication device, and / or a chipset (such as a Bluetooth® device, an IEEE 802.11 device, an IEEE 802.15.4 device, a Wi-Fi device, a WiMAX® device, a wide area network (WAN) device, and / or various cellular devices), thereby enabling the mobile device 110 to communicate with other devices via a network and / or directly, as described herein. The wireless communication interface 1130 may enable data and signaling to communicate with the network (e.g., transmit and receive) via, for example, a WAN access point, a cellular base station and / or other access node types, and / or other network components, computer systems, and / or any other electronic devices described herein. Communication may be performed via one or more wireless communication antennas 1132 that transmit and / or receive wireless signals 1134. Antenna 1132 may comprise one or more individual antennas, one or more antenna arrays, or any combination thereof.

[0106] Depending on the desired functionality, the wireless communication interface 1130 may include separate transceivers, separate receivers and transmitters, or any combination of transceivers, transmitters, and / or receivers for communicating with base stations and other ground transceivers such as wireless devices and access points. The mobile device 110 may communicate with different data networks, which may include various network types. For example, a wireless wide area network (WWAN) may be a code division multiple access (CDMA) network, a time division multiple access (TDMA) network, a frequency division multiple access (FDMA) network, an orthogonal frequency division multiple access (OFDMA) network, a single-carrier frequency division multiple access (SC-FDMA) network, a WiMAX® (IEEE 802.16) network, etc. A CDMA network may implement one or more radio access technologies (RATs), such as CDMA2000® or Wideband CDMA (WCDMA®). CDMA2000® includes the IS-95 standard, the IS-2000 standard, and / or the IS-856 standard. TDMA networks may implement the Global System for Mobile Communications (GSM), Digital Advanced Mobile Phone Systems (D-AMPS), or several other RATs. OFDMA networks may employ Long-Term Evolution (LTE), LTE Advanced, 5G NR, 6G, etc. 5G NR, LTE, LTE Advanced, GSM, and WCDMA® are documented in documents from the Third Generation Partnership Project (3GPP®). CDMA2000® is documented in documents from an organization named "Third Generation Partnership Project II" (3GPP® II). 3GPP® and 3GPP® II documents are publicly available. A wireless local area network (WLAN) may also be an IEEE 802.11x network, and a wireless personal area network (WPAN) may be a Bluetooth® network, an IEEE 802.15x network, or some other type of network.The techniques described herein may also be used for any combination of WWAN, WLAN, and / or WPAN.

[0107] The mobile device 110 may further include a sensor 1140. The sensor 1140 may comprise, but is not limited to, one or more inertial sensors and / or other sensors (e.g., accelerometers, gyroscopes, cameras, magnetometers, altimeters, microphones, proximity sensors, light sensors, barometers, etc.), some of which may be used in some cases to complement and / or facilitate the positioning described herein.

[0108] Embodiments of the mobile device 110 may also include a GNSS receiver 1180 capable of receiving signals 1184 from one or more GNSS satellites (e.g., SV140) as described herein, using an antenna 1182 (which may be the same as antenna 1132). The GNSS receiver 1180 can use conventional techniques to extract the position of the mobile device 110 from a GNSS SV (e.g., SV140 in Figure 3) of a GNSS system such as GPS, GAL, Global Navigation Satellite System (GLONASS), Quasi-Zenith Satellite System (QZSS) over Japan, Indian Regional Navigation Satellite System (IRNSS) over India, or Beidou Navigation Satellite System (BDS) over China. Furthermore, the GNSS receiver 1180 can be used with a variety of augmentation systems (e.g., satellite-based augmentation systems (SBAS)) that may be associated with, or otherwise enabled for use with, one or more global and / or regional navigation satellite systems, such as the Wide Area Augmentation System (WAAS), the European Geostationary Navigation Overlay Service (EGNOS), the Multifunction Satellite Augmentation System (MSAS), and the Geoaugmented Navigation System (GAGAN).

[0109] While the GNSS receiver 1180 shown in Figure 11 is presented as a separate component from the other components within the mobile device 110, it should be noted that embodiments are not so limited. The term “GNSS receiver” as used herein may comprise hardware and / or software components configured to acquire GNSS measurements (measurements from GNSS satellites). Thus, in some embodiments, the GNSS receiver may comprise a measurement engine executed (as software) by one or more processing units, such as the processing unit 1110, the DSP 1120, and / or the processing unit within the wireless communication interface 1130 (e.g., in a modem). The GNSS receiver may also optionally include a positioning engine, such as those described herein (e.g., EKF / Kalman filters, WLS, hatch filters, particle filters, etc.), which can determine the position of the GNSS receiver using GNSS measurements from the measurement engine and RTK / D GNSS correction information. The positioning engine may also be executed by one or more processing units, such as the processing unit 1110 and / or the DSP 1120.

[0110] The mobile device 110 may further include and / or communicate with memory 1160. Memory 1160 may comprise machine-readable or computer-readable media, which may include, but are not limited to, local storage and / or network-accessible storage, disk drives, drive arrays, optical storage devices, programmable, flash-updatable random-access memory (RAM) and / or read-only memory (ROM), and other solid-state storage devices. Such storage devices may be configured to implement any suitable data storage device, including, but are not limited to, various file systems, database structures, and the like.

[0111] The memory 1160 of the mobile device 110 may also comprise software elements (not shown in Figure 11) including other code such as an operating system, device drivers, executable libraries, and / or one or more application programs, which may comprise computer programs provided by various embodiments as described herein, and / or may be designed to implement methods provided by other embodiments and / or to constitute a system provided by other embodiments. As just one example, one or more procedures described with respect to the methods described above may be implemented as code and / or instructions in the memory 1160 that can be executed by the mobile device 110 (and / or a processing unit 1110 or DSP 1120 within the mobile device 110). In one embodiment, such code and / or instructions may then be used to configure and / or adapt a general-purpose computer (or other device) to perform one or more operations according to the methods described.

[0112] Figure 12 is a block diagram of one embodiment of a computer system 1200, which may be used and / or incorporated into a service provider 170, a reference station 120, a base station, a computer server, and / or other devices described herein. Figure 12 provides a block diagram of one embodiment of a computer system 1200 that can perform methods provided by various other embodiments, such as the methods described with respect to Figures 1 to 9. It should be noted that Figure 12 is intended only to provide generalized examples of various components, and any or all of the components may be used as appropriate. Thus, Figure 12 broadly illustrates how individual system elements may be implemented in a relatively isolated or relatively more integrated manner. In addition, as with the components of Figure 11, the components shown by Figure 12 can be localized in a single device and / or distributed among various networked devices that may be located in different physical or geographical locations.

[0113] A computer system 1200 is illustrated, comprising hardware elements that may be electrically coupled via bus 1205 (or, as appropriate, communicate in other ways). The hardware elements may include a processing unit 1210, which may include, but not limited to, one or more general-purpose processors, one or more dedicated processors (such as DSPs, ASICs, GPUs), and / or other processing structures that may be configured to perform one or more of the methods described herein, including the methods described with respect to Figures 9A and 9B. The computer system 1200 may also include, but not limited to, one or more input devices 1215, which may include a mouse, keyboard, camera, microphone, etc., and one or more output devices 1220, which may include a display device, printer, etc. The types of input devices 1215 and output devices 1220 may depend on the type of computer system 1200 in which the input devices 1215 and output devices 1220 are integrated.

[0114] The computer system 1200 may further include (and / or communicate with) one or more non-temporary storage devices 1225, one or more non-temporary storage devices 1225 may, but not limited to, provide local storage and / or network-accessible storage, and / or may include solid-state storage devices such as disk drives, drive arrays, optical storage devices, programmable, flash-updatable, etc., RAM and / or ROM. Such storage devices may be configured to implement any suitable data storage device, but not limited to, various file systems, database structures, etc.

[0115] The computer system 1200 may also include a communications subsystem 1230, which may include support for wireline and / or wireless communications technologies, managed and controlled by a wireless communications interface 1233 (in some embodiments). The communications subsystem 1230 may include a modem, a (wireless or wired) network card, an infrared communications device, a wireless communications device, and / or a chipset, etc. The communications subsystem 1230 may include one or more input and / or output communications interfaces, such as the wireless communications interface 1233, to enable data and signaling to be exchanged with networks, mobile devices, other computer systems, and / or any other electronic devices described herein. In particular, if the computer system 1200 includes a base station, the wireless communications interface 1233 may enable the base station to communicate wirelessly with one or more mobile devices 110.

[0116] In many embodiments, the computer system 1200 further comprises a working memory 1235 which may include RAM devices and / or ROM devices. Software elements shown as located within the working memory 1235 may include other code such as an operating system 1240, device drivers, executable libraries, and / or applications 1245, and such software elements may comprise computer programs provided by various embodiments as described herein, and may be designed to perform methods and / or configure the system as provided by other embodiments. As just one example, one or more procedures described with respect to the methods described above, such as the methods described with respect to Figures 9A and 9B, may be implemented as code and / or instructions that are stored (e.g., temporarily) in the working memory 1235 and are executable by the computer (and / or processing units within the computer, such as processing unit 1210), and in one embodiment, such code and / or instructions may then be used to configure and / or adapt a general-purpose computer (or other device) to perform one or more operations according to the methods described.

[0117] These instructions and / or sets of code may be stored on a non-temporary computer-readable storage medium, such as the storage device 1225 described above. In some cases, the storage medium may be incorporated into a computer system, such as computer system 1200. In other embodiments, the storage medium may be separate from the computer system (e.g., a removable medium such as an optical disc) and / or provided in an installation package, so that the storage medium may be used to program, configure, and / or adapt a general-purpose computer with the instructions / code stored thereon. These instructions may take the form of executable code that can be executed by computer system 1200, and / or in the form of source and / or installable code, which then takes the form of executable code when compiled and / or installed on computer system 1200 (e.g., using one of various commonly available compilers, installers, compression / decompression utilities, etc.).

[0118] It will be apparent to those skilled in the art that substantial modifications may be made to suit specific requirements. For example, customized hardware may be used, and / or certain elements may be implemented in hardware, software (including portable software such as applets), or both. Furthermore, connections to other computing devices, such as network input / output devices, may be employed.

[0119] Referring to the attached diagram, components that may include memory may also include non-temporary machine-readable media. As used herein, the terms “machine-readable media” and “computer-readable media” refer to any storage medium involved in providing data that enables a machine to operate in a particular manner. In the embodiments provided above, various machine-readable media may be involved in providing instructions / codes for execution to processing units and / or other devices. Additionally or alternatively, machine-readable media may be used to store and / or carry such instructions / codes. In many implementations, computer-readable media are physical and / or tangible storage media. Such media can take many forms, including, but are not limited to, non-volatile and volatile media. Common forms of computer-readable media include, for example, magnetic and / or optical media, any other physical media having a pattern of holes, RAM, programmable ROM (PROM), erasable PROM (EPROM), FLASH-EPROM, any other memory chip or cartridge, carriers as described below, or any other media from which instructions and / or code can be read by a computer.

[0120] The methods, systems, and devices described herein are examples. Various embodiments may omit, substitute, or add various procedures or components as appropriate. For example, features described in relation to some embodiments may be combined in various other embodiments. Different aspects and elements of these embodiments may be combined in similar ways. Various components of the figures provided herein may be embodied in hardware and / or software. Furthermore, technology evolves, and therefore many of the elements are examples that do not limit the scope of this disclosure to their specific examples.

[0121] For reasons of common usage, it is sometimes convenient to refer to such signals as bits, information, values, elements, symbols, characters, variables, terms, numbers, numerical values, etc. However, it should be understood that all of these or similar terms are merely labels for convenience and relate to appropriate physical quantities. Unless otherwise specified, as is evident from the above description, it is understood that throughout this specification, descriptions using terms such as “process,” “calculate,” “compute,” “determine,” “verify,” “identify,” “associate,” “measure,” and “execute” refer to actions or processes of specific devices such as dedicated computers or similar dedicated electronic computing devices. Therefore, in the context of this specification, dedicated computers or similar dedicated electronic computing devices or systems are capable of manipulating or converting signals that are generally expressed as physical electronic, electric, or magnetic quantities in the memory, registers, or other information storage devices, transmitting devices, or display devices of dedicated computers or similar dedicated electronic computing devices or systems.

[0122] As used herein, the terms “and” and “or” may have a variety of meanings, which are also expected to depend at least in part on the context in which such terms are used. Generally, when “or” is used to relate an enumeration such as A, B, or C, it is intended to mean A, B, and C as used here in an inclusive sense, as well as A, B, or C as used here in an exclusive sense. In addition, as used herein, the term “one or more” may be used to describe any single feature, structure, or characteristic, or to describe several combinations of features, structures, or characteristics. However, it should be noted that this is merely an illustrative example, and the claimed subject matter is not limited to this example. Furthermore, when the term “at least one of” is used to relate an enumeration such as A, B, or C, it may be interpreted to mean any combination of A, B, and / or C, such as A, AB, AA, AAB, AABBCCC, etc.

[0123] While several embodiments are described, various modifications, alternative configurations, and equivalents may be used without departing from the scope of the disclosure as defined by the appended claims. For example, the elements described above may be merely components of a larger system, other rules may take precedence over the applications of the various embodiments, or the applications of the various embodiments may be modified in a different way. Also, several steps may be commenced before, during, or after the consideration of the elements described above. Therefore, the above description does not limit the scope of the disclosure.

[0124] In light of this description, embodiments may include various combinations of features. Examples of implementations are described in the following numbered clauses. Clause 1: A method for providing reference station correction data to a mobile device for real-time kinematic (RTK) or differential global navigation satellite system (DGNSS) correction, the method comprising: receiving information indicating the approximate location of the mobile device or information regarding satellite vehicles visible to the mobile device; selecting a plurality of reference stations from which reference station correction data should be obtained, the selection being at least partially based on the approximate location of the mobile device or information regarding satellite vehicles visible to the mobile device; obtaining reference station correction data from each of the plurality of reference stations, the reference station correction data for each reference station comprising data based on one or more measurements obtained by a GNSS receiver at each reference station; and sending the reference station correction data to the mobile device. Clause 2: The method of Clause 1, the step of selecting multiple base stations, is additionally based on the respective locations of each of the multiple base stations. Clause 3: The method of Clause 1 or 2, wherein the step of selecting multiple reference stations is based on the proximity of the respective locations of each of the multiple reference stations to the approximate location of the mobile device. Clause 4: The method of Clause 1 or 2, wherein multiple reference stations are selected to minimize the distance between the midpoint or centroid of the reference station locations and the approximate location of the mobile device. Clause 5: The method of Clause 1, wherein the multiple reference stations are selected to maximize the number of common-view GNSS satellites between the mobile device and the multiple reference stations. Clause 6: The method of Clause 5, in order to maximize the number of common-view GNSS satellites between a mobile device and multiple reference stations, further comprising the steps of obtaining information from each of the multiple reference stations indicating GNSS satellites that can be seen by each of the reference stations, or obtaining information from the mobile device indicating GNSS satellites that can be seen by the mobile device, or both. Article 7: Any method of Articles 1 to 6, the step of selecting multiple reference stations, comprises the step of determining the number of reference stations to be included among the multiple reference stations. Clause 8: The method of Clause 7, wherein the number of reference stations is determined based on at least one of the following: quality of service (QoS), user requests from mobile devices, or applications on mobile devices. Clause 9: Any method of Clauses 1 to 8, the step of sending base station correction data to a mobile device, comprises the step of transmitting base station correction data from one or more mobile network base stations. Clause 10: The method of Clause 9, wherein the approximate location of a mobile device is within a first coverage area of ​​one or more mobile network base stations, and the method further comprises the step of sending base station correction data from a plurality of different base stations to a second mobile device in a second coverage area of ​​one or more mobile network base stations. Clause 11: A method for applying real-time kinematic (RTK) or differential global navigation system (DGNSS) corrections in a mobile device, the method comprising: acquiring base station correction data in the mobile device from each of a plurality of base stations, wherein for each base station, the base station correction data comprises one or more measurements obtained by a GNSS receiver at each base station; acquiring mobile device measurement data, wherein the mobile device measurement data comprises one or more measurements obtained by a GNSS receiver at the mobile device; and determining the position of the mobile device based on the base station correction data from each of the plurality of base stations and the mobile device measurement data. Clause 12: The method of Clause 11, the step of determining the location of a mobile device, comprises the steps of determining an estimated location of the mobile device for each of a plurality of reference stations based on reference station correction data from each reference station and mobile device measurement data, and determining the location of the mobile device based on the estimated location. Clause 13: The method of Clause 12, the step of determining the location of a mobile device based on estimated locations, comprises the step of taking a simple average or weighted average of at least some of the estimated locations. Clause 14: The method of Clause 11, the step of determining the location of a mobile device, comprises the step of using a single Kalman filter to process base station correction data from multiple base stations. Clause 15: A method according to any of Clauses 11-14, further comprising the step of verifying the accuracy of the determined position of a mobile device using carrier phase integer ambiguity or position vectors from at least two of a plurality of reference stations. Clause 16: The method of Clause 15, further comprising the steps of: ignoring base station correction data from one or more base stations among a plurality of base stations based on verification of the accuracy of the determined location of the mobile device; and determining the improved location of the mobile device based on the remaining base station correction data from the plurality of base stations and mobile device measurement data. Clause 17: The method of any of Clauses 11-16 further comprises the step of sending a request to the provider service for base station correction data. Clause 18: The method of Clause 17, wherein the request includes information indicating the approximate location of the mobile device. Clause 19: The method of Clause 17 or 18, wherein the requirement includes at least one of the following: Quality of Service (QOS) or the number of reference stations to be included among multiple reference stations. Clause 20: Any method of Clauses 11 to 19, the step of obtaining base station correction data from each of multiple base stations, comprises the step of receiving base station correction data from one or more mobile network base stations. Clause 21: The method of Clause 20, the step of receiving base station correction data from one or more mobile network base stations, comprises the step of repeatedly receiving base station correction data from one or more mobile network base stations. Clause 22: The method of Clause 21, wherein the repetition rate of receiving base station correction data is based on at least one of the following: the bandwidth of wireless communication with one or more mobile network base stations, or the performance requirements for determining the location of a mobile device. Clause 23: A computer server for providing reference station correction data to a mobile device for real-time kinematic (RTK) or differential global navigation satellite system (DGNSS) correction, the computer server comprising a transceiver, memory, and one or more processing units communicatively coupled to the transceiver and memory, wherein the one or more processing units are configured to receive information indicating the approximate location of the mobile device or information about satellite vehicles visible to the mobile device, to select a plurality of reference stations from which reference station correction data should be obtained, the selection being at least partially based on the approximate location of the mobile device or information about satellite vehicles visible to the mobile device, to obtain reference station correction data from each of the plurality of reference stations, for each reference station the reference station correction data comprising data based on one or more measurements obtained by a GNSS receiver at the respective reference station, and to send the reference station correction data to the mobile device via the transceiver. Clause 24: The computer server of Clause 23, wherein one or more processing units are further configured to select multiple base stations based on the respective locations of each of the multiple base stations. Clause 25: A computer server according to Clause 23 or 24, wherein one or more processing units are further configured to select a plurality of reference stations based on the proximity of the respective locations of each of the plurality of reference stations to the approximate location of a mobile device. Clause 26: A computer server according to Clause 23 or 24, wherein one or more processing units are configured to select a number of reference stations such that the distance between the midpoint or centroid of the reference station locations and the approximate location of the mobile device is minimized. Clause 27: The computer server of Clause 23, wherein one or more processing units are configured to select a number of reference stations to maximize the number of common-view GNSS satellites between the mobile device and the number of reference stations. Clause 28: The computer server of Clause 27 is configured such that, in order to maximize the number of common-view GNSS satellites between a mobile device and multiple reference stations, one or more processing units obtain information from each of the multiple reference stations indicating the GNSS satellites that can be seen by each reference station, or obtain information from the mobile device indicating the GNSS satellites that can be seen by the mobile device, or both. Clause 29: A computer server according to any of Clauses 23 to 28, wherein, in order to select multiple reference stations, one or more processing units are configured to determine the number of reference stations to be included among the multiple reference stations. Clause 30: The computer server of Clause 29, wherein one or more processing units are configured to determine the number of reference stations based on at least one of the following: quality of service (QoS), user requests from mobile devices, or applications from mobile devices. Clause 31: Any computer server specified in Clauses 23 to 30, wherein one or more processing units are configured to transmit base station correction data from one or more mobile network base stations in order to send base station correction data to mobile devices. Clause 32: In any computer server specified in Clauses 23 to 31, if the approximate location of a mobile device is within a first coverage area of ​​one or more mobile network base stations, one or more processing units are configured to send base station correction data from multiple different base stations to a second mobile device within a second coverage area of ​​one or more mobile network base stations. Clause 33: A mobile device for applying real-time kinematic (RTK) or differential global navigation system (DGNSS) correction, the mobile device comprising a transceiver, a GNSS receiver, memory, and one or more processing units communicatively coupled to the transceiver, GNSS receiver, and memory, wherein the one or more processing units are configured to acquire base station correction data from each of a plurality of base stations via the transceiver, wherein for each base station the base station correction data comprises one or more measurements obtained by the GNSS receiver at the respective base station; acquire mobile device measurement data, wherein the mobile device measurement data comprises one or more measurements obtained by the GNSS receiver of the mobile device; and determine the position of the mobile device based on the base station correction data from each of the plurality of base stations and the mobile device measurement data. Clause 34: A mobile device according to Clause 33, wherein, in order to determine the location of the mobile device, one or more processing units are configured to determine an estimated location of the mobile device for each of a plurality of reference stations based on reference station correction data from each reference station and mobile device measurement data, and to determine the location of the mobile device based on the estimated location. Clause 35: A mobile device according to Clause 34, wherein one or more processing units are configured to take a simple average or weighted average of at least some of the estimated positions in order to determine the position of the mobile device based on the estimated positions. Clause 36: A mobile device according to Clause 33, wherein, in order to determine the location of the mobile device, one or more processing units are configured to use a single Kalman filter to process base station correction data from multiple base stations. Clause 37: Any mobile device according to Clauses 33 to 36, wherein one or more processing units are further configured to verify the accuracy of the determined position of the mobile device using carrier phase integer ambiguity or position vectors from at least two of a plurality of reference stations. Clause 38: A mobile device according to Clause 37, wherein one or more processing units are further configured to ignore base station correction data from one or more base stations out of a plurality of base stations based on verification of the accuracy of the determined position of the mobile device, and to determine the improved position of the mobile device based on the remaining base station correction data from the plurality of base stations and mobile device measurement data. Clause 39: Any mobile device specified in Clauses 33-38, wherein one or more processing units are further configured to transmit requests for base station correction data to a provider service via a transceiver. Clause 40: A mobile device as defined in Clause 39, wherein one or more processing units are further configured to include in the request information indicating the approximate location of the mobile device. Clause 41: A mobile device of Clause 39 or 40, wherein one or more processing units are further configured to include in the request at least one of the following: quality of service (QoS) or the number of reference stations to be included among multiple reference stations. Clause 42: Any mobile device specified in Clauses 33 to 41, wherein one or more processing units are configured to receive base station correction data from one or more mobile network base stations in order to acquire base station correction data from each of multiple base stations. Clause 43: A mobile device as defined in Clause 42, wherein one or more processing units are configured to repeatedly receive base station correction data from one or more mobile network base stations in order to receive base station correction data from one or more mobile network base stations. Clause 44: The mobile device under Clause 43, whose repetition rate for receiving base station correction data is based on at least one of the following: the bandwidth of wireless communication with one or more mobile network base stations, or the performance requirements for determining the location of the mobile device. Clause 45: A device for providing reference station correction data to a mobile device for real-time kinematic (RTK) or differential global navigation satellite system (DGNSS) correction, the device comprising means for receiving information indicating the approximate location of the mobile device or information regarding satellite vehicles visible to the mobile device; means for selecting a plurality of reference stations from which reference station correction data should be obtained, wherein the selection is at least partially based on the approximate location of the mobile device or information regarding satellite vehicles visible to the mobile device; means for obtaining reference station correction data from each of the plurality of reference stations, wherein for each reference station the reference station correction data comprises data based on one or more measurements obtained by a GNSS receiver at the respective reference station; and means for sending the reference station correction data to the mobile device. Clause 46: The device of Clause 45, in which the selection of multiple base stations is additionally based on the respective location of each base station of the multiple base stations. Clause 47: For a device under Clause 45 or 46, the selection of multiple reference stations is based on the proximity of the respective locations of each reference station of the multiple reference stations to the approximate location of the mobile device. Clause 48: A device according to Clause 45 or 46, comprising means for selecting a plurality of reference stations, wherein means for selecting a plurality of reference stations such that the distance between the midpoint or centroid of the reference station locations and the approximate location of the mobile device is minimized. Clause 49: The device of Clause 45, which includes means for selecting a plurality of reference stations, comprises means for selecting a plurality of reference stations to maximize the number of common-view GNSS satellites between the mobile device and the plurality of reference stations. Clause 50: A device under Clause 49, further comprising means for obtaining information from each of the multiple reference stations indicating GNSS satellites that can be seen by each of the reference stations, or means for obtaining information from the mobile device indicating GNSS satellites that can be seen by the mobile device, or both, in order to maximize the number of common-view GNSS satellites between the mobile device and the multiple reference stations. Clause 51: Any device under Clauses 45 to 50, which includes means for selecting multiple base stations, comprises means for determining the number of base stations to be included among the multiple base stations. Clause 52: The number of reference stations in the devices of Clause 51 shall be determined based on at least one of the following: quality of service (QoS), user requests from mobile devices, or applications on mobile devices. Clause 53: Any device specified in Clauses 45 to 52, which provides means for sending base station correction data to a mobile device, comprises means for transmitting base station correction data from one or more mobile network base stations. Clause 54: A device for applying real-time kinematic (RTK) or differential global navigation system (DGNSS) corrections to a mobile device, the device comprising means for acquiring base station correction data from each of a plurality of base stations in the mobile device, wherein for each base station, the base station correction data comprises one or more measurements obtained by a GNSS receiver at each base station; means for acquiring mobile device measurement data, wherein the mobile device measurement data comprises one or more measurements obtained by a GNSS receiver at the mobile device; and means for determining the position of the mobile device based on the base station correction data from each of the plurality of base stations and the mobile device measurement data. Clause 55: The device of Clause 54, which includes means for determining the location of a mobile device, comprising means for determining the estimated location of a mobile device based on base station correction data from each of a plurality of base stations and mobile device measurement data, and means for determining the location of a mobile device based on the estimated location. Clause 56: The device of Clause 55, which includes means for determining the location of a mobile device based on estimated locations, comprising means for taking a simple average or weighted average of at least some of the estimated locations. Clause 57: The device of Clause 54, the means for determining the location of a mobile device, comprises means for using a single Kalman filter to process base station correction data from multiple base stations. Clause 58: Any device according to Clauses 54-57, further comprising means for verifying the accuracy of the determined position of a mobile device using carrier phase integer ambiguity or position vectors from at least two of a plurality of reference stations. Clause 59: The device of Clause 58 further comprising means for ignoring base station correction data from one or more base stations among a plurality of base stations based on verification of the accuracy of the determined location of the mobile device, and means for determining the improved location of the mobile device based on the remaining base station correction data from the plurality of base stations and mobile device measurement data. Clause 60: Any device specified in Clauses 54-59, further comprising means for transmitting a request for base station correction data to a provider service. Clause 61: A device according to Clause 60, further comprising means for including in the request information indicating the approximate location of a mobile device. Clause 62: A device of Clause 60 or 61 further comprising means for including in the requirements at least one of quality of service (QoS) or the number of reference stations to be included among a plurality of reference stations. Clause 63: A device according to any of Clauses 54 to 62, which includes means for obtaining base station correction data from each of a plurality of base stations, comprises means for receiving base station correction data from one or more mobile network base stations. Clause 64: The device of Clause 63, which includes means for receiving base station correction data from one or more mobile network base stations, comprises means for repeatedly receiving base station correction data from one or more mobile network base stations. Clause 65: A device under Clause 64 whose repetition rate for receiving base station correction data is based on at least one of the following: bandwidth for wireless communication with one or more mobile network base stations, or performance requirements for determining the location of a mobile device. Clause 66: A non-temporary computer-readable medium storing instructions for providing a mobile device with reference station correction data for real-time kinematic (RTK) or differential global navigation satellite system (DGNSS) correction, the instructions comprising: receiving information indicating the approximate location of the mobile device or information regarding satellite vehicles visible to the mobile device; selecting a plurality of reference stations from which reference station correction data should be obtained, the selection being at least partially based on the approximate location of the mobile device or information regarding satellite vehicles visible to the mobile device; obtaining reference station correction data from each of the plurality of reference stations, for each reference station the reference station correction data comprising data based on one or more measurements obtained by a GNSS receiver at the respective reference station; and a code for sending the reference station correction data to the mobile device. Clause 67: The non-temporary computer-readable medium of Clause 66, and the selection of multiple reference stations, is additionally based on the respective locations of each of the multiple reference stations. Clause 68: A non-temporary computer-readable medium under Clause 66 or 67, in which the selection of multiple reference stations is based on the proximity of the respective locations of each reference station of the multiple reference stations to the approximate location of the mobile device. Clause 69: A non-temporary computer-readable medium relating to Clause 66 or 67, comprising a code for selecting multiple reference stations, wherein the code for selecting multiple reference stations is such that the distance between the midpoint or centroid of the reference station locations and the approximate location of the mobile device is minimized. Clause 70: A non-temporary computer-readable medium of Clause 66, comprising a code for selecting multiple reference stations, wherein the code for selecting multiple reference stations maximizes the number of common-view GNSS satellites between the mobile device and the multiple reference stations. Clause 71: A non-temporary computer-readable medium of Clause 70, in order to maximize the number of common-view GNSS satellites between a mobile device and multiple reference stations, the instruction further comprises code for obtaining information from each reference station of multiple reference stations indicating GNSS satellites that can be seen by each reference station, or obtaining information from the mobile device indicating GNSS satellites that can be seen by the mobile device, or both. Article 72: A non-temporary computer-readable medium of any of Articles 66 to 71, wherein a code for selecting multiple reference stations comprises a code for determining the number of reference stations to be included among the multiple reference stations. Clause 73: The number of reference stations in the non-temporary computer-readable media of Clause 72 is determined based on at least one of the following: quality of service (QoS), user requests from mobile devices, or applications on mobile devices. Clause 74: A non-temporary computer-readable medium, any of the codes in Clauses 66-73, for sending base station correction data to a mobile device, comprises a code for transmitting base station correction data to one or more mobile network base stations. Clause 75: A non-temporary computer-readable medium for storing instructions for applying real-time kinematic (RTK) or differential global navigation satellite system (DGNSS) corrections on a mobile device, the instructions comprising a code for obtaining base station correction data on the mobile device from each of a plurality of base stations, wherein for each base station, the base station correction data comprises one or more measurements obtained by a GNSS receiver at the respective base station; obtaining mobile device measurement data, wherein the mobile device measurement data comprises one or more measurements obtained by a GNSS receiver at the mobile device; and determining the position of the mobile device based on the base station correction data from each of the plurality of base stations and the mobile device measurement data. Clause 76: A non-temporary computer-readable medium of Clause 75, comprising a code for determining the location of a mobile device, wherein for each of a plurality of reference stations, the code determines the estimated location of the mobile device based on reference station correction data from each reference station and mobile device measurement data, and determines the location of the mobile device based on the estimated location. Clause 77: A non-temporary computer-readable medium of Clause 76, which includes a code for determining the location of a mobile device based on estimated locations, comprising a code for taking a simple average or weighted average of at least some of the estimated locations. Clause 78: A non-temporary computer-readable medium of Clause 75, which includes a code for determining the location of a mobile device, comprises a code for using a single Kalman filter to process base station correction data from multiple base stations. Clause 79: A non-temporary computer-readable medium from any of Clauses 75-78, wherein the instruction further comprises code for verifying the accuracy of the determined position of a mobile device using carrier phase integer ambiguity or position vectors from at least two of a plurality of reference stations. Clause 80: A non-temporary computer-readable medium of Clause 79, wherein the instruction further comprises a code for determining the improved location of a mobile device, based on verification of the accuracy of the determined location of the mobile device, ignoring base station correction data from one or more base stations out of a plurality of base stations, and based on the remaining base station correction data from the plurality of base stations and mobile device measurement data. Clause 81: A non-temporary computer-readable medium from any of Clauses 75-80, wherein the instruction further comprises a code for transmitting a request for reference station correction data to a provider service. Clause 82: A non-temporary computer-readable medium of Clause 81, wherein the instruction further comprises a code for including in the request information indicating the approximate location of a mobile device. Clause 83: A non-temporary computer-readable medium relating to Clause 81 or 82, wherein the instruction further comprises a code for including in the request at least one of the following: quality of service (QoS) or the number of reference stations to be included among a plurality of reference stations. Clause 84: A non-temporary computer-readable medium from any of Clauses 75 to 83, comprising a code for obtaining base station correction data from each of a plurality of base stations, and including a code for receiving base station correction data from one or more mobile network base stations. Clause 85: A non-temporary computer-readable medium under Clause 84, comprising a code for receiving base station correction data from one or more mobile network base stations, includes a code for repeatedly receiving base station correction data from one or more mobile network base stations. Clause 86: The repetition rate of receiving base station correction data in a non-temporary computer-readable medium under Clause 85 is based on at least one of the following: bandwidth for wireless communication with one or more mobile network base stations, or performance requirements for determining the location of a mobile device. [Explanation of Symbols]

[0125] 100 RTK / DGNSS systems 110 Mobile Devices 110-1 First mobile device 110-2 Second mobile device 120 Reference station 130 Radio Frequency (RF) Signal 140 Satellite Vehicle (SV) 150 Data Communication Networks 160 baseline 170 service providers 210 Approximate mobile device location 230 radius 240 areas 320 distance 330 Center of gravity 340 Polygon 360 Center of gravity 505 Beam 505-1a First beam 505-1b Second beam 505-2a First beam 505-2b Second beam 520 cellular base stations 520-1 First base station 520-2 Second base station 540 areas 540-1 Area 1 540-2 Second Area 600-1 First Scheduling Method 600-2 Second Scheduling Method 600-3 Third Scheduling Method 600-4 The fourth scheduling method 1105 Bus 1110 Processing Unit 1115 Output Device 1120 Digital Signal Processor (DSP) 1130 Wireless communication interface 1132 Wireless Communication Antenna 1134 Wireless signal 1140 Sensor 1160 memory 1170 Input Devices 1180 GNSS receiver 1182 Antenna 1184 Signal 1200 Computer Systems 1205 Bus 1210 Processing Unit 1215 Input Devices 1220 Output Device 1225 Non-temporary storage devices 1230 Communication Subsystem 1233 Wireless communication interface 1235 Working memory 1240 Operating Systems 1245 Applications

Claims

1. A method for providing reference station correction data to a mobile device for real-time kinematic (RTK) or differential global navigation satellite system (DGNSS) correction, The steps include receiving information indicating the approximate location of the mobile device, or information regarding a satellite vehicle visible to the mobile device, The step of selecting a plurality of reference stations from which to obtain the aforementioned reference station correction data, The selection step is based at least partially on (i) the approximate location of the mobile device or the information relating to a satellite vehicle visible to the mobile device, and (ii) the respective locations of each of the multiple reference stations, wherein if three or more reference stations are selected, the multiple reference stations are selected to minimize the distance between the centroid of the polygon formed by the reference station locations of the selected reference stations and the approximate location of the mobile device. A step of acquiring base station correction data from each of the plurality of base stations, wherein for each of the base stations, the base station correction data comprises data based on one or more measurements obtained by a GNSS receiver at each of the base stations. The steps include sending the aforementioned base station correction data to the mobile device. A method for providing this.

2. The method according to claim 1, wherein the plurality of reference stations are selected to maximize the number of common-view GNSS satellites between the mobile device and the plurality of reference stations.

3. In order to maximize the number of common-view GNSS satellites between the mobile device and the plurality of reference stations, A step of obtaining information from each of the aforementioned multiple reference stations indicating the GNSS satellites that can be seen by each of the aforementioned reference stations, or A step of obtaining information from the mobile device indicating GNSS satellites that can be viewed by the mobile device, or Both The method according to claim 2, further comprising:

4. The method according to claim 1, wherein the step of selecting the plurality of reference stations comprises the step of determining the number of reference stations to be included among the plurality of reference stations.

5. The method according to claim 4, wherein the number of reference stations is determined based on at least one of quality of service (QOS), user requests from the mobile device, or applications on the mobile device.

6. The method according to claim 1, wherein the step of sending the base station correction data to the mobile device comprises the step of transmitting the base station correction data from one or more mobile network base stations.

7. The approximate location of the mobile device is within the first coverage area of ​​one or more mobile network base stations. The method according to claim 6, further comprising the step of sending base station correction data from a plurality of different base stations to a second mobile device in a second coverage area of ​​one or more mobile network base stations.

8. A computer server for providing reference station correction data to mobile devices for real-time kinematic (RTK) or differential global navigation satellite system (DGNSS) correction, Transceiver and, Memory and One or more processing units that are communicatively coupled to the transceiver and the memory. The system includes, and the one or more processing units, Receiving information indicating the approximate location of the mobile device, or information regarding a satellite vehicle visible to the mobile device, The selection of a plurality of reference stations from which the reference station correction data should be obtained, wherein the selection is based at least partially on (i) the approximate location of the mobile device or the information relating to a satellite vehicle visible to the mobile device, and (ii) the respective location of each of the plurality of reference stations, and if three or more reference stations are selected, the plurality of reference stations are selected such that the distance between the centroid of the polygon formed by the reference station locations of the selected reference stations and the approximate location of the mobile device is minimized. The method of obtaining the base station correction data from each of the aforementioned multiple base stations, wherein the base station correction data for each of the aforementioned base stations comprises data based on one or more measured values ​​obtained by a GNSS receiver at each of the aforementioned base stations. The aforementioned base station correction data is sent to the mobile device via the transceiver. A computer server configured to perform the following actions.

9. The computer server according to claim 8, further comprising means for carrying out the method described in any one of claims 2 to 7.

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