System, apparatus, and method for detecting flying objects

Abstract

A system and method for detecting and tracking a flying object are provided. The system includes a base station of a cellular system operably connected to a receiving antenna, configured to transmit and receive radio frequency (RF) signals that carry data according to a cellular communication standard protocol. The system also includes a radar station operably connected to a transmitting antenna, synchronized with the cellular communication standard protocol of the base station, which communicates with the radar station. The radar station is configured to: transmit radar RF signals on a selected frequency bandwidth of an uplink during a time window when the base station is in Uplink or not transmitting to detect a flying object, process RF signal data received by the base station's receiving antenna to identify a reflected signal from the flying object, and detect and track the flying object based on the reflected signal received.

Description

SYSTEM, APPARATUS, AND METHOD FOR DETECTING FLYING OBJECTSCROSS REFERENCE

[0001] This application claims the benefit of U.S. provisional application No. 63 / 712,088 filed October 25, 2024. The contents of this application is incorporated herein in its entirety.TECHNICAL FIELD

[0002] Embodiments described herein are generally related to the tracking and detection of flying objects using a combination of a radar system and a cellular system infrastructure.BACKGROUND ART

[0003] Air vehicles, such as Unmanned Aerial Vehicles (UAVs), including drones, pose a significant threat worldwide in many countries, regions, and arenas.

[0004] UAVs may fly at very low altitudes and low speeds, and their relatively small size often enables them to fly undetected. If the UAV or the UAVs are hostile, they may cause damage to infrastructure, the environment, and people, especially if the UAV is armed or built to explode.

[0005] Detection of such UAVs is a significant systemic problem, which involves sending warnings and their locations to air defense forces and the Aerial traffic authorities, to protect the country or other regions from damage by hostile UAVs.

[0006] Multiple antennas and Radio Frequency (RF) transmitters and receivers, e.g., RF transceivers, that may be deployed and spread as much as possible in many places, may add a high level of redundancy, survivability, robustness, and improve the detection capability of UAVs, and then identify each UAV as a foe, a hostile, or a friend UAV.

[0007] Thus, there is a significant need to track and detect UAVs.BRIEF DESCRIPTION OF THE DRAWING

[0008] Figure 1 illustrates a block diagram of a system for detecting and tracking a flying object in accordance with some demonstrative aspects.

[0009] Figure 2 illustrates a block diagram of an extension of the system of Figure 1 in accordance with some demonstrative aspects.

[0010] Figure 3 illustrates a flowchart of a method of a system of detecting and tracking a flying object in accordance with some demonstrative aspects.[Oil] Figure 4 illustrates a flowchart of a method performed by a Signal and Data Processor Unit (RSDPU) of a Radar station, according to some demonstrative aspects.

[0012] Figure 5 illustrates a flowchart of a method performed by a Central Data Processing Radar Surveillance Computer (CDPSC), according to some demonstrative aspects.

[0013] Figure 6 illustrates an interpolation of TX / RX beams based on some illustrative aspects.

[0014] Figure 7 illustrates transmitted signals by a linear array antenna, according to some demonstrative aspects.

[0015] Figure 8 illustrates TX / RX beams FoV, according to some demonstrative aspects.

[0016] Figure 9 illustrates a timing diagram of GAP symbols, according to some demonstrative aspects.

[0017] Figure 10 illustrates a table of Radar mode time slots / symbols allocation, according to some demonstrative aspects.BRIFF DESCRIPTION OF THE INVENTION

[0018] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of some embodiments. However, it may be understood by persons of ordinary skill in the art that some embodiments may be practiced without these specific details. In other instances, well-known methods, procedures, components, units, and / or circuits have not been described in detail so as not to obscure the discussion.

[0019] Discussions made herein utilizing terms, such as, for example, processing,” "computing,” "calculating,” "determining,” "establishing,” "analyzing,” "checking," or the like, may refer to operation(s) and / or process(es) of a computer, a computing platform, a computing system, an artificial intelligent (Al) systems using computing resources, that manipulate and / or transform data represented as physical (e.g., electronic) quantities within the computer's registers and / or memories into other data similarlyrepresented as physical quantities within the computer's registers and / or memories or other information storage medium that may store instructions to perform operations and / or processes.

[0020] The terms "plurality" and "a plurality," as used herein, include, for example, "multiple" or "two or more." For example, "a plurality of items" includes two or more items.

[0021] In some demonstrative embodiments, the present disclosure discloses an efficient and comprehensive method and system for detecting UAVs and other small or large aerial flying vehicles, such as aircraft, in many places with wide deployment of exist infrastructure.

[0022] For example, the system and method of the current disclosure may be highly efficient thanks to the wide deployment of the infrastructure and their strategic location of antenna and coverage general in high places with a wide Field Of View and overcome the limitations of current Radar systems. The current problem with these Radars is that they cannot always detect small-sized UAVs or track them along their flight path, for example, because of concealment or other detection problems, such as background noise from ground reflections (clutter) or other interfering objects in the Field Of View (FOV) on the ground, topographic concealment, such as, for example, by mountains or objects. These buildings limit the existing radar's field line of sight (LOS) visibility capabilities and these problems may cause difficulties in detecting such UAVs.

[0023] For example, the coverage area, angle of view (AOV), elevation, range, and altitude detection of the current radar antenna are usually limited. To increase detection capability, it is clear that as more Radar antenna units or elements cover a specific area or region, the detection coverage area may be improved, including in hidden and concealed air spaces and at low altitudes, without being limited to these conditions.

[0024] The current disclosure discloses the use of at least one standard cellular communication system infrastructure, which includes all the system elements required by a standard Radar system. Adding Radar functionality on top of the existing cellular network may require software adaptation and / or integration, with minor effects and / or losses to the existing cellular network. To work in a Radar mode, the system may beintegrated or designed to operate concurrently with its built-in original cellular mode of operation as a cellular communication system.

[0025] For example, activating the two operational modes may be implemented with minimal interference between the concurrent modes. The system may be optimally designed to minimize functional cellular losses, such as, for example, data rate, delay, data latency, and other capabilities and performance of the cellular system.

[0026] In some demonstrative aspects, in Radar mode, the system may use the transmitter and antenna of the base station (BS) and send radar pulses.

[0027] For example, the RF pulses may use selected frequency and / or frequencies during specified time intervals via its transmitter antenna and may use another or separate antenna of the base station for receiving the return echo pulses from the same object simultaneously.

[0028] For example, the system may require simultaneous activation of the transmitter and receiver. A functionality of transmission and reception of the pulses that may be required to start at the same time, or the start of the reception may be a very short time after the pulse or the pulse's transmission has started.

[0029] For example, the system's pulse transmission duty cycle may be very low, such as, for example, 10ms once a second. The pulses may be sent, for example, during the time between the uplink and downlink (Time Gap) of the cellular data Transmit (TX) and Receive (RX) time slots.

[0030] In some demonstrative aspects, in 5G cellular networks, for example, the transmitting and the receiving frequencies may be controlled by the cellular system software. The transmission and reception may be done at different frequencies simultaneously and / or at the same frequency, but not at the same time.

[0031] Changing the transmission and receiving frequencies that may be controlled by the system software to be identical at the same time, for example, in the 1800 MHz or even 26 GHz frequency band of 5G cellular networks, may enable a fast, efficient implementation of such a Radar mode.

[0032] In some demonstrative aspects, in cellular mode, the system may transmit on the Downlink (DL) and receive on the Uplink (UL) using different time slots, e.g., TimeDivision Duplex (TDD), or simultaneously using the same time slot with different frequencies, e.g., Frequency Division Duplex (FDD).

[0033] The two different operation modes of Radar mode and communication modes, both modes may be activated simultaneously, wherein the Radar mode activation may impose a very slight limit to degrade the cellular communication resources and capabilities of the cellular network system usage for data transmission, such as, for example, time or frequency slots, as well as other cellular system parameters.

[0034] For example, the standard cellular system may be used to transfer data, voice data, and other information, such as, for example, commands and control data or messages. According to one demonstrative aspect of the system, the cellular system may also provide an RF pulses or other signals that may be transmitted and / or received, for example, by the antenna of the base station (BS), wherein the received signals from the flying object, e.g., Unmaned Aerial Vehicle (UAV), may be received by the reception antenna that may be activated in FDD cellular mode, or a part of the antenna, for example, a group of elements of a phased array antenna, or by a separated reception Antenna in TDD cellular mode.

[0035] Cellular system types, or their versions or generations, may include 3GPP cellular standards such as, for example, 4G, 5G, 6G, or any other cellular systems, standard or nonstandard. The Antenna type may be omni, unidirectional, phased array antenna, static antenna, dynamic antenna, and / or any other kind of cellular antenna. For example, a phased array antenna may be called a smart antenna or a Multi Input Multi Output (MIMO) antenna and consists of an 2D array of elements, wherein each element may be used as a separate antenna.Phased Array antenna

[0036] Modem Radar uses the same type of phased-array antenna used in 5G cellular infrastructure and networks, so-called MIMO or smart antenna.

[0037] A phased array antenna may be built out of an array of small antenna elements, for example, a matrix with rows and columns, wherein an element, e.g., each element, in the matrix is considered as a single separated antenna. Combining the elements may radiate a very narrow RF beam using the beam-forming method, by controlling each element's transmission or reception signal phase to shape the beam width.

[0038] The beam may be dynamically steered in space, including scanning aerial spaces, while determining the line of sight and fields of view.

[0039] The phased array antenna, as it is used in this disclosure, may be segmented into any number of separate, independent antenna elements of variable size. Each antenna may consist of a group of elements, which may be split into separate groups for transmitting or receiving RF signals. For example, two or more groups may be defined for the same phased array antenna.

[0040] For example, the Phased array antenna consist of a group of 8x8 elements of total 64 elements then it is possible to split this array to two 4x8 elements each while one part is used as a transmission and the second may be used for reception, simultaneously at the same time, for identical and / or different frequencies wherein a synchronization may exists between the transmission and the receiving time of these two antenna that were split from the original 64 elements antenna.

[0041] For example, it may be possible to use two separate antennas, located adjacent to or distant from each other, with one for transmission and the other for reception.

[0042] With a phased-array antenna, it is possible to change the beam direction in azimuth and elevation (Beam steering) and select multiple groups of elements, each directed to a different tilt in elevation or azimuth, instead of scanning by physically moving the antenna.Radar mode of operation

[0043] In some aspects of a cellular communication system that works in radar mode, when the antenna transmitting (TX) the signal towards the flying object, e.g., a UAV, expected direction and / or location in the aerial space and the reception antenna (RX) is directed to the same direction, and receives the RF signal echo, e.g., reflected, from the flying object in the air such as, for example, from a UAV or any other aerial vehicle, e.g., an airplane.

[0044] The aerial coverage, as referred herein, is the covered aerial space of a group of adjacent Radars implemented by the antenna of the Base Stations (BS), which may enable maximum aerial coverage and cross coverage of air spaces. This capability of overlapping fields of view (FOV) may be supported by dynamic variable-angle beamsand FOVs, which maximize flying object detection while reducing or eliminating false alarms.

[0045] That significant benefit may be achieved by verifying a specific object using a few adjacent radar detections. That may, for example, be due to the beam-steering capability of the phased-array antennas of the different Radars implemented in different BSs.

[0046] In some demonstrative aspects, when a flying object, e.g., a target, is detected, beam steering may be used to narrow the FOV scanning angles to reduce the beam's scanned FOV or to increase antenna gain to focus on the flying object.

[0047] For example, one or more BSs and their antennas may detect or scan the flying object. Detection and tracking management coordinated between BSs may be implemented using additional dedicated computers or even the cellular network's computational power to improve the detection and tracking of at least one flying object.

[0048] Detection and tracking management coordinated across the different cellular systems, Base Stations (BS) and their cellular antenna may be implemented to improve the detection and tracking of at least one flying object. It may also be possible to use that capability with one or more antennas. For example, the antenna may be a distant relative to another antenna in the same area cell or in another cell with a cross line of sight, to see the flying object from different angles of view means each antenna may "see" air space differently from other antenna or may "see" the exact or partial aerial space, or the antenna of a cellular cell may cover the aerial space, from different directions or angles. In that case, more than one cellular antenna may probably "see" and detect the same object from various directions.

[0049] A triangulation method using at least two antennas may be used to provide a precise geographic location of the object in the airspace, assuming the locations of one or more antennas are known.

[0050] It should be understood that a cellular BS may support one or more antennas that may also work with the same frequency as the others.

[0051] For example, two antennas that cover different FOV with or without overlapping to cover different air spaces.

[0052] For example, the method implemented by the system may be used to measure the distance to the detected object by measuring the time difference between the RF TX pulse or signal start and the RX reception time, dividing by 2, and multiplying by the speed of light.

[0053] The RF frequency band may be defined and allocated for each different Radar, which may be implemented on each different BS. The frequency may differ from that of other nearby Radars wherein the selected frequency may be determined according the cellular BS operating frequency. That means that each Radar may use a different allocated RF frequency for its activity.

[0054] Another capability may be used to prevent interference in Radar mode between adjacent or all Radars that may interfere with each other.

[0055] It may be done by synchronizing these adjacent Radars; for example, GPS time synchronization may be implemented.

[0056] The synchronization may enable the activation of the Radar mode, such as, for example, the start time transmission of the signals by each cellular Base Station (BS), in a specific, defined time for each adj cent cell, or in a different antenna at the same time, or in a different cell.

[0057] Interference prevention between the antenna and receivers of adjacent BS or antenna may be achieved by transmitting different frequencies by each adjacent BS or adjacent transmitting or receiving antenna.Cellular systems transmission and reception operation mode

[0058] The cellular system transceivers may operate in Frequency Division Duplex (FDD) or Time Division Duplex (TDD) modes. FDD, which stands for Frequency Division Duplex (full duplex), and TDD, which stands for Time Division Duplex (half duplex), are both techniques for spectrum and time use. It is crucial that both duplex modes used for transmitting and receiving data links in mobile or fixed wireless broadband connections may occur simultaneously in both directions. In this scenario, data may flow downlink (DL) — toward the device, such as a mobile device, transceiver, or cellphone — and uplink (UL) — from the device — at the same time, with no noticeable interruptions.

[0059] FDD requires two separate frequency bands or channels. A sufficient frequency gap, such as 45 MHz, is necessary to separate the transmitting and receiving channels to prevent interference (full duplex). This gap, often called a "guard band," helps ensure clear and uninterrupted transmission while not affecting capacity. The frequency allocation for UL / DL capacity is predetermined based on system needs, making it the same in both directions. It is not possible to dynamically adjust this allocation capacity.

[0060] Continuous transmission and high performance are ensured with the FDD method of transmission and reception.

[0061] TDD systems utilize a single frequency band for both transmit and receive (half duplex). A system shares the same band and assigns alternating time slots for transmission and receive operations, separated by a time gap used as a "time guard". Any data transmitted could be 1 byte long or a frame of multiple bytes. Time slots may be dynamically allocated and vary in length based on network needs. A guard period is necessary to ensure that UL and DL transmissions do not collide. Swapping capacities in UL / DL degrades the network's performance.

[0062] Cellular system transceivers may operate in either FDD or TDD modes. For instance, TDD mode might be used for mobile devices close to the BS, while FDD mode could be applied to those farther away.Description of a Radar operation mode in FDD mode

[0063] In RADAR FDD mode, the transmit (TX) and receive (RX) are active simultaneously; in full-duplex mode, the same frequencies may be used.

[0064] The receiver down-converted data is the data obtained from ADC I / Q samples, which may be also used to detect a reflected RF Radar signals for performing a radar functions for detecting incoming aerial objects like UAVs.

[0065] For example, the required FDD change is to use the receiver frequency of the uplink data channel as the transmit frequency of the downlink data channel. In this mode, the Radar processing may implement pulse Doppler Radar functionality.Description of the Radar operation mode in TDD mode

[0066] In this mode, two separate antennas such as wide angle transmitting antenna for the Radar RF signals may be implemented. Such an antenna may be distant from the Cellular receiving antenna. Other Radar RF signals transmitting antenna may be thecellular phase array antenna made up of different sub-elements of the phased array (smart MIMO antenna). For example, the MIMO antenna might consist of 32x32 elements arranged on a one-square-meter panel.

[0067] The first part of the antenna group may be used for the TX, and the second part for the RX. Both antennas in this setup may be activated simultaneously at the same frequency.

[0068] To operate this mode, there may need to be control or configuration changes in the standard cellular infrastructure to enable simultaneous TX and RX on the same frequency.

[0069] The radar processing may use Frequency Modulation (FM), Continuous Wave (CW) — FM / CW types — or other ranging codes (similar to GPS Gold Codes or Zadoff-Chu), or Pulse Doppler radar functionality, or Holographic / staring Radar processing.

[0070] In some aspects, the Global Positioning System (GPS) is implemented using satellites, whose signals are detected by a receiver and a suitable GPS antenna to determine the geographical location or time.

[0071] Holographic Radar (Staring radar) processing is a type of radar that transmits a wide beam and receives the return signal using multiple narrow beams, where the combined angular field of view (FOV) of the narrow beams covers the entire width of the transmitted beam and its FOV.Radar performance

[0072] The following Radar equation may be used for estimating the detection range.SNR = Paverage X G transmitted X G reception X RCS x T coherent X nCG divided by (4xPI)3X R4X KT X NF*Loss Equation 1Where:SNR is the receiver Signal to Noise RatioPaverage is the Transmitter average PowerG transmitted is the transmitter antenna gain.G reception is the reception antenna GainRCS is the flying object Radar Cross SectionT coherent is the receiver coherent integration timenCG is the Non-Coherent GainPT is the constant of 3.1457R is the target RangeKT is Boltzmann constant times multiplied by the Temperature NF is the Receiver Noise FigureLoss is radar processing loss

[0073] For example, the calculation for P average of 1 Watt with RCS of 0.1 square meter suggests that the estimated detection range may be up to 4 kilometers.

[0074] Another example, calculation for Paverage of 1 Watt with RCS of 0.01 square meter shows that the estimated detection range may be up to 2 Kilometer.

[0075] For example, calculating the P average of 10 Watts with an RCS of 0.01 square meters, the estimated detection range may be up to 4 kilometers

[0076] The minimum SNR required for detection, for example, for Probability Detection (PD) of 90% is roughly 12- 15 dB.

[0077] Every 12 dB increase or decrease in SNR should increase or decrease the detection range by a factor of 2 accordingly.Frequencies and other timing parameters control, selection, and configuration

[0078] The latest generations, such as 4G, 5G, and newer, enable the configuration of most or all parameters of the cellular system through software using an Application Programming Interface (API).

[0079] The parameters may include frequencies, time intervals, pulses, frequency duration, bandwidth (BW), time slots, data frames or slots, cellular modes like FDD or TDD, and other system parameters.Description of Additional Hardware and Software

[0080] Additionally, modifications or any other changes or additions of units or elements such as a radar transmission antenna, processing units such as computers, fast links or any other devices to the cellular system software and hardware may be made to implement, activate, and enhance the cellular network system, as well as its capability to operate in Radar mode. The operational capability in both modes may be integrated and may function simultaneously while used for data communication, as originally intended. Activation in both modes may be added to existing cellular networks or integrated into future generations, allowing them to arrive with these features already included orembedded from the start. These adjustments may also be aimed at improving the system or enabling it to perform better, for example, by transmitting signals at higher power through the cellular system's internal resources or by adding an external transmitter synchronized with the system to activate transmission simultaneously with reception or detection at higher sensitivity. This may be done to improve signal-to-noise ratio (SNR) or other critical specifications of Radar mode activation. The goal is to enhance detection, lower detection thresholds, and reduce false alarms, as well as to enable better implementation or configuration of dual-mode operation as both a cellular network and a Radar system.Data on flying object acquisition, collection, and distribution in radar operation mode.

[0081] The received RF pulses or the echo signal returned from the object, including raw data that may be provided by the cellular system, may be processed by the cellular system resources or through additional processing capabilities. This includes extended processing of the signals, utilizing resources beyond the original cellular system infrastructure, such as an High Speed. Graphic Processor Unit (GPU) data center.

[0082] The received pulses or signals may be processed using advanced radar detection and tracking algorithms, such as Kalman fdters, along with any other processing performed by hardware components like electronic parts, circuits, boards, or processing units, and by software tools such as boards, computers, servers, or other processing devices based on either hardware or software, like GPUs.

[0083] An identification or classification of an object, which may also be called a flying object, may be defined based on an optimized threshold level to differentiate between true and false flying objects.

[0084] The identified flying object data and its detection parameters, which may include geographical location such as coordinates, direction, altitude, speed, intensity, size, significance, or other parameters, may be collected and stored in a database on a computer or server. This information may then be forwarded and distributed for various purposes, such as military or civilian traffic management and control, aerial traffic supervision, civil defense to issue warnings in specific regions, air defense, or any other need for this vital information.Other usage of dual-mode cellular and Radar system and method

[0085] The Radar mode system and method, implemented in a cellular communication network, detects or identifies flying objects using radar. It may determine parameters such as geographical coordinates, direction, altitude, speed, intensity, size, significance, or other factors. This system may be used for detection and tracking of both air and naval vessels.

[0086] All capabilities of the aerial radar detection and tracking system, according to that current invention, may also be useful for detection and tracking over the sea. For example, it may detect naval objects such as boats, vessels, and other maritime vehicles, as well as any other objects over the sea or laid over water bodies like lakes, or in enclosed seas or bays.

[0087] Artificial Intelligence (Al) implementation with Radar is combined with cellular systems or networks.

[0088] The number of BS and antennas deployed in a country or region may be quite large, sometimes even thousands or more. Similarly, during a hostile UAV attack, the number of hostile UAVs, including drones and other flying vehicles and objects, may also be very high.

[0089] For example, the amount of data provided may be very large and may need to be analyzed and summarized quickly to efficiently identify vital information. This includes data such as the types of UAVs, their levels of damage and potential risks, their numbers after filtering out false detections of multiple hostile UAVs from different detection radars to avoid incorrect counts, their possible destinations and velocities, and the identification of the most dangerous UAVs. It also involves distinguishing between friend or foe UAVs or other aerial vehicles, as well as recognizing any other UAVs or aerial vehicles that may appear in different locations and flying objects with the same or multiple objectives.

[0090] The Al machine may learn, for example, the type of UAVs by their "Radar signature" image of each UAV type received from different viewpoints, directions, and ranges, as well as according to their velocity, altitude, and other flight characteristics. This allows for the immediate provision of their performance data, such as maximumvelocity, maximum range, predicted destinations, flying objects, or any other vital information.

[0091] The "Radar signature" image of the UAVs may provide additional vital information and identification as well as other data relate to the UAV such as location, velocity altitude, trajectory and any other detected or tracking information based on data collected by the cellular network system or by its parts, which is also activated in Radar mode. These Al-driven capabilities could be applicable and suitable for any type of Radar, not necessarily limited to those that are fully implemented using cellular network infrastructure.Radar and Cellular system or network definition and description

[0092] Radar is a system that uses radio waves to measure the distance (range), direction (azimuth and elevation angles), and radial velocity of objects relative to the site. It is a radio-determination method used to detect and track aircraft, ships, spacecraft, guided missiles.

[0093] A cellular system or network, also called a mobile system or network, is a telecommunications network where connections to and from end nodes are wireless. The network is spread over land areas called cells, each covered by at least one fixed transceiver, such as a base station. These base stations provide coverage for the cell, allowing the transmission of voice, represented by data, data, and other content. For example, the cell uses a different set of frequencies from neighboring cells to prevent interference and ensure reliable service. Adding radar functionality on top of the existing widespread cellular network, as described here, may create a dual-mode network with extensive coverage for cities and countries.

[0094] When combined, these cells provide cellular radio coverage over a large area. This enables many portable transceivers (e.g., mobile phones, tablets, and laptops with mobile broadband modems, pagers, etc.) to communicate with each other and with fixed transceivers and telephones anywhere in the network through base stations. This remains true even if some transceivers move across multiple cells during transmission.

[0095] Embodiments of the system employ separate transmit and receive antennas with high isolation between them, allowing for simultaneous transmission and reception. The receiving antenna utilizes the existing cellular phased array antenna. The transmissionantenna is specially designed with very low side lobes in elevation. The Tx pulses are constantly synchronized with the existing symbol edges of the cellular system.

[0096] In case where there is no need for isolation between transmit and receive antenna, transmitting may be done by the cellular antenna.

[0097] This document describes a new radar system for detecting UAVs and other aerial objects by using the widespread cellular system and infrastructures, which offers very high coverage in dense urban areas and moderate coverage elsewhere.

[0098] The existing cellular base stations cover large areas, with many stations typically spaced about 500 meters apart in urban regions.

[0099] Applicant’s radar system utilizes the existing cellular infrastructure of 5G and 4G, mainly the smart phased array antenna, to receive reflected radar signals from a flying object using T / Rx I / Q down-converted data output from the T / Rx modules of the antenna elements.

[0100] The radar signal may be radiated, for example, through a dedicated cellular sector-wide beam antenna designed to provide coverage of the required 120 degrees in azimuth and approximately 30 degrees in elevation per sector field of view (FOV)

[0101] The radar signal may overlap with the existing 4G / 5G cellular signal in the frequency domain.

[0102] Both signals (radar and cellular) may be received simultaneously by the phased array antenna without interfering with cellular communication capabilities or performance, and may enable transparent, non-intrusive detection of radar flying objects.

[0103] Reference is made to Figure 8 for illustrative purposes. The three sectors of the base station, each equipped with a smart phased array antenna, may be used to generate narrow multi -receiving beams using Digital Beam Forming (DBF) in any direction within the angular Field of View (FOV), for example. A typical FOV of 120 degrees in azimuth and about 30 degrees in elevation may be achieved. Using three sectors per base station, this setup may provide coverage of approximately 360 degrees in azimuth and about 30 degrees in elevation.

[0104] This wide angular narrow multibeam receiving coverage results from the inherent ability of the smart phased array cellular antenna to generate multiple simultaneousnarrow receive beams using the DBF technique, supported by the cellular Distribution Unit (DU) / Radio Unit (RU).

[0105] Creating a narrow directed beam in reception (uplink) is achieved by multiplying the T / Rx I / Q data received from each of the m-by-n elements in the smart phased array cellular antenna by a specific precoding matrix of m*n phasors. This process is known as precoding.

[0106] Each precoding operation may produce specific beam I / Q data, defining a directed narrow beam within the field of view (FOV).

[0107] Many different precoding matrices may be applied to the same T / Rx EQ data collected from the antenna elements and Tx / Rx modules, resulting in multiple simultaneous narrow beams, each with its own calculated IQ data, covering together the entire FOV.

[0108] Each of the multi-beam I / Q data received may then be directed to a single radar signal processor that implements simultaneous multi-receiver beam radar detection.

[0109] The described system may transmit a radar signal through a dedicated, wide-beam antenna, which is separated from the cellular antenna of the Base Station and covers the entire FOV. The receiving antenna's beam is composed of multiple narrow beams (using DBF) that cover the FOV, and then processed by a single multi-radar receiver.

[0110] The above technique for wide beam transmission and simultaneous multiple narrow beam reception is known as staring (holographic) (non-scanning) radar.

[0111] The above process of generating a beam in a specific direction using precoding is called digital beamforming (DBF). generating a beam in a particular direction requires multiplying the T / Rx I / Q data by a precoding phasor matrix of size M*N. Applying multiple PRECODING matrices to the same T / Rx I / Q data may produce multiple narrow beams that may cover any field of view (FOV), typically 120x30 degrees per sector, or 360x30 degrees for all three sectors of a cellular base station. This process is known as digital beamforming (DBF). For example, the Nokia® antenna described above has 32 (4*8) T / Rx modules and, in future designs, may include 64 or even 128 T / Rx modules. The antenna has a gain of 25 dB and a beamwidth of 13 degrees in azimuth and 8 degrees in elevation at 3.5 GHz. To generate an FOV of 120 degrees in azimuth and 30 degrees inelevation, 24 beams (8x3) need to be created per sector, resulting in a total of 72 beams for all three sectors.

[0112] Each 5G base station consists of three main units as described below: a Radio Unit (RU) with a smart phased array antenna, usually controlled by a Distribution Unit (DU).

[0113] The 5G Central Unit (CU) implements the uppermost layer of the generic Base station (gNB), handling control-plane and user-plane functions, including mobility, security, and session management. The CU is connected to the distributed unit (DU) through a fiber optic interface. A fiber optic (FO) connection connects the RU / DU with the CU using the enhanced Common Public Radio Interface (eCPRI) protocol for data transfer.

[0114] New Unit: Radar Unit (RSDPU). For radar functionality, a separate radar transmitter, processor, and antenna may be added ( remark: in some cases transmission may be done via the cellular antenna). The transmission is synchronized with the cellular frames and is transmitted within the cellular frequency range.

[0115] A description of the structure of the cellular data frames and the way of interleaving the radar pulses in the cellular frames is described following.

[0116] The cellular data structure is made up of sequential (repeated) frames, each 10 milliseconds long, divided into 10 sub-frames of 1 millisecond each. Each sub-frame is further divided into a variable number of slots, depending on the cellular Sub Carrier Spacing (SCS).

[0117] The OFDM symbol duration depends on the SCS selected by the base station, which may be 15 kHz, 30 kHz, 60 kHz, or higher.

[0118] For example, SCS = 30 kHz, the slot duration is 500 microseconds, consisting of 14 symbols. Each symbol lasts approximately 35.7 microseconds (500 / 14 microseconds).

[0119] There are at least three types of symbols: uplink symbols, downlink symbols, and gap (idle) symbols (a part of the TDD special slot). Gap symbols are the symbols that separate downlink and uplink symbol blocks (as time spacing) in cellular TDD mode. There are no gap symbols in FDD.

[0120] In CP FDD mode, the transmission unit is configured to transmit during the prefix or suffix time of the data in the FDD uplink symbols, where the prefix data is discardedby the cellular receiver. The detection range is based on the transmission power and the portion of the time duration of a transmitted symbol.

[0121] In.

[0122] The radar transmitted stream pulses may operate in specific modes and during designated periods.

[0123] Remark: The CP width may use up to 7% of the symbol duration.

[0124] When SCS is 30 KHz, this equates to approximately 2.4 microseconds out of the total symbol duration of 35.7 microseconds.

[0125] Each radar transmitted pulse width may consume between 30% and 100% of the entire symbol duration, (up to 7% in CP modes).

[0126] Radar TX pulses are active only during the DWELL time window, which may last up to 200 milliseconds.

[0127] For example, a DWELL time of up to 200 milliseconds may used to collect received T / Rx EQ data of a reflected flying object signal stored in a DWELL buffer, and to perform DBF and radar signal processing for flying object detection up to 7 km.

[0128] The radar’s DWELL may be scheduled once per second or as often as once every T seconds (typically 5 seconds) or any other desired rate.

[0129] Note: DWELL may also activate at irregular rates (for example, on demand). Avoiding interference Between Nearby base-stations

[0130] The following techniques may be used to reduce inter-base-station interference caused by nearby radar transmitters antenna.- Schedule radar DWELLS in nearby base stations at different times (non-overlapping DWELLs).- Use different codes or modulation for the transmitters in nearby base stations, such as different chirp modulations or different pseudorandom codes (for example, different Gold codes, ZADOFF-CHU codes, or other UWB codes).- Select different radar modes for nearby base stations.

[0131] For example, in 5G systems, the uplink Tx power of each user equipment (UE) is controlled by the BS using special control channel signals to keep the received signal SNR at the base station (BS) below 20 dB. This UE power control is essential for cellularfunctionality and prevents interference from multiple UE signals received simultaneously at the BS antenna.

[0132] This causes 20 dB of interference to radar signals across all radar modes where the cellular and radar signals share overlapping spectrum, as follows:

[0133] Radar CP modes or (non-cooperative) Radar FDD / TDD modes.Avoiding interference in a base station example.

[0134] The interference issue in a base station happens because radar signals are sometimes transmitted and received at the same time, using the same frequency bandwidth. It is vital to minimize the coupling between the Tx radar antenna and the cellular reception antenna.Minimizing the coupling may be achieved in the following ways:1. Keeping the two antennas 1-2 meters apart.2. Possibly using isolation materials and appropriate structural mounting.3. Reducing the RF transmitter power (for example, to 10 dBm) to minimize leakage into the cellular antenna while maximizing radar performance in TDD / FDD modes.4. Selection of radar waveform involves choosing a Tx modulation that minimizes frequency coupling into the cellular OFDM symbols, typically using chirp signals or ultra-wideband signals such as random signals like gold codes Zadoff-Chuor other random codes with a flat spectrum.Calculated the required separation between the radar and cellular antenna (for different radar modes).

[0135] Calculating an example of the required isolation for the following five (out of 7) radar modes: gap mode, CP-TDD mode, CP-TDD mode, TDD cooperative mode, and FDD cooperative mode.

[0136] In the above 5 modes, there is no interference between radar and cellular systems. About 60 dB of isolation is necessary to prevent radar self-jamming caused by transmitter spectral FM noise leaking into the receiver antenna.Isolation required in Radar TDD and FDD (non-cooperative modes)

[0137] In these two modes, the radar transmission overlaps in time and frequency with the unlink data received by the cellular antenna. To prevent interference with the uplink cellular data, we need to use the following means, for example:1. Limiting the radar transmitted power, for example, to 10 dBm.2. Increasing the isolation between the radar and cellular antenna to about 100 db.

[0138] This may be achieved through about 2 meters of spatial separation and the addition of absorbing material. It is noted that in these modes, the radar detection range may be smaller than in other modes because of lower Tx power.

[0139] Remarks:1. GAP may be a block of 2-6 symbols (in TDD mode), separating the cellular DL from UL.2. CP may be about 7% cyclic prefix added to all cellular UL (or DL ) symbols, needed for proper cellular operation.Radar pulse allocation during DWELls example

[0140] Reference is made to Figure 10 for illustrative purposes. As previously mentioned, the radar transmission pulses are synchronized with cellular symbols. The duration of each radar pulse ranges may be from approximately 30% to 100% of a symbol's time, or up to 7% in CP modes

[0141] RADAR GAP MODE ===== a special slot TDD Gap dwell, radar: transmitting only during the TDD GAP symbols.

[0142] RADAR CP MODE ====== a DWELL in TDD / FDD uplink , radar transmitting during the narrow (up to 7%) CP part of all symbols.

[0143] RADAR TDD MODES ===== a TDD look up dwell, radar transmitting during all uplink and Gap symbols.

[0144] RADAR FDD MODES ====== a FDD look up dwell, radar transmitting during all uplink symbols.

[0145] REMARK: The equivalent Radar repetition rate in the GAP MODE may be , for example, 400 Hz (gap symbols every 2.5 milliseconds), while the equivalent radar repetition rate for the TDD MODE, FDD MODE, and CP MODE transmitted in all symbols during DWEL may be approximately 28 KHz (for cellular operating in 30 KHz SCS).Radar T / Rx T / Q data collection

[0146] For all radar modes, the radar transmitter is active only during DWELL time at the appropriate symbols based on the selected radar mode.

[0147] As previously described, for GAP mode, TDD mode, and FDD modes, the transmission may occur within 30% to 100% of the start of each symbol.

[0148] For RADAR CP mode, the transmission may only occur during the cyclic prefix (CP) interval, which may be about or up to 7% of a symbol's duration.

[0149] The IQ received data may fill the whole symbol period.

[0150] All the T / Rx I / Q symbols data from all the Tx / Rxs during dwell are transferred to a dwell buffer via a splitter connected to the fiber optic (FO) eCPRI link between DU and CU of the cellular units in the BS.

[0011] Another option (no optical sniffer) is to get the T / Rx EQ data directly from the CU or through another data interface.

[0152] The radar dwell data buffer might be stored in the local Radar Signal Processor (RDSPU).

[0153] Another option is to store the T / Rx IQ data in an external buffer (in a data center) where all radar processing may be done by GPUs in the data center.Radar signal processing flow example:

[0154] Select radar mode and wait for DWELL start command1. Start transmission with a stream of radar pulses for the DWELL duration.All radar transition pulses are synchronized to cellular symbols and are characterized by the selected radar mode (which is one 1 of 7 radar modes).2. Collect all the relevant received T / Rx symbols IQ data from the Tx / Rx units. Data is transferred via the optical CPRI / eCPRI link or directly from cellular CU and stored in the RDSPU(radar signal processing unit) dwell buffer.3. Perform DBF(digital beam forming) using a precoding matrix to generate one narrow beam specific T / Rx EQ data (in the FOV).4. Perform full RADAR signal processing, and store all detected flying objects details such as range, Doppler, angle, signal strength, etc, in a flying object buffer.5. Repeat Steps 3 and 4 to generate up to 72 narrow beams in the field of view, covering up to 360*30 degrees.

[0155] Send all detected flying objects to the central processing unit.Calculation of DWELL buffer size:

[0156] Following is an example for a Nokia® 32T / Rx’s units with 5G sub carrier spacing (scs) of 30 KHz1. Each symbol contains 4K T / Rx EQ frequency( or time ) samples of 4 bytes (2I / 2Q).2. There are 14 symbols per slot of 0.5 milliseconds.3. The number of bytes per symbol is equal to 4K*4B 16KB per symbol.Dwell I / Q buffer size table: An example for Nokia® 32 T / Rx antennaRadar mode # of bytes # of # # symbols 100 ms remarks per symbol symbols symbols per 100 ms DWELL for 32T / Rx per 2.5 ms per 10 DWELL Bufferms sizeDWEL L GAP TDD 32*4K*4= 2 8 80 40 MB0.5MBCP TDD- 0.5 MB 14+2=16 64 640 320 MBUL TDD 0.5MB 16 64 640 320MBFDD 0.5MB 70 280 2800 1.4GBRemark:

[0157] Storing dual polarization T / Rx I / Q data may require double memory and processing time. Computer processing time estimation for a 100-millisecond dwell. Range compression is performed on each symbol and is done in the frequency domain, requiring about 1.5 times the cost of a 4K FFT. Doppler processing occurs after range compression for each of the 4K range bins. The size of the Doppler FFT depends on the number of symbols per dwell and varies from mode to mode (80 to 4K). Assume 4K FFT execution time on an NVIDIA® A100 GPU is 0.1 microseconds. Signal processing may be performed locally or in a data center ($10 per 1 hour of A100 GPU usage).mode # # of range # doppler Total 1 beam 72 beams symbols 4K FFT fft 4K Processing processing per fft time time dwellgap 80 120 4K*fft(128) 248 24.8 1.78 ms (80*1.5) microsec1284K FFTCp-FDD 3K 4.5K 4KFFT(4K) 9.5K 950 68 msec microsecCp-TDD 560 840 4K*FFT 1.84K 184 13.2 msec (14*40) (560*1.5) (IK) microsecFFT(4K)FDD-UL 3K 4.5K 4K 8.5K 950microsec 68 msecTDD- 560 840 IK 1,84K 184 13.2 msec uplink microsecFDD-UL- 3K 4.5K 4K 8.5K 950microsec 68 msec cooperativeTDD- 560 840 IK 1,84K 184 13.2 msec uplink- microseccooperative

[0158] Remark:1. Using vertical and horizontal polarization T / Rx I / Q data may double the processing time.2. Execution time of digital beamforming for all 72 beams in the field of view using a tensor signal processor.

[0159] Using the Tensor Signal Processor (TSP) of 300 Tops on the A100 GPU takes less than 10 milliseconds to complete the digital beam forming for all 72 beams.

[0160] Radar processing in the data center price estimation example assumes a single Dwell processing time of 100 milliseconds and a $10 per-hour cost for either Al 00 or B200 usage in the data center.1 dwell Average dwell # of dwells Computation Price per processing rate processed per time per day daytime day And per For all FOV year0.1 sec 1 per 5 sec 16.8K 0.5 hour $5 per day $1500 per year

[0161] The estimated price is $1.5 K per year for a single BS radar functionality.Improving GAP mode velocity ambiguity

[0162] Reference is made to Figure 9 for illustrative purposes. GAP symbols are part of TDD mode used to separate downlink from uplink symbols. They are located in the cellular special slot, which is the 4th slot out of the five in the TDD group, and are repeated every 2.5 milliseconds.

[0163] The gap contains at least 2 adjacent symbols, with a maximum of 6.

[0164] The effective radar PRF in GAP mode is 400 Hertz, where at least 2 TX adjacent pulses (including even and odd symbols, are transmitted every 2.5 ms.

[0165] Reference is made to Figure 6 for illustrative purposes. The interpolation in azimuth or elevation may also be performed using state-of-the-art methods employed in monopulse radar or other statistical techniques, as follows:

[0166] 1D / 2D amplitude monopulse (in azimuth and elevation)

[0167] Interpolation factor = [abs(Sl) - abs(Saz)] / [abs(Sl) + abs(Saz)]

[0168] 1D / 2D phase monopulse (in azimuth and elevation)

[0169] Interpolation factor = Imaj(Sl - Saz) / Real(Sl - Saz)

[0170] Other 1D / 2D statistical methods include:

[0171] Enhancing flying object-acquisition angular (AoA) (accuracy with multiple narrow-beam antennas: Because we use a phased array, reflections from a flying object is present in several adjacent beams. We may leverage these multiple signals to improve angular precision. By understanding the beam patterns, we may create noiseless equations that relate the flying object's angles to the expected signal levels in each beam. Assuming these signals are affected by Gaussian noise whose second-order statistics are generated by the beamforming process, we model the angles (or their cosines or tangents) as parameters. The signals received from multiple beams form a Gaussian vector with a mean that is a known function of these parameters and a known covariance matrix. Themaximum likelihood estimator for the angles may then be found by solving a relatively simple optimization problem, possibly using numerical methods. If a prior distribution over the angles is available — such as from a previous snapshot, an MMSE estimator may be calculated.

[0172] Additionally, by incorporating assumptions about the flying object’s speed and acceleration, we may formulate a regularized estimation problem, for example with Kalman filtering or similar well-established techniques.

[0173] Low-power transmission of up to 10 dBm may be used only during the TDD and FDD uplink modes. This low-powered transmission ensures no interference with the cellular data link.Radar Tx antenna description example:

[0174] There is one Tx antenna per cellular sector. The antenna has a wide beamwidth of 120 degrees in azimuth and approximately 30 degrees in elevation above the horizon. Antenna side lobes at elevation below the horizon should be very low to reduce reflections from ground flying objects and clutter, decrease false alarms, and prevent blinding nearby BS antennas. The -3 dB point in elevation should be about 4- 6 degrees above the horizon, enabling detection of roughly 100m altitude flying objects at about 1 km distance.Optional antenna types:

[0175] Very low side-lobe antenna: may produce a 30-degree beam in elevation by using 2-3 linear array antennas with narrower beams, each ranging from 10-15 degrees. To do this, we may use two or three linear strip array antennas with vertical and / or horizontal polarization, or a combination of polarizations installed side by side or one on top of the other that together may cover the 30-degree elevation span - figure 7.

[0176] Another embodiment of the radar RF signal transmission may be done by using the phased array antenna or a section of the phased array antenna of the cellular Base Station.Friendly flying object augmentation

[0177] Friendly flight object geographical location data - position data as well as other flight parameters such as velocity, altitude, identification number or code may be displayed in the Control Center. Friendly Flying object GPS Data, including position,velocity, and time (PVT), may be forwarded to the nearest base stations. Remember that the friendly flying object is also detected by the radar. Comparing the friendly detector flying object radar data with its GPS data may be used to monitor radar performance, such as detection range and the accuracy of radar range, Doppler, and angle measurements and assist also to beam interpolation. The friendly fling object may send its position data and its other flight parameters via the cellular links to a flight control center, to a data cloud, or to an aerial vehicles management control center to be integrated as one object, merged with the detected and tracked friendly fling object by the radar.Flying object classification by on-site camera

[0178] Reference is made to Figure 6 for illustrative purposes. A flying object's angular location may be detected within a wide field of view using multibeam and thus obtain an angular position accuracy of 1 beam. In our case, for example, a 10 by 10 degree beam. The accuracy may be further improved by interpolating between adjacent beams, for example, using monopulse or other interpolation methods. This may give us an angular accuracy of 1 degree or better

[0179] With such precision, we may accurately aim and direct a day or night camera with zoom capability, achieving high angular accuracy and high-resolution images or videos of flying objects.

[0180] Using, for example, a 2-degree FOV zoomed camera with 4K resolution may result 0.01 milliradian resolution and cross-range flying object resolution of around 1 centimeter at a 1 km distance.

[0181] Installing such cameras in all base stations may enable viewing detected flying objects from multiple directions, i.e., creating a 3D picture or video of the flying objects as follows:

[0182] After the flying object is detected, other cameras in near base stations may be directed towards the same target to capture views from different angles and may generate a 3D visualization of the flying object. Additionally, all this output may be processed by Al or other methods for accurate classification.Additional features of combining camera, or Laser or Lidar, and radar DATA1. Except for flying object classification, there is also an option to perform optical tracking assisted by radar cueing (auxiliary) data., 2. Use the inherently accurate optical angular measurement to calibrate and improve the mono pulse interpolation3. Use the extra precision AOA from the camera, for on site laser beam, or Lidar to direct external systems like laser weapons or jammers, and other devices towards the flying object.4. Use the inherently accurate RCS according to the known RCS of a friendly target. SYSTEM DATA CONTROL CENTER DESCRIPTION

[0183] This center receives information from multiple base stations, including all flying objects' range, Doppler angle of arrival, Signal Noise Ratio (SNR), time tag and video / photo (if available) of flying objects from BS cameras, as well as other parameters.

[0184] The information may supplied during or after each dwell (typically every few seconds). The CDPSC may perform the following examples:1. Determine the flying object location and the flying object velocity vector using triangulation or other methods using at least two base stations.2. Use a video picture to perform flying object identification and classification.3. Create a 3D picture of the flying object.4. Perform dwell-to-dwell Track while scan (TWS) using state-of-the-art processing, including Kalman filtering, to maintain and update multiple flying object tracks to be displayed on a map representation illustrating the trajectory of all flying objects, including friendly flying objects.5. Send information about flying objects to external ATC (Air Traffic Control). 6. Use Al for identification and classification or improved performance.7. Using a friendly cooperative UAV such as a multi copter drone where its is transmitted, at least its position data may enable to precisely calibrate the radar AOA, RCS and other parameters as a target by using the inherent accurate optical angular measurement to calibrate the mono-pulse interpolation of the radar or using the optical angle to direct external systems like laser weapon or jammers and other devices towards the target.8. Perform radar background monitoring of radar performance that may include the radar accuracies of range, velocity or an Angle of Arrival.System parameters summary table (example).parameter detailsDwell time Any rate, (typically once every 5 seconds)Dwell rate Variable or any rate typically one per 5 secTx width 0- 100% radar mode dependentTX power Up to 20W radar mode dependentTx BW 0-100 MHzTx modulation Variable Chirp ,Gold , Zadoff-Chu or random PN sequences BS toBS Near base stations may have non-overlapping dwell, Different interference waveforms and slightly different center frequencies from mitigation neighboring BSMax FOV Up to 360*30 degreeMax # beams in Depending on 5GRF frequency and 5GMIM0 antennaFOV design (0-72 in our example )(Using DBF)Angular Improved by using beam interpolation by a factor of 10accuracy depending on target SNR

[0185] References to "one embodiment,” "an embodiment,” "demonstrative embodiment,” "various embodiments," etc., indicate that the embodiment(s) so described may include a particular feature, structure, or characteristic, but not every embodiment necessarily includes the particular feature, structure, or characteristic. Further, repeated use of the phrase "in one demonstrative embodiment" does not necessarily refer to the same embodiment, although it may.

[0186] As used herein, unless otherwise specified, the use of the ordinal adjectives "first,” "second,” "third," etc., to describe a common object merely indicates that different instances of like objects are being referred to and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or any other manner.

[0187] Reference is first made to Figures 1 and 2, which illustrate a block diagram of a system for detecting and tracking a flying object 110 in accordance with some demonstrative embodiments.

[0188] In some demonstrative aspects, a system 100 (Figure 1) for detecting and tracking a flying object 110 may include a base station 120 of a cellular system operably coupled to a receiving antenna 130 and configured to transmit and receive radio frequency (RF) signals which carry data according to a cellular communication standard protocol.

[0189] For example, the cellular communication standard protocol may include at least one of the 3GPP standards, such as, for example, 5G, or further generation, or any other standard, if desired.

[0190] In some demonstrative aspects, system 100 may include a radar station 140 operably coupled to a transmitting antenna 150 and synchronized with the cellular communication standard protocol of base station 120, using modem 146 which is in communication with radar station 140 or provided from the Base Station.

[0191] In some demonstrative aspects, the radar station 140 may transmit radar RF signals 160 on a selected frequency bandwidth of an uplink during a time window when the base station 120 in Up-Link or not transmitting to detect the flying object 110. For example, the radar station 140 may include a radar transmitter (TX) unit 142, a Radar Signal and Data Processor Unit (RSDPU) 144, and a cellular modem 146 for synchronization.

[0192] In some demonstrative aspects, the radar station 140 may use RSDPU 144 to process RF signal data received by the receiving antenna 130 of the base station 120 to detect a reflected signal 170 returned from the flying object 110 and to detect and track the flying object 110 based on the reflected signal 170.

[0193] In some demonstrative aspects, RSDPU 144 may be configured to: receive In-phase / Quadrature-phase (I / Q) data symbols 270 (Figure 2) from the cellular Radio modem 146 operably coupled to the receiving antenna 130, process the received T / Rx I / Q data symbols, and may provide a detection and tracking signal based on the reflected signal 170 from the flying object 110 to a data center (not shown).

[0194] In one aspect, when switch 148 is switched to cellular modem 146, cellular modem 146 may be configured to communicate with base station 120 and may receive synchronization data signal 270 to time and frequency synchronization of radar station 140 with the cellular data of base station 120.

[0195] Advantageously, using cellular modem 146 for providing the synchronization data signal eliminates the need for a physical connection to base station 120 in order to provide this signal.

[0196] In another demonstrative aspect, base station 120 may include a Distribution Unit (DU) 122, which is connected via, for example, an optical link 126, to a central unit (CU)124 and to the receiving antenna 130. For example, switches 149 may be used to connect CU 124 to RSDPU 144 and to transfer T / Rx I / Q data to RSDPU 144.

[0197] In another demonstrative aspect, switch 149 may connect an optical sniffer 128 to RSDPU 144. For example, the optical sniffer 124 may be connected to the optical link 126 to transfer the T / Rx I / Q data to the RSDPU 144.

[0198] In some illustrative aspects of the present disclosure, RSDPU 144 may be configured to calibrate the RCS according to the known RCS of a friendly target or the angular interpolation parameters of an Angle of Arrival (AoA) according to the accuracy of the AoA derived from a captured video of the flying object by a camera 190 operably coupled to radar station 140.

[0199] For example, base station 120 may be configured to provide power to RU 121, DU 122, and radar station 140.

[0200] In some demonstrative aspects, the cellular base station 120 may be configured to function as a STARING / HOLOGRAPHIC Radar operating concurrently and simultaneously with radar Tx without interfering with the designated operation of the base station 120 in the cellular network for communication with cellular devices.

[0201] In some demonstrative aspects, the radar station 140 may be configured to transmit a stream of pulses in a constant, predetermined sequence, with the transmission limited to no more than 200 milliseconds, which is a DWELL time.

[0202] In some demonstrative aspects, the transmitting antenna 160 may include one or more Horn antennas, one or more linear phased array antennas or any other types of radar antennas.

[0203] In some illustrative aspects of the present disclosure, the transmitting antenna 150 may include one or more linear phased array antennas comprise one or more antenna elements, wherein the one or more linear phased array antennas are mounted adjacently or above each other and use different elevation shifting of a beam center to cover together a required elevation in a sector, wherein a linear phased array antenna of the linear phased array antennas has a predetermined polarization, and the beam of the linear phased array antenna near the horizon is amplitude tapered to produce very low side lobes in the horizon direction, and pre-defined above the horizon.

[0204] In some demonstrative aspects, the radar station 140 may include an application (Fig 9) configured to: resolve the Doppler ambiguity in the GAP TDD mode caused by a low Pulse Repetition Frequency (PRF) by processing even and odd Tx symbols streams separately, calculate the phase difference between the signals detected in the even and odd sequences, and may resolve the flying object Doppler ambiguity based on the calculated phase difference.

[0205] In some demonstrative aspects, the Tx pulse width may be determined according to the radar mode selected from: A GAP TDD mode, a Time Division Duplex (TDD) mode, a Cooperative Time Division Duplex (TDD) mode, a Cyclic Prefix (CP) TDD mode, a Frequency Division Duplex (FDD) mode, a Cooperative Frequency Division Duplex (FDD), and a CP FDD mode.

[0206] The cellular data structure consists of sequential (repeated) frames, each 10 milliseconds long, divided into 10 sub-frames of 1 millisecond each. Each sub-frame is further divided into a variable number of slots, depending on the cellular Sub Carrier Spacing (SCS).

[0207] The duration of the OFDM symbol 270 (Figure 2) depends on the SCS chosen by the base station 140, which may be 15 kHz, 30 kHz, 60 kHz, or higher.

[0208] For SCS = 30 kHz, the slot duration is 500 microseconds, consisting of 14 symbols. Each symbol lasts approximately 35.7 microseconds (500 / 14 microseconds).

[0209] For example, there may be three types of symbols: uplink symbols, downlink symbols, and gap (idle) symbols (a part of the special slot). Gap symbols are the symbols that separate downlink and uplink symbol blocks (as time spacing) in cellular TDD mode. It should be understood that there are no gap symbols in FDD.

[0210] For example, in CP FDD mode, the transmission unit is configured to transmit during the prefix or suffix time of FDD uplink symbols, where the cellular receiver discards the prefix data. The detection range is based on the transmission power and the portion of the symbol duration during which the signal is transmitted. (up to 7%)

[0211] Table 1 below provides information on the Radar transmission pulse parameters according to modes (as an example):Mode Description Tx Tx Cellular Remarks power percentage Bandwidthof symbol usage byRadarGAP Transmit Up to 43 30%-100% Up to 100%during TDD dBm from start of2-6 Gap symbolsymbolsCP -TDD Transmit Up to 43 7% at end of Up to 100% This 7%during 7% of dBm symbol is all uplink discarded symbols bycellular receiver CP-FDD Transmit Up to 43 7% at end of Up to 100% This 7%during all dBm symbol is uplink discarded symbols bycellular receiver TDD Transmit 10 dBm 30%- Up to 100%during all 100%fromuplink start ofsymbols symbolFDD Transmit 10 dBm 30%-100% Up to 100%during all from start ofuplink symbolsymbolsTDD Transmit 43 dBm 30%-100% up to 50%cooperative during all from start of allocateduplink symbol for radarsymbols onlyFDD- Transmit 43 dBm 30%-100% up to 50%cooperative during all from start of allocateduplink symbol for radarsymbols onlyTable 1Table 2 below provides radar-transmitting parameters for different cellular 5G modes.# Cellular Tx Tx % Cooperative Tx Estimated cellular mode pulse Of mode power detection spectral location symbol range usage1 Gap TDD 2-6 Gap 30- No 43 dBm 3 Km 100%symbol 100% (20W) common withcellular2 CP TDD all UL Up to No 43 dBm IKm 100% symbols 7% common with cellular 3 CP FDD all UL Up to No 43 dBm 1.5Km 100%symbols 7% common with cellular 4 TDD all UL 30- No lOdBm up to 500 100%symbols 100% m common with cellular 5 FDD all UL 30- No lOdBm up to 500symbols 100% m6 Cooperative all UL 30- Yes 43 dBm 4.5Km Cooperative TDD symbols 100% Needs BW get up to allocation 50% of cellular BW 7 Cooperative all UL 30- Yes 43 dBm 7Km Cooperative FDD symbols 100% Needs BW getup to allocation 50% ofcellular BW Table 2

[0212] The radar transmitted pulses may operate in specific modes and during designated periods.

[0213] Remark: The CP width uses up to 7% of the symbol time.

[0214] When SCS is 30 KHz, this equates to approximately 2.4 microseconds out of the total symbol duration of 35.7 microseconds.

[0215] Each radar-transmitted pulse consumes between 30% and 100% of the symbol duration.

[0216] Radar TX pulses are active only during the DWELL time window, which may last up to 200

[0217] For example, a DWELL time of up to 200 milliseconds may be used to collect received T / Rx EQ data of a reflected flying object signal stored in a DWELL buffer, and to perform digital beam forming (DBF) and radar signal processing for flying object detection up to 7 km.

[0218] The radar’s DWELL may be scheduled at any rate for example once per second or, once per 5 seconds.Note: DWELL may also activate at irregular rates, for example, on demand.DETAILD DESCRIPTION OF THE INVENTION

[0219] In some demonstrative aspects of the present disclosure, the receiving antenna 130 may include a phased array antenna, and T / Rx I / Q symbol data from one or more transmission and reception elements (Tx / Rx) of the phased array antenna are received and transported via optical link 126 to CU. The optical link 126 may be operably coupled to the DU 122 and CU 124. For example, DU 122 may transfer the T / Rx EQ symbols from the phased array antenna to CU 124. For example, the CU 124 may be configured to transfer the T / Rx I / Q symbols and synchronization data to the radar station 140.

[0220] Furthermore, RSDPU 144 may be configured to perform Digital Beam Forming (DBF) using Tx / Rx I / Q symbol data to generate multiple narrow beams. For example, the generated beams have similar angular gain patterns and overlap with neighboring beams, in both azimuth and elevation, this overlap is used to provide sub-beam (intra- beam), angular accuracy of at least 1 or 2 degrees. The sub-beam angular accuracy may be achieved by combining the flying object data within the beam with signals from the flying object in neighboring beams, in both azimuth and elevation.

[0221] In some demonstrative aspects of the present disclosure, the flying object 110 may include at least one of an Unmanned Aerial Vehicle (UAV), a manned aerial vehicle, an airplane, a helicopter, or a flying object.

[0222] In some illustrative aspects of the present disclosure, system 100 may further include a Central Data Processing Radar Surveillance Computer (CDPSC) 180, and at least two cellular neighboring base stations configured to send detected flying object data to the CDPSC 180. For example, CDPSC 180 may be configured to determine the location and a velocity vector of the flying object, merge the data of the flying object received from at least two neighboring base stations to determine and identify that the flying object data matches the flying object data detected by the at least two cellular neighboring base stations, provide a first aerial image of a geographical location of the flying object received from the at least two cellular neighboring base stations, provide a second aerial image of at least one flying object 110 with a route of the flying object on the first aerial image.

[0223] A software application 250 (Figure 2) may be configured to display at least one detected flying object on a screen 260 (Figure 2), send at least in part the geographical location of the detected flying object, a velocity, a direction, an altitude, a Radar Cross Section (RCS) size, and any other parameters of the flying object 110 to the CDPSC 180 or to an Aerial Traffic Control Center (ATC) 185 or to any other destination, and gather the geographical location and other parameters of the detected flying object 110 from the two or more neighboring base stations 220 and 230 (Figure 2), convert at least in part the parameters, integrate the converted parameters, and create a map that illustrates the trajectory of the flying object 110, which visualizes the flight path of the flying object 110.

[0224] In some illustrative aspects of the present disclosure, system 100 may further include a camera 190, which may be directed by cueing radar data toward the detected flying object. The camera 190 may send the captured video / photo to RDSPU / CDPSC to perform flying object identification, classification, and optical tracking of images and video of the detected flying object 110 and submit the information to the CDPSC 180 for flying object classification, wherein the CDPSC 180 may send the flying object video and data to the CDPSC 180 or to the ATC 185 via a data link that may comprises a data link 183.

[0225] The information related to the flying object 110 may be shared and transferred between two or more base stations 220 and 230 and the CDPSC 180 via a data link, wherein the data link comprises at least one of a cellular data link, an internet network, data clouds or the like.

[0226] For example, the geographical location of the flying object, which is derived from the Base Station (BS) radar measurement, is sent to at least one other base station for directing the camera 190 towards a detected flying object to generate an image and a video of a different view of the detected flying object 110 for classification of the flying object 110.

[0227] In some illustrative aspects of the present disclosure, the camera 190 may provide a high-accuracy AoA derived from a radar location detection of the flying object 110 and configured to provide a geographical location of the flying object 110 based on the AoAand a range of the flying object, wherein a detected geographical location of the flying object is distributed to at least one other base station.

[0228] In some illustrative aspects of the present disclosure, at least one friendly flying object 210 (Figure 2) may be configured to share and report a geographical location, an identity, and flight information with the CDPSC 180. For example, CDPSC 180 may be configured to: integrate and merge the parameters of friendly flying objects, and to represent the identified friendly flying object and an unidentified flying object in an aerial map by illustrating a geographical location, a route, a trajectory of the identified friendly flying object 210, and the unidentified flying object, e.g., flying object 110.

[0229] In some illustrative aspects of the present disclosure, the classification of the flying object 110 may be done by using Artificial Intelligence (Al).

[0230] Reference is now made to Figure 3, which illustrates a flowchart of a method 300 for detecting and tracking a flying object in accordance with some demonstrative embodiments.

[0231] In some illustrative aspects of the present disclosure, the method may include synchronizing the radar station 140 (Figure 1) with a cellular communication standard protocol of a cellular base station 120 (Figure 1), which is in communication with the radar station 140 (Figure 1), as shown in text box 3 lOusing for example modem 146.

[0232] The radar station 140 may transmit by a transmitting antenna 130 (Figure 1) of the radar station 140 radio frequency (RF) signals on a selected frequency bandwidth of an uplink 161 (Figure 1) during a time window when the base station is in Uplink or not transmitting to detect a flying object 110 (Figure 1), as shown in text box 320.

[0233] The receiving antenna 130 (Figure 1) of the base station 120 may receive RF signals that may communicate with cellular apparatus or carry data according to the cellular communication standard protocol as well as the radar RF signals , as shown in text box 330.

[0234] The data received by the receiving antenna 130 of the base station 120 may be processed to detect a reflected signal returned from the flying object, as shown in text box 230, and to detect and track the flying object based on the detected reflected signal, as shown in text box 350

[0235] For example, transmitting in a predetermined sequence a stream of pulses, wherein the transmission of the stream of pulses is time-limited to no more than 200 milliseconds, which is a DWELL time.

[0236] For example, determining radar Tx pulse width according to the cellular transmission mode selected from: A GAP TDD mode, a Time Division Duplex (TDD) mode, a Cooperative Time Division Duplex (TDD) mode, a Cyclic Prefix (CP) TDD mode, a Frequency Division Duplex (FDD) mode, a Cooperative Frequency Division Duplex (FDD), and a CP FDD mode.

[0237] For example performing a Digital Beam Forming (DBF) by using the T / Rx I / Q symbol data to generate multiple narrow beams covering the whole FOV, wherein the generated beams have similar angular gain patterns and an angular overlap with neighboring beams, in azimuth and elevation, and are used to provide sub-beam angular accuracy of at least 1 or 2 degrees, by combining the flying object data in the beam with signals of the flying object in neighboring beams, in azimuth and elevation, to achieve the sub-beam angular accuracy.

[0238] Reference is now made to Figure 4, which illustrates a flowchart of a method performed by a Signal and Data Processor Unit (RSDPU) 144 (Figure 1) of the Radar station 140 (Figure 1), according to some demonstrative aspects.

[0239] In some demonstrative aspects, the RSDPU may receive from a cellular Radio Unit (RU) 121 (Figure 1) and a Distribution Unit (DU) 122 (Figure 1) that are operably coupled to the receiving antenna In-phase / Quadrature-phase T / Rx (I / Q) data symbols, as shown in text box 410.

[0240] The RSDPU 144 may process the received T / Rx I / Q data symbols, as in text box 330, as shown in text box 420, and may provide a detection and tracking signal based on the reflected signal from the flying object 110 (Figure 1), as shown in text box 430.

[0241] Reference is now made to Figure 5, which illustrates a flowchart of a method 400 performed by a Central Data Processing Radar Surveillance Computer (CDPSC)180 (Figure 1), according to some demonstrative aspects.

[0242] In some demonstrative aspects, the system 100 (Figure 1) further includes at least two cellular base stations configured to send detected flying object data to CDPSC 180. CDPSC 180 may employ the following method 500.

[0243] Tn some demonstrative aspects, the method may start with merging the flying object data received from at least two neighboring base stations to determine and identify the flying object data that matches the flying object data the base station detected, as shown in text box 510.

[0244] The method proceeds with determining the corrected location and a velocity vector of the flying object, as shown in text box 520

[0245] Providing a data of first aerial picture as an aerial map of a geographical location of the flying object that was received from the base station, as shown in text box 530

[0246] Providing a data of second aerial picture of at least one flying object with a route of the flying object on the first aerial picture, as shown in text box 540.

[0247] Providing data for aerial map displaying using a software application that is configured to provide data for display at least one detected flying object on a display, send at least in part the geographical location of the detected flying object, a velocity, a direction, an altitude, a radar area size, and any other parameters of the flying object to an Aerial Traffic Control Center (ATC), as shown in text box 550.

[0248] The method may end with receiving and collecting the geographical location and the other parameters of the detected flying object from the two or more base stations, converting at least part of the parameters, integrating, and converting into a map representation illustrating the trajectory of the flying object that visualizes the flight path of the flying object, as shown in text box 560.

[0249] In some demonstrative aspects, the CDPSC may be configured to classify the flying object based on flying object identification, classification, and optical tracking of images and video of the detected flying object provided from a camera; and sending the flying object video and data to the ATC via a data link that uses a cellular data connection.

[0250] A method to process radar signals, which may be performed by RSDPU offline in a data center using a data center GPU. This may be done by sending the Dwell Tx / Rx IQ dwell memory block / for offline processing, as it described at paragraph

[0154] above.

[0251] Another demonstration aspect where all radar functionality may be implemented and performed in an external data center High Speed GPU Computer (HPC) data centerthat may include a Graphical Processing Unit (GPU) which uses the T / Rx IQ Dwell memory buffer that may be transferred to the high speed GPU Data center

[0252] In some demonstrative aspects of the present disclosure, sea / naval targets may be detected by installing an additional transmitting antenna pointing toward the ground.

[0253] The terminology used herein is to describe particular embodiments only and is not intended to be limiting the invention. As used herein, the singular forms "a,” "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It may be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0254] Also, the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of "including,” "comprising," or "having,” "containing,” "involving," and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.

[0255] The subject matter described above is provided by way of illustration only and should not be construed as limiting. Various modifications and changes may be made to the subject matter described herein without following the example embodiments and applications illustrated and described and without departing from the true spirit and scope of the present invention, which is set forth in the following claims.

Claims

CLAIMSWhat is claimed is:

1. A system for detecting and tracking a flying object comprising:a base station of a cellular system operably coupled to a receiving antenna and configured to transmit and receive radio frequency (RF) signals which communicate data according to a cellular communication standard protocol;a radar station operably coupled to a transmitting antenna and synchronized in frequency and time according the cellular communication standard protocol of the base station, which is in communication with the radar station, and configured to:transmit radar RF signals on a selected frequency bandwidth of an uplink during a time window when the base station is in Uplink or not transmitting, to detect a flying object;process RF signal data received by the receiving antenna of the base station to detect a reflected signal returned from the flying object; and detect and track the flying object based on the detected reflected signal.

2. The system of claim 1, wherein the radar station comprises a Radar Signal and Data Processor Unit (RSDPU) which is configured to:receive In-phase / Quadrature-phase T / Rx (I / Q) symbols data from the cellular base station that is operably coupled to the receiving antenna;On site process the received T / Rx I / Q data symbols; and provide a detection and tracking signal based on the reflected signal from the flying object, orwherein the Radar Signal and Data Processor is implemented and the processing is performed by an external High Speed GPU data center Computer(HPC which uses the T / Rx IQ memory Dwell buffer transferred to the data center.

3. The system of any of claims 1 -2, wherein the cellular base station is configured to function as a STARING / HOLOGRAPHIC Radar operating concurrently and simultaneously with very low or without interfering with the designated operation of the base station in the cellular network for communication with cellular devices.

4. The system of any of claims 1-3, wherein the radar station comprises:a cellular modem with an antenna) configured to synchronize the radar station in frequency and time based on the cellular data of the base station.

5. The system of any of claims 1-4, wherein the radar station is configured to transmit a stream of pulses in a constant predetermined sequence, with the transmission time limited to no more than 200 milliseconds, which is a DWELL time.

6. The system of any of claims 1-5, wherein the transmitting antenna comprises a Hom antenna.

7. The system of any of claims 1-6, wherein the transmit antenna comprises a linear phased array antenna, or wherein the radar RF signal transmission is done by using the phased array antenna or a section of the phased array antenna of the cellular Base Station and wherein the transmission of the radar RF signal is done during uplink or GAP time.

8. The system of any of claims 1-7, wherein a time of Tx pulse duration is determined according to the cellular transmission mode selected from:A GAP TDD mode, a Time Division Duplex (TDD) mode, a Cooperative Time Division Duplex (TDD) mode, a Cyclic Prefix (CP) TDD mode, aFrequency Division Duplex (FDD) mode, a Cooperative Frequency Division Duplex (FDD), and a CP FDD mode.

9. The system of any of claims 2-8, wherein the receiving antenna comprises a phased array antenna and T / Rx I / Q symbol data from one or more transmission and reception elements (Tx / Rx) of the phase array antenna are received and collected via an optical link, wherein the optical link is operably connects the DU and a central unit (CU), and the DU is to transfer the T / Rx I / Q symbols from the phased array antenna to the CU which is configured to transfer the T / Rx I / Q data symbols and the synchronization data to the radar station.

10. The system of any of claims 2-9, wherein the RSDPU computer is configured to perform a Digital Beam Forming (DBF) by using the T / Rx I / Q symbol data to generate multiple narrow beams, whereinthe generated beams have similar angular gain patterns and overlap with neighboring beams, in both azimuth and elevation, used to provide sub-beam angular accuracy of about 1 or 2 degrees, andthe sub-beam (intra-beam) angular accuracy is achieved by combining signal in the beam where target was detected with signals from the flying object in neighboring beams, in azimuth and elevation.

11. The system of any of claims 1-10, wherein the flying object comprises at least one of an Unmanned Aerial Vehicle (UAV), a manned aerial vehicle, an airplane, a helicopter, and a flying object.

12. The system of any of claims 1-11, wherein the system comprises:a Central Data Processing Radar Surveillance Computer (CDPSC); at least two cellular base stations configured to send detected flying object data to the CDPSC, which is configured to:determine the location and a velocity vector of the flying object;merge the data of the flying object received from at least two neighboring base stations to determine and identify that the flying object data match the flying object data detected by the at least two cellular neighboring base stations;provide a first aerial image of a geographical location of the flying object received from the at least two cellular base stations, provide a second aerial image of at least one flying object with a route of the flying object on the first aerial image;display on a software application configured to display at least one detected flying object on a screen, send at least in part the geographical location of the detected flying object, velocity, direction, altitude, radar cross section, ,SNR, and any other parameters of the flying object to an Aerial Traffic Control Center (ATC), andgather the geographical location and other parameters of the detected flying object from the two or more base stations, convert at least in part the parameters, integrate the converted parameters, and create a map that illustrates the trajectory of the flying object, which visualizes the flight path of the flying object, using Track While Scan (TWS) algorithms for updating multiple targets tracks between Dwells.

13. The system of claim 12, wherein the system further comprisesa camera which is directed by cueing radar data toward the detected flying object and configured to:perform flying object identification, classification, and optical tracking of images and video of the detected flying object, and submit the information to the CDPSC for flying object classification, wherein the CDPSC is configured to send the flying object video and data to the ATC via a data link that comprises a data link.

14. The system of claim 13, wherein the information related to the flying object is shared and transferred between two or more base stations and the CDPSC via a data link, wherein the data link comprises at least one of a cellular data link, an internet network, and a link to a data cloud.

15. The system of claim 13, wherein the geographical location of the flying object, which is derived from the Base Station (BS) radar measurement, is sent to at least one other base station for directing the camera towards a detected flying object to generate an image and a video of a different view of the detected flying object for classification of the flying object.

16. The system of claim 13, wherein the RSDPU is configured to calibrate the angular interpolation parameters of an Angle of Arrival (AoA) according to the accurate AoA derived from the captured video of the flying object by the camera of the base station.

17. The system of claim 13, wherein the identification and classification of the flying object is done by using Artificial Intelligence (Al).

18. The system of any of claims claim 2-17, wherein the base station is configured to provide a power supply to the RU, the DU, the transmitter, and the radar station.

19. The system of any of claims 12-18, wherein at least one friendly flying object is configured to share and report a geographical location, an identity, and flight information with the CDPSC, which is configured to:integrate and merge parameters of friendly flying objects;represent the identified friendly flying object and an unidentified flying object in an aerial map by illustrating a geographical location, a route, a trajectory of the identified friendly flying object, and the unidentified flying object, or using the RCS of the known friendly target used for calibrating the RCS of other detected targets b.

20. The system of claim 16, wherein the high resolution on site camera is directed toward a target by using cueing radar data in order to calculate higher accuracyof the target AoA and configured to provide a geographical location of the flying object based on the AoA and a range of the flying object, wherein a detected geographical location of the flying object is distributed to at least one other base station.

21. The system of any of claims 1-20, wherein the transmitting antenna comprises:one or more linear phased array antennas comprise one or more antenna elements, wherein the one or more linear phased array antennas are mounted adjacently or above each other and use different elevation shifting of a beam center to cover together a required elevation sector, wherein an element of the linear phased array antenna has a predetermined polarization, andthe beam of the linear phased array antenna near the horizon uses optimized amplitude tapering to produce very low side lobes in the horizon direction, and the antenna gain is pre-defined above the horizon22. The system of any of claims 2-21, wherein the radar station comprises an application configured to:resolve the Doppler ambiguity in the GAP TDD mode caused by a low Pulse Repetition Frequency (PRF) in this mode by processing even and odd Tx symbols separately;calculate the phase difference between the signals detected in the even and odd sequences; andresolve a flying object Doppler ambiguity based on the calculated phase difference.

23. A method for detecting and tracking a flying object operated by a radar station comprising:synchronizing the radar station with the cellular communication standard protocol of a cellular base station, which is in communication with the radar station;transmitting by a transmission antenna of the radar station radio frequency (RF) signals on a selected frequency bandwidth of an uplink during a time window when the cellular base station is in Uplink or not transmitting to detect a flying object;receiving RF signals in the cellular bandwidth containing radar signals and standard cellular signals from the antenna of the base station;processing data received by the receiving antenna of the base station to detect a reflected signal returned from the flying object; anddetecting and tracking the flying object based on the detected reflected signal.

24. The method of claim 23, further comprising:transmitting in a constant, predetermined sequence a stream of radar pulses, wherein the transmission of the stream of pulses is time-limited to no more than 200 milliseconds, which is a DWELL time.

25. The method of any one of claims 23 or 24, further comprising:determining the Tx pulse duration according to the cellular transmission mode selected from:A GAP TDD mode, a Time Division Duplex (TDD) mode, a Cooperative Time Division Duplex (TDD) mode, a Cyclic Prefix (CP) TDD mode, a Frequency Division Duplex (FDD) mode, a Cooperative Frequency Division Duplex (FDD), and a CP FDD mode.

26. The method of any one of claims 23-25, further comprising:performing a Digital Beam Forming (DBF) by using the T / Rx I / Q symbol data to generate multiple narrow beams, whereinthe generated beams have similar angular gain patterns and an angular overlap with neighboring beams, in azimuth and elevation, and are used to provide sub-beam angular accuracy of about 1 or 2 degrees, andcombining the flying object signal in the beam with signals of the flying object in neighboring beams, in azimuth and elevation, to achieve the sub-beam angular accuracy.

27. The method of any one of claims 23-26, wherein the radar station comprises a Radar Signal and Data Processor Unit (RSDPU), and the method performed by the RSDPU comprises:receiving from a cellular Radio Unit (RU) and a Distribution Unit (DU) that are operably coupled to the receiving antenna In-phase / Quadrature-phase T / Rx(I / Q) data symbols;processing the received T / Rx I / Q data symbols; andproviding a detection and tracking signal based on the reflected signal from the flying object.

28. The method of any one of claims 23-27 comprises at least two cellular neighboring base stations configured to send a detected flying object data to a Central Data Processing Radar Surveillance Computer (CDPSC) a method employed by the CDPSC comprises:determining the location and a velocity vector of the flying object; merging the flying object data that were received from at the least two neighboring base stations to determine and identify the flying object data to be the same as the flying object data that the base station detected;providing a first aerial picture of a geographical location of the flying object that was received from the base station,providing a second aerial picture of at least one flying object with a route of the flying object on the first aerial picture;displaying using a software application that is configured to display at least one detected flying object on a display, send at least in part the geographical location of the detected flying object, a velocity, a direction, an altitude, a radararea size, and any other parameters of the flying object to an Aerial Traffic Control Center (ATC); andreceiving and collecting the geographical location and the other parameters of the detected flying object from the two or more neighboring base stations, converting at least part of the parameters, integrating, and converting into data for a map representation to illustrate the trajectory of the flying object that visualizes the flight path of the flying object.

29. The method of claim 28, wherein the method employed by the CDPSC comprises:classifying the flying object based on flying object identification, classification, and optical tracking of images and video of the detected flying object provided from a camera; andsending the flying object video and data to the ATC via a data link that comprises a data link.

Images