Abstract: Methods and apparatus for an ADS-B system having a single link for communication and/or ADS-B/Mode-S coordination. With this arrangement, the system communication is efficiently used.

Abstract: A method for validating positional data in vehicle surveillance applications wherein vehicles transmit positional data indicating their own position to surrounding vehicles using a data link over which a transmission is initiated at a given transmission point in time that is known by all users of the data link. A signal transmitted from a radio source over the data link is received at a receiving unit. The signal carries positional data indicating an alleged position of a vehicle. The distance between the receiving unit and the radio source is estimated based on the time of flight and the propagation velocity of the received signal. The time of flight is determined based on the time elapsed from the transmission point in time of the signal to the time of reception of at least a first part of the signal. A deviation value is determined.

Abstract: Systems and methods for integrated air traffic control management are provided. In one embodiment, a system comprises a first processing system including a FANS application for implementing a CPDLC and AFN system; a second processing system including an ATN application for implementing a PM-CPDLC and CM system; a third processing system implementing a HMI, the HMI configured to provide access to a first set of pages driven by the FANS application and a second set of pages driven by the ATN application; and an ATC Manager accessed from the HMI, the HMI configured to provide access to a third set of pages driven by the ATC manager, wherein the third set of pages selectively directs a user of the HMI to either the first set of pages or the second set of pages based on a selected ATC center.

Abstract: The processing method according to the invention is a method of processing replies from targets interrogated by a surveillance radar according to a mode S interrogation of all the targets present in the receiving lobe of the radar, whereby the different targets present in the receiving lobe of the radar are interrogated at least once, the set of the mode S reply signals received for this lobe are collected after each interrogation, a reply detection processing operation is performed for each target and errors are detected and, if necessary, corrected then the corresponding blips are extracted, and this method is characterized in that said signal quality detection and determination processing operation consists in forming a synthetic message with the set of replies to each interrogation for each target, establishing, for each bit of the message, the value and the quality of this bit and performing the error detection and correction using this synthetic message, and the three variables ?, ? and monopulse of all

Abstract: A computer system for registering synthetic aperture radar (SAR) images includes a database for storing SAR images to be registered, and a processor for registering SAR images from the database. The registering includes selecting first and second SAR images to be registered, individually processing the selected first and second SAR images with an anisotropic diffusion algorithm, and registering the first and second SAR images after the processing. A shock filter is applied to the respective first and second processed SAR images before the registering. Elevation data is extracted based on the registered SAR images.

Abstract: The device (405) for behavior simulation of a radio navigation system, without the latter being installed on an aircraft, comprising a means (410) for determining a position of the aircraft, characterized in that it further comprises: a means (415) for automatically determining at least one radio navigation beacon of a station on the ground depending on said position of the aircraft, and for selecting a radio navigation beacon of an automatically determined station on the ground, a means (420) for calculating at least one physical quantity value linked to the relative position of the aircraft relative to the selected beacon and a means (425) for presenting, on a display means of the aircraft cockpit, each calculated physical quantity value and the identifier of the selected beacon.

Abstract: An aircraft system includes a transponder and a processor. The processor is configured to determine if the aircraft is positioned in a predetermined restricted flying zone. If the aircraft is positioned in a predetermined restricted flying zone, the processor determines if the transponder is functioning in a transmit mode. If the transponder is not functioning in a transmit mode, the processor sets the transponder to function in a transmit mode.

Abstract: Embodiments of an apparatus and method for defending a physical zone from airborne and ground-based threats are disclosed. In the various embodiments, an apparatus includes a detection component configured to detect and track a ground-based or airborne threat proximate to the physical zone, an integration component to receive data from the detection component and process the data to determine a threat assessment. A defensive component receives the determined threat assessment and disables the ground-based and airborne threat based upon the determined threat assessment. A method includes detecting an object proximate to the physical zone to be protected, identifying the object as a hostile threat, determining at least one of a path and a point-of-origin for the object, and actuating a defensive system in response to the hostile threat.

Abstract: Methods and apparatus for preventing spoofing of targets, such as aircraft, in an air traffic control system. In one embodiment, first and second antennas at respective ground stations can be used to receive a signal transmitted by an aircraft from which a phase signal can be generated. A position of the aircraft generate can be generated from peaks and troughs in the phase signal due to movement of the aircraft. The determined position can be compared to a position reported by the aircraft to identify spoofing of the target.

Abstract: An air traffic control automatic dependent, WAAS/GPS based, surveillance system (ADS), for operation in the TRACON airspace. The system provides encryption protection against unauthorized reading of ADS messages and unauthorized position tracking of aircraft using multilateration techniques. Each aircraft has its own encryption and long PN codes per TRACON and transmit power is controlled to protect against unauthorized ranging on the ADS-S aircraft transmission. The encryption and PN codes can be changed dynamically. Several options which account for available bandwidth, burst data rates, frequency spectrum allocations, relative cost to implement, complexity of operation, degree of protection against unauthorized users, system capacity, bits per aircraft reply message and mutual interference avoidance techniques between ADS-S, ADS-B Enroute and Mode S/ATCRBS TRACON are disclosed. ADS messages are only transmitted as replies to ATC ground terminal interrogations (no squittering).

Abstract: A radar unit on board an aircraft scans a scan area of surrounding space relative to a runway to detect any nearby aircraft and a unit presents to a pilot an indication of such detection of the presence of at least one nearby aircraft. The technique involves determining: a heading of the aircraft, positions of thresholds of the runway, an orientation of the runway, a maximum relative bearing, a minimum relative bearing, a maximum elevation, a minimum elevation, a slant range for scanning the scan area from the heading, thresholds and orientation, predetermined vertical and horizontal angles of an approach center line of the runway, a predetermined length of edges of the scan area, and the scan commands enabling the radar to scan said scan area using the maximum relative bearing, the minimum relative bearing, the maximum elevation, the minimum elevation and the slant range.

Abstract: Provided is a secondary surveillance radar with an improved capability of eliminating an unnecessary Mode A/C target report, which includes a transmission unit transmitting interrogations, a reception unit receiving replies, from a transponder, corresponding respectively to the interrogations, and a signal processing unit generating a Mode S target report and a Mode A/C target report from the replies. The radar also includes a combiner generating a Mode S track and a Mode A/C track respectively from the Mode S and the Mode A/C reports, and then judging whether the Mode S report and the Mode A/C report are of the same target on the basis of the Mode S and the Mode A/C tracks. When the Mode S and the Mode A/C reports are of the same target, the combiner rejects the Mode A/C report.

Abstract: A transmitter 122 transmits interrogations to aircraft airborne in a coverage, a receiver 123 receives signals transmitted from aircraft airborne in the coverage, reply analyzers 132b and 133b analyze a reply responding to an interrogation transmitted from the transmitter, as the reply is detected from signals received by the receiver, and a squitter analyzer 132d analyzes an extended squitter, as the extended squitter is detected from the signals received by the receiver.

Abstract: Navigation of an aircraft is facilitated through the displaying on a map of an over flown region, and of the limits of zones within range of the aircraft in an emergency situation. The points of the zones within range of the aircraft are tagged on the basis of: an estimate of the vertical margins to reach these points, taking into account non-maneuverability zones neighboring the aircraft to be circumvented; a vertical flight profile to be complied with; and a safety height margin.

Abstract: A method according to the present invention includes transmitting a Mode S interrogation and receiving a response from an aircraft that has received the Mode S interrogation. A range to the aircraft is determined based on a time period between transmitting the Mode S interrogation and receiving the response. The method further includes receiving information from one or more data sources and determining at least one of a bearing to the aircraft and a position of the aircraft using the determined range and the information from the one or more data sources. Information can be received from any number (or type) of data sources, such as ADS-B-equipped aircraft.

Abstract: In accordance with one or more embodiments of the present disclosure, systems and methods disclosed herein provide for tracking of objects, aircraft, vehicles, and ground equipment in a tracking area, such as an airspace and/or an airport terminal area. One embodiment of a tracking system of the present disclosure comprises a signal monitoring component adapted to communicate with an object, such as an aircraft, when the object enters the tracking area. The signal monitoring component is adapted to transmit a monopulse beacon query signal to the object and receive a monopulse beacon response signal from the object. The tracking system further comprises an interface component adapted to process the received monopulse beacon response signal from the object, initialize a beacon transponder on the object, and assign a network address to the object.

Abstract: An aircraft system includes a transponder and a processor. The processor is configured to determine if the aircraft is positioned in a predetermined restricted flying zone. If the aircraft is positioned in a predetermined restricted flying zone, the processor determines if the transponder is functioning in a transmit mode. If the transponder is not functioning in a transmit mode, the processor sets the transponder to function in a transmit mode.

Abstract: A transmitter (13) operates in an immediate scan after an initial acquisition or detection of an altered aircraft ID by a changed flight status, to transmit to an aircraft a sequence of interrogation signals requesting an aircraft ID transmission, a verifier (17) operates upon acquisition of a reply signal including an aircraft ID transmitted from a transponder on the aircraft, to store in a memory (17a) a mode S address assigned to the aircraft and the aircraft ID in an associating manner, and upon an occurrence of a storage of aircraft IDs associated with the mode S address in the memory (17a), to determine whether or not the aircraft ID is correct, depending on whether or not the aircraft IDs have a match therein, and a report generator (18) operates upon a determination for the aircraft ID to be correct, to prepare a target report using the aircraft ID.

Abstract: A method and apparatus for determining a value of each bit in a secondary radar response pulse train sampled at a bit rate greater than one sample per bit is provided. The received signal is sampled repeatedly over a bit period. A scale factor for a weighting function is defined based on the amplitude levels detected from the response preamble. The weighting function has a maximum positive value at the expected bit amplitude for the first half of the bit period and decays to zero at higher amplitudes so that the effect of very large samples will be negligible. For lower amplitudes, the weighting decays to zero at the threshold level and becomes increasingly negative until zero amplitude. In the second half of the bit period the sign of the weighting function is swapped compared to the first half. The amplitude samples taken during the bit period are then each applied to the weighting function and the sum of the weighting function for the samples taken over the bit period is calculated.

Abstract: An aircraft control unit has modules for interfacing with various systems of an aircraft to integrate control of the systems. The modules include a communication module configured to be coupled to a communication system of the aircraft and a surveillance module configured to be coupled to a surveillance system of the aircraft. The aircraft control unit also includes a display screen for displaying information and a user interface usable to interact with the modules. Each of the modules is configured to display information on the display screen and to receive user input from the user interface.

Abstract: Embodiments of the present invention disclose systems and methods for providing an avionics overlay data link. Through embodiments of the present invention, existing ATC (or other) modulated signals using existing frequencies (or other frequencies) may be utilized to transmit (e.g., from an aircraft transponder) additional information in a manner that does not render the transmitted signal unrecognizable by legacy ATC equipment. In various embodiments, legacy equipment may demodulate and decode information that was encoded in the transmitted signal in accordance with preexisting standard modulation formats, and updated equipment can also extract the additional information that was overlaid on transmitted signals.

Abstract: The invention relates to a method for pre-detecting responses in a secondary radar. It applies in particular to the detection of mode S responses. An aim of the invention is to process the signals received before decoding the responses so as to allow the detection of mixed responses, and avoid the detection of ghost responses. For this purpose, the invention has in particular as subject a method for pre-detecting responses in a secondary radar, the responses to be pre-detected comprising a message coded by a modulated signal, characterized in that the presence of a signal exhibiting modulation characteristics in accordance with those of a message of a response to be pre-detected is identified; the duration of the signal identified is measured; this duration is compared with a minimum duration, this minimum duration being determined on the basis of the duration of the messages of the responses to be pre-detected.

Abstract: A transponder unit of a DME ground apparatus receives an interrogation signal and converts the same to an IF signal. The unit performs analog-to-digital conversion on the IF signal, generating a digital interrogation signal. The unit calculates two detected outputs whose frequencies are ±900 kHz deviated with respect to the center frequency of the digital interrogation signal. Then, the transponder unit compares the two detected outputs and the digital interrogation signal in terms of magnitude, thereby to determine whether a response signal should be transmitted.

Abstract: A secondary surveillance radar system comprising a including a ground system which observes an observation area where an aircraft equipped with a mode S transponder and an aircraft equipped with an ATCRBS transponder possibly coexist, wherein the ground system comprises includes a transmit processor which transmits to the observation area an all-call interrogation signal specific for mode S including an identification code of the ground system, a receive processor which receives a reply signal to the interrogation signal transmitted by the transmit processor, and a recognition processor which recognizes the reply signal as a processing target when identification information included in the reply signal received by the receive processor coincides with the identification code of the ground system, and wherein the recognition processor recognizes the reply signal as the processing target also when the identification information included in the reply signal received by the receive processor coincides with null in

Abstract: The processing method according to the invention is a method of processing replies from targets interrogated by a surveillance radar according to a mode S interrogation of all the targets present in the receiving lobe of the radar, whereby the different targets present in the receiving lobe of the radar are interrogated at least once, the set of the mode S reply signals received for this lobe are collected after each interrogation, a reply detection processing operation is performed for each target and errors are detected and, if necessary, corrected then the corresponding blips are extracted, and this method is characterized in that said signal quality detection and determination processing operation consists in forming a synthetic message with the set of replies to each interrogation for each target, establishing, for each bit of the message, the value and the quality of this bit and performing the error detection and correction using this synthetic message, and the three variables ?, ? and monopulse of all

Abstract: Methods and apparatus for assigning a pseudo address to an aircraft not equipped with an ADS-B transponder and maintaining the assigned pseudo address over a number of regions each supported by different TIS-B systems. In an exemplary embodiment, each TIS-B system is assigned a range of addresses particular to the region in which the TIS-B system is located.

Abstract: Embodiments of the present invention disclose systems and methods for providing an ATC Overlay data link. Through embodiments of the present invention, existing ATC (or other) modulated signals using existing standard frequencies may be utilized to transmit (e.g., from an aircraft transponder) additional information in a manner that does not render the transmitted signal unrecognizable by legacy ATC equipment. Legacy equipment will be able to demodulate and decode information that was encoded in the transmitted signal in accordance with preexisting standard modulation formats, and updated equipment can also extract the additional information that was overlaid on transmitted signals.

Abstract: Methods and apparatus for an ADS-B system having a single link for communication and/or ADS-B/Mode-S coordination. With this arrangement, the system communication is efficiently used.

Abstract: In the described system the multilateration process to be applied to determine an aircraft's position is chosen on the basis of the available returns, receiver geometry and the height of the aircraft.

Abstract: The invention applies to secondary radars. It makes it possible to carry out filtering when seeking to detect SSR responses, these SSR responses being overlapped by a mode S response. According to the invention, the pulses of the mode S response are filtered without filtering the pulses of the SSR responses which are of a higher level than the mode S response.

Abstract: Methods and apparatus to detect and measure energy transmission or azimuth angle information from a radar system at one or more known or measured azimuth angles, determine, for each azimuth angle, the time corresponding to the center of the beam of the energy transmission, receive universal time information, tag the time measurement for each azimuth angle with the universal time information to provide a report, transmit the report to a radar automation system, and determine the radar measurement time for each target report at any azimuth angle from that radar.

Abstract: Disclosed is a Mode S radar which specifies an aircraft by transmitting interrogations to an aircraft A equipped with a Mode S transponder, and by then receiving and decoding replies corresponding to these interrogations. In the Mode S radar, detection reports on the aircraft A are generated in a manner that: for a Mode A code necessary for generating detection reports, when identicalness between the Mode A codes obtained in a plurality of scans after the initial acquisition of the aircraft A has been found to exist, the Mode A code thus found identical is adopted without carrying out a Mode A code interrogation (UF=5) thereafter. Accordingly, the Mode S secondary surveillance capable of generating more highly reliable detection reports is achieved.

Abstract: There are presented various approaches to monitor performance of RF systems and circuitry such as those used in aircraft transponders. Such monitoring may be designed to verify operational performance of transponders as set forth by FAA regulations, or may be used to periodically or continually monitor integrity of transponder performance. Data may be collected by such periodic or continual monitoring, and may be analyzed to identify potentially troublesome trends in transponder performance, allowing early intervention or repair, if warranted.

Abstract: The device (1) comprises a radar (2) which is able to detect any nearby aircraft and means (7) for presenting to a pilot an indication indicating, as appropriate, such a detection.

Abstract: A system able to locate and identify aircraft and vehicles based on the reception and processing, with novel means and methods, of signals emitted by the transponder of the secondary surveillance radar, shortly SSR. The system has a number of fixed stations distributed in the area of interest, e.g. in the airport area; any signal (the well known SSR reply/squitter) transmitted by the on-board transponder is received by four or more stations and the measurement of three or more differences of times of arrival (TOA) permits the reconstruction of the position of the transponder in spite of the fact that the transmission time is unknown. Suitable algorithms based on optimal estimation enhance both the accuracy of TOA measurements and the accuracy of the reconstructed position. The effects of possible overlapping of signal in time are avoided or mitigated by multiple source separation techniques based on least squares algebraic processing.

Abstract: Cooperating mobiles (ground vehicles, aircraft) are located and identified by Multilateration and Automatic Dependent Surveillance-Broadcast (ADS-B) techniques using the frequency band and the format of the Secondary Surveillance Radar (SSR) signals in high traffic situations. Standard messages, transmitted by the mobile on the downlink channel, i.e. to a set of fixed receiving stations, and including the identification code, permit the location of the mobile by multiple time measurements (Multilateration) from a subset of the set of fixed receiving stations; when the message contains the position (GPS and, later, Galileo datum) the mobile may be located with the ADS-B when in view even of a few stations or of a single station. In order to overcome the problem that arises with high traffic, i.e. the superimposition of signals, called garbling.

Abstract: A system and method for target classification for an aircraft surveillance radar is provided. In one implementation, the track classifier provides tracks with an updated probability value based on its likelihood to conform to aircraft and non-aircraft target behavior. The track classifier identifies false tracks that may arise from weather and biological targets, and can detect aircrafts lacking Secondary Surveillance Radar (SSR) data. Various features and combinations of features are evaluated using a proposed clustering performance index (CPI) and used to discriminate between aircrafts and false tracks.

Abstract: A precision radar registration (PR2) system and method that employs highly accurate geo-referenced positional data as a basis for correcting registration bias present in radar data. In one embodiment, the PR2 method includes sample collection and bias computation function processes. The sample collection process includes ADS-B sample collection, radar sample collection, and time alignment sub-processes. The bias computation function process includes bias computation, quality monitoring and non-linear effects monitoring sub-processes. The bias computation sub-process results in a bias correction solution including range bias b?, azimuth bias b?, and time bias bT parameters. The quality monitoring sub-process results in an estimate of solution quality. The non-linear effects monitoring sub-process results in detection of the presence of non-linear bias, if any, in the bias correction solution.

Abstract: Disclosed is a Mode S radar which specifies an aircraft by transmitting interrogations to an aircraft A equipped with a Mode S transponder, and by then receiving and decoding replies corresponding to these interrogations. In the Mode S radar, detection reports on the aircraft A are generated in a manner that: for a Mode A code necessary for generating detection reports, when identicalness between the Mode A codes obtained in a plurality of scans after the initial acquisition of the aircraft A has been found to exist, the Mode A code thus found identical is adopted without carrying out a Mode A code interrogation (UF=5) thereafter. Accordingly, the Mode S secondary surveillance capable of generating more highly reliable detection reports is achieved.

Abstract: A transmitter (13) operates in an immediate scan after an initial acquisition or detection of an altered aircraft ID by a changed flight status, to transmit to an aircraft a sequence of interrogation signals requesting an aircraft ID transmission, a verifier (17) operates upon acquisition of a reply signal including an aircraft ID transmitted from a transponder on the aircraft, to store in a memory (17a) a mode S address assigned to the aircraft and the aircraft ID in an associating manner, and upon an occurrence of a storage of aircraft IDs associated with the mode S address in the memory (17a), to determine whether or not the aircraft ID is correct, depending on whether or not the aircraft IDs have a match therein, and a report generator (18) operates upon a determination for the aircraft ID to be correct, to prepare a target report using the aircraft ID.

Abstract: Disclosed is a Mode S radar which specifies an aircraft by transmitting interrogations to an aircraft A equipped with a Mode S transponder, and by then receiving and decoding replies corresponding to these interrogations. In the Mode S radar, detection reports on the aircraft A are generated in a manner that: for a Mode A code necessary for generating detection reports, when identicalness between the Mode A codes obtained in a plurality of scans after the initial acquisition of the aircraft A has been found to exist, the Mode A code thus found identical is adopted without carrying out a Mode A code interrogation (UF=5) thereafter. Accordingly, the Mode S secondary surveillance capable of generating more highly reliable detection reports is achieved.

Abstract: Systems and methods for communication using a plurality of data link standards through a common operator interface are disclosed. In one embodiment, the system includes components configured to select and establish communication with an air traffic control center using one of a plurality of data link standards. The system further includes components configured to format at least one downlink page to only allow appropriate data inputs based on one or more functionalities of the data link standard, and encode one or more entered data inputs based on the selected data link standard and transmit the inputs to the air traffic control center. In a particular embodiment, the system further includes a components configured to receive and display each of the decoded uplink data transmission in a text message on a corresponding uplink display page according to one or more message text conventions of the selected data link standard.

Abstract: An airport surface target detection, classification and tracking system using a network of multilateration (SSR) sensors and W-band radar sensors is used to provide automatic location and tracking information about ground moving aircraft or targets. The information from the distributed sensors are coordinated to provide accurate location and tracking information for coordination of surface traffic and navigation within an airport.

Abstract: There are provided a differential processing unit which performs differential processing for a Mode S transponder transmission signal, an auto correlation arithmetic operation unit which performs an arithmetic operation of a degree of auto correlation between an increasing change rate and decreasing change rate of a power level in the signal which has been subjected to the differential processing, a pulse regeneration unit which regenerates a pulse based on the degree of auto correlation, which has been obtained by the auto correlation arithmetic operation processing, a pulse phase locked loop unit which performs gate processing and phase locked processing for the regenerated pulse, and a pulse decoding unit which decodes the Mode S transponder transmission signal based on the pulse which has been subjected to the gate processing and the phase locked processing.

Abstract: An air traffic control automatic dependent, WAAS/GPS based, surveillance system (ADS), for operation in the TRACON airspace. The system provides encryption protection against unauthorized reading of ADS messages and unauthorized position tracking of aircraft using multilateration techniques. Each aircraft has its own encryption and long PN codes per TRACON and transmit power is controlled to protect against unauthorized ranging on the ADS-S aircraft transmission. The encryption and PN codes can be changed dynamically. Several options which account for available bandwidth, burst data rates, frequency spectrum allocations, relative cost to implement, complexity of operation, degree of protection against unauthorized users, system capacity, bits per aircraft reply message and mutual interference avoidance techniques between ADS-S, ADS-B Enroute and Mode S/ATCRBS TRACON are disclosed. ADS messages are only transmitted as replies to ATC ground terminal interrogations (no squittering).

Abstract: A method to efficiently implement a reconfigurable electronic radio system (400) including resource assets (402-408, 410-416, 418, 420-426, 428) and a processor (428). The processor (428) generates RF control and switching control signals during each mission segment of an aircraft to create radio function threads through the resource assets (402-408, 410-416, 418, 420-426, 428) to realize the radio functions for that mission segment. The processor (428) may also be coupled to a master processor (440) that sends the processor (428) a radio function set selection signal. The radio function set selection signal identifies the radio function set that the processor (428) will implement through the resource assets (402-408, 410-416, 418, 420-426, 428). The processor (428) performs all signal, data, message, cryptographic and control processing required for the radio function threads being implemented by the resource assets.

Abstract: A method and system are provided for measuring and monitoring performance metrics of a non-ADS-B tracking system and generating performance metrics for the non-ADS-B tracking system in terms of ADS-B equivalent performance metrics. An aircraft transmits various transponder-based or other signals which are received at multiple ground stations, some of which may be ADS-B stations or both ADS-B and multilateration stations. ADS-B signals may contain performance metrics which are passed on from ADS-B station to an ADS-B processor, which outputs aircraft-derived metrics. ADS-B signals and all other transponder signals are also received at all ground stations, time-stamped, and sent to a multilateration processor, which generates multilateration metrics. Therefore two streams of information are passed onto ATC system processor containing the ADS-B aircraft-derived metrics and multilateration-derived metrics.

Abstract: A system able to locate and identify aircraft and vehicles based on the reception and processing, with novel means and methods, of signals emitted by the transponder of the secondary surveillance radar, shortly SSR. The system has a number of fixed stations distributed in the area of interest, e.g. in the airport area; any signal (the well known SSR reply/squitter) transmitted by the on-board transponder is received by four or more stations and the measurement of three or more differences of times of arrival (TOA) permits the reconstruction of the position of the transponder in spite of the fact that the transmission time is unknown. Suitable algorithms based on optimal estimation enhance both the accuracy of TOA measurements and the accuracy of the reconstructed position. The effects of possible overlapping of signal in time are avoided or mitigated by multiple source separation techniques based on least squares algebraic processing.

Abstract: A method and system for using a single transceiver to correlate radar position data with target identification data. Two transceivers, operating in round trip delay mode, can be used to provide two possible positions for a given target when radar coverage is lost or unavailable. Three transceivers can be used to provide actual position of a given target using round trip delay data only.

Abstract: A method and system are provided for measuring and monitoring performance metrics of a non-ADS-B tracking system and generating performance metrics for the non-ADS-B tracking system in terms of ADS-B equivalent performance metrics. An aircraft transmits various transponder-based or other signals which are received at multiple ground stations, some of which may be ADS-B stations or both ADS-B and multilateration stations. ADS-B signals may contain performance metrics which are passed on from ADS-B station to an ADS-B processor, which outputs aircraft-derived metrics. ADS-B signals and all other transponder signals are also received at all ground stations, time-stamped, and sent to a multilateration processor, which generates multilateration metrics. Therefore two streams of information are passed onto ATC system processor containing the ADS-B aircraft-derived metrics and multilateration-derived metrics.