Abstract: An autonomous airspace system for urban air mobility monitors flight separation for compliance with a safe separation distance. A reference formation airspace is established for a reference air taxi based on minimum longitudinal, lateral and vertical parameters. When penetration of the reference formation airspace is detected, a penetration airspace is established based on a deformation of the reference formation airspace caused by the penetrating air taxis. A centroid of the penetration airspace is determined and a target separation to the centroid is supplied to the air taxi to reestablish safe separation. The extent of separation is also safely contained by the presence of virtual air taxis whose positions on the periphery of the penetrated airspace serve to limit potential penetration of surrounding air taxi air spaces.

Abstract: A method includes: receiving a ranging signal from the transmitter comprising a set of multiplexed sub-signals, each multiplexed sub-signal characterized by a frequency in a set of frequencies; calculating a time-based time-of-arrival estimate based on the series of time-domain samples of the ranging signal; calculating a time-based uncertainty of the time-based time-of-arrival; for each sub-signal pair in a subset of multiplexed sub-signals of the set of multiplexed sub-signals, extracting a phase difference of the sub-signal pair; calculating a phase-based time-of-arrival estimate based on the phase difference of each sub-signal pair in the subset of multiplexed sub-signals; calculating a phase-based uncertainty of the phase-based time-of-arrival estimate; and calculating a hybrid time-of-arrival estimate as a weighted combination of the time-based time-of-arrival estimate, the phase-based time-of-arrival estimate, based on the time-based uncertainty and the phase-based uncertainty.

Abstract: Systems and methods for push-based dynamic bandwidth allocation deliver addressable, advertising content in a digital network. Bandwidth is allocated on a push basis in response to receiving a trigger from a content distribution stream. The trigger contains data indicating an addressable break. A portion of bandwidth is then allocated to an addressable content stream based on the data of the trigger. The addressable content stream is then streamed to a receiver during the addressable break and the receiver is tuned from the broadcast stream to the addressable content stream for the duration of the addressable break. The additional bandwidth is de-allocated at the end of the addressable break.

Abstract: An autonomous airspace separation system monitors flight separation for compliance with a separation standard. A reference formation airspace is established based on minimum longitudinal, lateral and vertical parameters. When penetration of the reference formation airspace is detected, a penetration airspace is established based on a deformation of the reference formation airspace caused by the penetrating aircraft. A centroid of the penetration airspace is determine and a target separation to the centroid is supplied to the aircraft to reestablish safe separation.

Abstract: A transceiver assembly is configured to detect an object. The transceiver assembly includes a first transmit antenna array configured to transmit a first signal at a first frequency, a second transmit antenna array configured to transmit a second signal at a second frequency that differs from the first frequency, and a receive antenna array configured to receive a third signal at a third frequency that is a difference between the first frequency and the second frequency. The transceiver assembly detects the object in response to reception of the third signal by the receive antenna array.

Abstract: A system for aircraft communications comprises an avionics processing unit onboard an aircraft, and a computing platform onboard the aircraft and in operative communication with the avionics processing unit. The computing platform hosts at least one application and one or more aircraft navigational charts with Air Traffic Control (ATC) center identifying information. An aircraft data network is also in operative communication with the computing platform. The avionics processing unit is operative to receive an ATC center facility designator input by a user or from another onboard avionics system, and to transmit the ATC center facility designator to the computing platform. The application is operative to query the aircraft navigational charts based on the ATC center facility designator to obtain corresponding ATC center identifying information, and to send the corresponding ATC center identifying information to the avionics processing unit.

Abstract: Methods and apparatus relating to techniques for Electromagnetic Interference (EMI) mitigation on high-speed lanes using false stall are described. In one embodiment, protocol logic determines whether to perform a false stall operation on a lane in response to a determination that no data is to be sent over the lane and that data is being transmitted over the lane. The false stall operation includes sending one or more training symbols (e.g., immediately) after an End Of Burst (EOB) signal over the lane, instead of allowing the lane to stall. Other embodiments are also disclosed.

Abstract: Systems and methods for a non-integrated CPDLC solution are provided. In one embodiment, the system includes: a first and second computing system for respectively executing a first and second CPDLC application; a Human Machine Interface coupled to the first and second computing systems, the Human Machine Interface providing access to display screens generated by both the first and second CPDLC applications; and a data authority function that determines a data authority application from the first and second CPDLC applications based on which of the first and second CPDLC applications has a current data authority (CDA) session. The data authority function prevents the first CPDLC application from establishing a concurrent current data authority session when the second CPDLC application is the data authority application. The data authority function prevents the second CPDLC application from establishing a concurrent current data authority session when the first CPDLC application is the data authority application.

Abstract: In one embodiment, a method for implementing a non-integrated CPDLC solution is provided. The method includes monitoring a datalink router for messages from a first CPDLC application in a first one or more execution partitions, wherein the first one or more execution partitions are configured to implement a first CPDLC application and wherein messages from the first CPDLC application and a second CPDLC application in a second one or more execution partitions use the datalink router to interface with one or more radio transceivers. The method also includes when the second CPDLC application has an active current data authority (CDA) air traffic control (ATC) connection, inhibiting communication between the first CPDLC application and an ATC ground station by discarding downlink messages of the first CPDLC application from the datalink router.

Abstract: The concepts relate to radio channel utilization. One example can channel bond a first available channel from a first radio frequency band with a second available channel from a second radio frequency band. The example can transmit a portion of a forward error correction coded data stream over the first available channel and a different portion of the forward error correction coded data stream over the second available channel.

Abstract: A method for calibrating an ESA radar to mitigate degradation of its radiation system. The radiation system includes the distribution manifold, the ESA radiating elements and the radome the ESA may be operating through. Sensing of degradation takes place both locally with a switchable matched load to identify individual ESA element characteristics and globally with target based radar return data. The data generated by this sensing of both local and global characteristics is then used to modify available ESA element complex weighting to produce a desired far-field radiation pattern.

Abstract: A method for detecting a message provided with a preamble with a number of pulses in a signal sent by an interrogator or a transponder in mode S, said method including a step for decomposition of said signal into an amplitude signal and into a complex phase signal, a step for detection of said preamble by correlating the amplitude signal with a replica signal of the expected pulses, and a phase control step executed by adding together the samples of the phase signal for the duration of the pulses of said preamble and by comparing the sum obtained with a threshold. The method may include a step for time synchronization by correlation of the complex phase signal with a reference sequence formed by one or more known bits before the decoding of the data. The method applies notably to the decoding of interrogation messages borne by low-power signals.

Abstract: Systems and methods for receiving ADS-B messages in environments where multipath propagation corrupts the messages or blocks the reception of the messages. An exemplary system combines RF signal processing and digital signal processing techniques to make it possible to receive ADS-B messages in the presence of multipath reflections from nearby structures and/or farther out structures. The system uses an array of horizontally spaced antennas. The RF signals from the antennas are combined by the receiver so as to form a set of beams with different azimuth antenna patterns to increase the probability that the multipath does not combine destructively with the line-of-sight path in at least one of the beams. This effectively removes multipath reflections where the delay of the multipath relative to the line-of-sight path is less than 100-200 nanoseconds. The system is also configured to remove multipath reflections with greater delays relative to the line-of-sight path.

Abstract: An aircraft communication system and corresponding method for establishing a datalink network between participating aircrafts, wherein each participating aircraft comprises a datalink transponder for sending and receiving standard communication messages (M) over a standard communication protocol; said datalink transponders are employed for establishing said datalink network using a standard communication protocol, and wherein said datalink transponders transmitting event driven messages (M) with a predefined structure identifying said messages (M) as test messages (TM) and at the same time comprising message data (MD) for establishing said datalink network, thus providing a datalink network established by transmission of solely messages (M) compliant with said standard communication protocol.

Abstract: A method for the real-time management and sequencing of the information interchanges between a secondary radar and a plurality of aircraft includes the interchanges between the radar and a given aircraft being performed, depending on the aircraft concerned, either in a non-selective, SSR, IFF or “All Call” interrogation mode or in a selective “Roll Call” interrogation mode. According to this method, the information interchanges according to the non-selective interrogation modes are performed during successive periods specifically allocated to these modes, whereas each transaction forming an information interchange in selective mode between the radar and a given aircraft is temporally inserted into the time slots not used in periods by the interrogation-response tasks in non-selective mode. The method applies equally to the secondary radars exclusively dedicated to civilian air traffic control and to the secondary radars dedicated to combined civilian and military aircraft control tasks.

Abstract: An ADS-B system associated with an aircraft is configured to furnish an indication whether the aircraft is within coverage of air traffic information transmitted by an air traffic control ground station. The ADS-B system receives transmissions from an air traffic control ground station that include air traffic information and a client list comprising identification addresses of aircraft included in the air traffic information. The ADS-B system determines whether the aircraft is within a range of a second aircraft and whether the second aircraft is included in the air traffic information by comparing an identification address of the second aircraft with the identification addresses in the client list. The ADS-B system furnishes an indication that the aircraft is within coverage of the air traffic information when the second aircraft is included in the air traffic information and the aircraft is within the range of the second aircraft.

Abstract: Techniques are described that allow a system, such as a portable ADS-B-enabled device, to automatically determine whether the aircraft in which the system is employed is included in air traffic information (e.g., TIS-B air traffic information) broadcast by an air traffic control (ATC) ground station. The system includes a receiver assembly to receive a first transmission from a transponder of the aircraft that includes an identification address (e.g., an ICAO address) that identifies the aircraft. The receiver assembly also receives a second transmission from the ATC ground station that includes air traffic information and a client list including identification addresses of aircraft included in the air traffic information. The identification address of the aircraft is retrieved from the first transmission and used to determine whether the aircraft is included in the air traffic information by comparing the identification address with the identification addresses in the client list.

Abstract: A system and method for exchanging information between aircraft (210). Sensors on a first aircraft (210) provide data about the first aircraft's environment, including hazards such as turbulence, icing, lightning, or birds. The system transmits the data to receiving systems in other aircraft (210), which display the data, to warn the pilots flying the other aircraft of potential hazards. The pilot of the first aircraft may supplement the information with visual observations, about birds or unmanned aerial vehicles, for example. In one embodiment, the information is transmitted from aircraft to aircraft over a data link using ADS-B. In another embodiment, a first aircraft may transmit data to a second aircraft, which may relay, or re-transmit, the data to a third aircraft.

Abstract: There is provided an avionics system that provides several avionics functions within a single LRU. In one embodiment, the system comprises a software-configurable RF assembly, one or more processor assemblies that are configured to provide multiple TAWS/TCAS/Mode S/ADS-B/ATC functions, interfaces to allow connections to aircraft electronics and data loaders, and multipurpose antennas. In one embodiment, a common processor architecture allows generic avionics processors to be configured to operate a number of TAWS/TCAS/Mode S/ADS-B/ATC functions without the need for multiple LRUs, and software-defined RF functions allow RF circuitry that interfaces to the processors to handle current and future communication needs.

Abstract: The present invention is a method for aiding pilots in resolving flight identifier (flight ID) confusion. The method includes receiving a first flight ID in a processing system. The method further includes comparing the first flight ID to a second flight ID. The method further includes providing an alert when the compared first flight ID and second flight ID are at least substantially similar. The first flight ID is associated with a first aircraft, the second flight ID is associated with a second aircraft, the first aircraft and second aircraft being located in substantially proximal airspace.

Abstract: A secondary surveillance radar with rotating antenna, configured for transmitting interrogations in S or IFF mode and processing the responses to these interrogations. The radar includes an antenna having a lobe with three channels, a Sum channel, a Difference channel and a Control channel, whose transmission means are configured for transmitting interrogation messages over the Sum and Difference channels and whose reception and processing means are configured so as to carry out, aside from conventional detections by the Sum channel, detections by the Difference channel of the responses from the aircraft having been subjected to interrogation by this same channel. The radar also includes means for Space-Time Management configured for generating interrogation messages and determining whether a given message is to be transmitted by the Sum channel, by the Difference channel or by the two channels simultaneously and controlling its transmission by the corresponding transmission channel.

Abstract: A method for validating received positional data in vehicle surveillance applications. A signal carrying a Mode S ES message including positional data indicating an alleged position of a vehicle, transmitted from a radio source is received with a radio direction finding antenna of a receiver. A bearing from the receiver to the radio source is estimated utilizing the radio direction finding antenna and received signal. A distance between the receiver and radio source based on a time of flight for a signal travelling between the receiver and radio source at known speed is estimated with a distance measurer including primary radar, laser detector and ranger, and/or secondary surveillance radar. An estimated position of the radio source is calculated based on the estimated bearing and distance. A deviation value indicating a deviation/coincidence between the alleged position is determined according to the received and estimated position of the radio source.

Abstract: An apparatus and method to generate and detect virtual targets. Position information for one or more virtual targets is calculated onboard a vehicle from real position information obtained from GPS satellites or other external or internal sources. This virtual position information is coded, mixed with a carrier frequency, amplified, and radiated to a nearby test vehicle, such as an aircraft. The amplitude of the radiated signal is adjusted such that the signal containing the virtual position information is received by the test aircraft only. The radiated signal thus adjusted is below the detection threshold of any aircraft further away. The test aircraft decodes the signal and interprets the decoded virtual position information as real aircraft in its vicinity. The coded signals may be structured to comply with the requirements of the FAA's ADS-B system. The apparatus may be mounted on the test aircraft itself, or on a nearby aircraft.

Abstract: The present invention relates to a system (300) for reducing or cancelling unwanted signals when detecting objects of interest with a detection system (200). The detection system thereby is an antenna based system using two or more receive beams as echo response to an emission signal. The system (300) for reducing or cancelling unwanted signals comprises an input means (310) adapted for obtaining from said antenna system (210) receive signals from a first receive beam and receive signals from at least one second receive beam responsive to the same emission signal. It furthermore comprises a coupling means (320) adapted for coupling the receive signals from the first receive beam to the receive signals from the at least one second receive beam, so as to obtain a detection signal for the objects of interest with suppressed unwanted signal contribution.

Abstract: An Automatic Dependent Surveillance-Broadcast (ADS-B) system, and method of harmonizing a transponder Squawk code and an ADS-B system, ensures that a Squawk code broadcast by the ADS-B system matches the transponder Squawk code. The transponder Squawk code is transmitted from a transponder positioned onboard an aircraft and the transmitted transponder Squawk code with a device positioned onboard the aircraft. A Squawk code input of an ADS-B Squawk code to be transmitted with the ADS-B system is received. The ADS-B Squawk code is compared with the received transmitter Squawk code using a comparator and the pilot is informed whether the transmitter Squawk code matches the ADS-B Squawk code. A message formatter generates a message that includes the ADS-B Squawk code. A wireless transmitter broadcasts the ADS-B Squawk code generated by the message formatter.

Abstract: A system for ensuring Automatic Dependent Surveillance—Broadcast (ADS-B) integrity of an aircraft includes a designated aircraft interrogation area, an ADS-B receiver, and an alerting mechanism. The ADS-B receiver is configured to receive ADS-B data from the aircraft when the aircraft is located in the designated area and to send a signal to the alerting mechanism indicating that the aircraft is in the designated area.

Abstract: A device and method for three-dimensional positioning are provided. The three-dimensional positioning of a common reference point is determined by fusion of supplied measurements, taking into account a lever arm compensation between the reference point, a global navigation satellite system (GNSS) receiver antenna, at least one radar antenna, and an inertial measuring unit.

Abstract: The present invention relates to a method for locating an aircraft (Ak), the said aircraft (Ak) being equipped with at least one device for sending and receiving ADS-B signals, a set of ADS-B communication beacons being deployed on the ground, the position of each of the said ADS-B beacons being known, the said locating method comprising: a step of calibrating the time biases of the ADS-B beacons with a view to correcting the synchronization discrepancies when sending, by means of the calculation of the time discrepancy existing between the ADS-B beacons (B1, B2) upon reception of downgoing ADS-B signals sent by a set of aircraft equipped with at least one device for sending ADS-B signals; a step of calculating the pseudo-distances between the said aircraft (Ak) and the said ADS-B beacons deployed on the ground, on the basis of the upgoing ADS-B signals.

Abstract: The invention relates to a monitoring device and method allowing surveillance of an aircraft in relation to aircraft and/or craft on an airport displacement zone. The invention is a system comprising a dedicated transmitter and receiver to receive the information regarding the location and displacement of the cooperative aircraft and to monitor the location of the said aircraft in relation to the cooperative aircraft. The monitoring application is based on the detection of conflict zones by inter-correlation of constraint surfaces of the airport zone. The invention applies to aircraft carrying communication moans for ADS-B networks for an airport zone monitoring application.

Abstract: A computer-implemented transportation information management system and method permits entry, recording, and transmission of operation and maintenance data related to FAA recordkeeping and recording requirements within an SQL database. A secure website permits entry and display of operation and maintenance data as well as facilitating data input using input devices such as a cellular telephone, a personal digital assistant, a personal computer, and a portable computer. The system outputs aircraft operation and maintenance data, automatic alerts of pilot flight and duty time limitations, and flight tracking and monitoring information via a spreadsheet, electronic mail message, text message, and a completed FAA mandatory reporting requirement forms to the aforementioned data input devices. Operation and maintenance data is automatically and continuously transferred to the FAA to populate FAA flight tracking data systems and air traffic control data system.

Abstract: A method for registering a radar system. The method includes obtaining first values for a location of a target relative to the radar system using radar system initiated signals, obtaining geo-referenced location data for and from the target, obtaining second values for the location of the target relative to the radar system using the geo-referenced location data, computing location registration bias errors for the radar system using the first and second values, and registering the radar system using the computed location registration bias errors.

Abstract: An aircraft avionics system and method for automatically determining an aircraft position. The system and method determine distances to UAT ground stations based on timing signals in transmissions from the UAT ground stations and determines one or more possible positions for the aircraft at which the aircraft is at the determined distances from respective UAT ground stations. The system and method may use three or more UAT ground stations to reduce the possible positions for the aircraft to a single possible position. The system and method also may use dead reckoning or VOR or ADF signals to reduce the possible positions for the aircraft to a single possible position. The system and method may also determine the position of an aircraft by determining true bearings to SSR ground stations and determining the possible positions for the aircraft at which the aircraft is at respective bearings to each SSR ground station.

Abstract: A receiving apparatus for receiving a pulse sequence signal includes a pulse decoding unit which determines, by observing, about a detection signal obtained by performing synchronous detection of a pulse sequence signal modulated by at least a pulse position modulation method, the pulse sequence signal as a pulse string transmitted by on-off keying, and applying a maximum likelihood sequence estimation method using trellis state transition defined by a time interval of the on-off keying and an on-off value concerned, an on-off value of the received pulse string, and a data decoding unit which decode, about the pulse string, information data transmitted by the pulse position modulation method.

Abstract: The present invention relates to a detecting device for detecting an SSR signal having a characteristic structure. The detecting device comprises filtering means matched to the characteristic structure of the SSR signal, and means for maintaining a false-alarm rate at a substantially constant value. The characteristic structure of the SSR signal comprises either a preamble or an initial pulse and a final pulse separated by a fixed dwell time. The means for maintaining a false-alarm rate at a substantially constant value comprise computing means configured to compute a detection threshold on the basis of a signal supplied by the filtering means, and decision means configured to detect the SSR signal on the basis of the detection threshold and of the signal supplied by the filtering means.

Abstract: Methods of protecting location privacy of air traffic communications from unauthorized monitoring of aircraft locations in an uncontrolled airspace include designating a bounded region of uncontrolled airspace; ceasing transmission of a traffic beacon by each aircraft of a plurality of aircraft upon the aircraft entering the bounded region; and updating a unique identifier associated with each of the aircraft while the aircraft is traversing the bounded region.

Abstract: A multilateration system and method includes a plurality of receiver stations for receiving signals from an aircraft, and a controller that derives the position of the aircraft by applying a multilateration process to outputs from the receiver stations. For this purpose, the controller determines the altitude of the aircraft and selects a multilateration process that is to be used for position determination, based on the determined altitude.

Abstract: The invention refers to a secondary surveillance radar, referred to hereinafter as SSR, system (1) for air traffic control. The SSR-system (1) comprises a plurality of secondary radar stations (2) and is adapted for determining a location of an air traffic vehicle within the range of coverage of at least some of the secondary radar stations (2) by means of propagation time measurement of data signals (8) transmitted between the secondary radar stations (2) and a transponder (9) of the air traffic vehicle. Each of the secondary radar stations (2) works on a synchronized local time base. In order to provide for a high-precision synchronisation of the radar stations (2) of the SSR system (1) free of clusters, it is suggested that an SSR system's (1) secondary radar station (2) is synchronized depending on the content of synchronisation signals (10) received by the secondary radar station (2) to be synchronized and broadcast by one of the other secondary radar stations (2) of the SSR system (1).

Abstract: A computer based method, system and computer program product to assign a quality metric to an airspace design and optionally to compare it against design metrics, to determine a comparative quality metric. Factors contributing to quality of the airspace sector design are identified via user input and quantified to calculate a quality metric for the airspace sector design as a function of the quantified factors. Categories for each of the identified factors, and parameters for each of the identified categories are also identified via user input. Each parameter has an associated weight and a range of thresholds with associated multipliers. An associated multiplier from the range of thresholds for each identified parameter is also identified. The identified multiplier is multiplied with the associated weight for each identified parameter. The products for each identified parameter are then summed to obtain a quality metric.

Abstract: In certain embodiments, a method includes receiving first track information comprising data for a particular aircraft track. The method further includes receiving a first radar plot comprising first location information corresponding to first aircraft identification information and first location information corresponding to second aircraft identification information. The method further includes associating the first aircraft identification information with the particular aircraft track. The method further includes accessing historical association information comprising a first association history variable corresponding to one or more previous associations between the first aircraft identification information and the particular aircraft track and a second association history variable corresponding to one or more previous associations between the second aircraft identification information and the particular aircraft track.

Abstract: A secondary surveillance radar with rotating antenna, configured for transmitting interrogations in S or IFF mode and processing the responses to these interrogations. The radar includes an antenna having a lobe with three channels, a Sum channel, a Difference channel and a Control channel, whose transmission means are configured for transmitting interrogation messages over the Sum and Difference channels and whose reception and processing means are configured so as to carry out, aside from conventional detections by the Sum channel, detections by the Difference channel of the responses from the aircraft having been subjected to interrogation by this same channel. The radar also includes means for Space-Time Management configured for generating interrogation messages and determining whether a given message is to be transmitted by the Sum channel, by the Difference channel or by the two channels simultaneously and controlling its transmission by the corresponding transmission channel.

Abstract: A multilateration system and method includes a plurality of receiver stations for receiving signals from an aircraft, and a controller that derives the position of the aircraft by applying a multilateration process to outputs from the receiver stations. For this purpose, the controller determines the altitude of the aircraft and selects a multilateration process that is to be used for position determination, based on the determined altitude.

Abstract: In one aspect, an air and ground vehicle tracking system includes a base station configured to transmit locations of air vehicles to a radio and a GPS receiver disposed in a ground vehicle and configured to derive a location of the ground vehicle. The radio is configured to receive locations of air vehicles, receive locations of other ground vehicles and broadcast a location of the ground vehicle to the base station. The system also includes a display configured to render locations of the air and ground vehicles.

Abstract: A system and technique to derive a position of a non-ADSB equipped aircraft using ADS-B information provided from an ADSB equipped aircraft and bi-static radar processing techniques.

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: Techniques are described that allow information to be acquired by an ADS-B system of an aircraft without the installation of ADS-B dedicated flight crew controls or wired data interfaces in the aircraft. In one or more implementations, a receiver is associated with the ADS-B system in the aircraft. The receiver is configured to receive transmissions from a transponder of the aircraft, such as a radar transponder of a Traffic Collision Avoidance System (TCAS), or the like. Information used by the ADS-B system is extracted from the received transmissions and furnished to the ADS-B transceiver for broadcast over the ADS-B datalink.

Abstract: A receiver in a mode 5 air traffic control system provides amplitude and phase signal outputs a digital data stream containing preamble and flight information from data transmitted from an aircraft. A signal splitter divides the amplitude and phase signal outputs between an odd channel and an even channel that carry odd-numbered pulses and even-numbered pulses, respectively. An odd channel data decoder connected to the signal splitter extracts signals encoded in the odd channel and forms an odd data stream and an even channel data decoder connected to the signal splitter extracts signals encoded in the even channel and forming an even data stream. A preamble correlator correlates the odd and even data streams with a predefined preamble mask to detect potential valid preambles, and preamble decision logic processes signals output from the preamble correlator to identify which of the preambles actually are actually valid.

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: The invention concerns a radar for the control of civil aerial traffic, comprising a secondary radar (100) including a transmitter (110) and a receiver (120), and an antenna (500) of a secondary radar, wherein the signal at 1030 MHz, exiting the transmitter (110), is sent and transmitted into the air by the antenna (500), the antenna (500) receiving a response signal at 1090 MHz and a signal at 1030 MHz of reflection by aircraft, the signal at 1090 MHz being sent to the receiver (120), characterised in that it comprises a radar signal receiving and elaboration unit (200), said receiving and elaboration unit (200) receiving by said antenna (500) the reflection signal at 1030 MHz and being provided with means (300, 400) for the coherent elaboration of the same in order to extract the aircraft position.

Abstract: A method of receiving signals from an aircraft transponder is provided that enables ADS-B signals to be decoded even though parts of the signal may be overlapped due to interference. A plurality of antennas are summed and subtracted in pairs in order to create directional signal channels, which are then assessed for the confidence of the signals received. Where a channel contains a section of the signal of low confidence, the signal from another channel may be substituted for that section.

Abstract: An apparatus and method to generate and detect virtual targets. Position information for one or more virtual targets is calculated onboard a vehicle from real position information obtained from GPS satellites or other external or internal sources. This virtual position information is coded, mixed with a carrier frequency, amplified, and radiated to a nearby test vehicle, such as an aircraft. The amplitude of the radiated signal is adjusted such that the signal containing the virtual position information is received by the test aircraft only. The radiated signal thus adjusted is below the detection threshold of any aircraft further away. The test aircraft decodes the signal and interprets the decoded virtual position information as real aircraft in its vicinity. The coded signals may be structured to comply with the requirements of the FAA's ADS-B system. The apparatus may be mounted on the test aircraft itself, or on a nearby aircraft.