A a method for managing a secondary radar operating in Mode S, the method includes a) a detection in “seeking mode”, the “seeking mode” being implemented until an aircraft is detected by the secondary radar; b) a detection in “tracking mode”, the “tracking mode” being implemented if a valid response to a roll-call interrogation was detected in “seeking mode”; the method comprising an intermediate step a1), which is executed between the detection in “seeking mode” and the detection in “tracking mode”, the intermediate step comprising: detecting the presence or absence of the reply of the aircraft in a noise window of the secondary radar; carrying out at least one roll-call interrogation, using the first monitoring window, if the reply of the aircraft is not located in the noise window.

Various avionics systems may benefit from appropriate integration of distance measurement equipment, traffic collision avoidance systems, and transponders, with the distance measurement equipment using a dedicated antenna. A system can include a transponder processor. The system can also include a top antenna receiver configured to connect to a top antenna. The transponder processor can be configured to communicate using the top antenna. The system can also include a bottom antenna receiver configured to connect to a first bottom antenna, wherein the transponder processor is configured to communicate using the first bottom antenna. The system can further include a distance measure equipment processor integrated with the transponder processor and configured to measure distance using a second bottom antenna.

A method for detecting conflicts in the II/SI identification code of radars nearby a secondary mode-S radar, includes at least: a first step wherein the radar detects unsolicited unsynchronized replies, i.e. fruits, in a region of extended radar coverage; a second step wherein the radar detects a conflict in II/SI code by analyzing geographic regions of radar coverage common to the radar and to at least one nearby radar, a conflict being detected if the radar: detects, in the region of extended coverage, the presence of fruits that have as source the nearby radar; observes the absence of fruits caused by the nearby radar in that region of radar coverage of the radar which does not overlap with the region of radar coverage of the nearby radar; the region of overlap between the radar coverage of the radar and the radar coverage of the nearby radar forming a region of conflict in II/SI code.

The present invention provides a low-cost and low-volume mode A/C/S transponder positioning system to detect the position of a target aircraft, or intruder, outside the range of a secondary surveillance radar system. The system uses a signal of the intruder to pinpoint the location of the intruder. The system can be used on both the ground and on an aircraft in a full 360 degree range around the system.

Various avionics systems may benefit from appropriate integration of distance measurement equipment, traffic collision avoidance systems, and transponders, with the distance measurement equipment using a dedicated antenna. A system can include a transponder processor. The system can also include a top antenna receiver configured to connect to a top antenna. The transponder processor can be configured to communicate using the top antenna. The system can also include a bottom antenna receiver configured to connect to a first bottom antenna, wherein the transponder processor is configured to communicate using the first bottom antenna. The system can further include a distance measure equipment processor integrated with the transponder processor and configured to measure distance using a second bottom antenna.

The radar includes an antenna having a radiation pattern forming a sum channel, SUM, a radiation pattern forming a difference channel, DIFF, and a pattern forming a control channel, CONT, a first transmission and reception chain being associated with the SUM channel and a second transmission and reception chain being associated with the CONT channel, a reception channel being associated with the DIFF channel. Each of the transmission and reception chains is able to transmit and to receive simultaneously, the transmission chain comprising a filtering operation that filters signals transmitted at 1090 MHz and the reception chain comprising a filtering operation that filter signals transmitted at 1030 MHz, in such a way that the chains operate independently of one another.

The secondary radar includes an antenna having a radiation pattern forming a sum channel, designated SUM, a radiation pattern forming a difference channel, designated DIFF, and a pattern forming a control channel, designated CONT, the targets are located by implementing the following steps: detecting ADS-B squitters received via the CONT channel, via the SUM channel and via the DIFF channel; measuring at least the power of the squitters and their azimuth with respect to the radar; the location of a target transmitting ADS-B squitters being computed by exploiting at least the detection of one ADS-B squitter, in light of the latitudinal and longitudinal position of the radar and of the azimuthal measurement with respect to the radar, the position cell, designated the CPR cell, coded in the squitter being selected via the azimuthal measurement.

In some examples, a system that mounts on a vehicle includes a transceiver configured to transmit a first surveillance message including a first value for a quality parameter, wherein the first value indicates a first level of integrity or accuracy for the first surveillance message. The transceiver is also configured to receive a reply message to the first surveillance message. The system also includes processing circuitry configured to determine a second value for the quality parameter in response to the transceiver receiving the reply message, wherein the second quality parameter indicates a second level of integrity or accuracy for surveillance messages transmitted by the transceiver, and wherein the second level of integrity or accuracy is higher than the first level. The transceiver is configured to transmit a second surveillance message including the second value for the quality parameter in response to the processing circuitry determining the second quality parameter.

A radio transmission device for the radio transmission of an interrogation signal based on a signal to be amplified is provided. This method comprises a generator for generating a signal to be amplified, and a selection block for selecting a type of interrogation signal to be transmitted from among at least two different types of signals. The generator for generating a signal to be amplified is configured so as to allow transmission of the signal to be amplified so as to generate the interrogation signal corresponding to the selected type of interrogation signal.

A radar includes an antenna having a radiating pattern forming a sum channel, a radiating pattern forming a difference channel and a pattern forming a control channel, and generates at least interrogation messages on the sum channel and interrogation messages on the control channel; transmits messages via the sum channel and via the control channel respectively, and receives and processes signals received via the sum, difference, and control channels, configured for detecting replies of targets on the signals received via the sum and difference channels and carrying out monopulse processing and RSLS processing on the replies. The transmission is configured such that, for each target, the width of the beam for transmitting interrogations and receiving mode S selective replies is controlled based on the movement window of the target and position of the axis of the antenna in the window, to provide detection of the target by reducing the number of selective interrogations by a selective sub-interrogation of the target while ensuring precise positioning in azimuth: by pre-locating the target at the edge of the main reception lobe of the antenna by deviation measurement between the signals received on the difference and sum channels; and by selectively re-interrogating the pre-located target in mode S by calculation of the roll-call signal nearest to the centre of the main lobe to ensure precision in azimuth, without any other unnecessary supplementary interrogation.