Abstract: A method for collecting at least one message received from at least one terminal, the method being performed on-board a satellite, includes receiving, continuously in time, a main signal over a main frequency band, sampling the received main signal, searching, in the samples of the main signal, a preamble signal emitted by the terminal, the preamble signal being included in a preamble frequency band, the preamble frequency band being included in the main frequency band, if a preamble signal has been found at the procedure of searching, storing data digital samples of at least one data signal in the memory of the satellite, the data signal being included within at least one data frequency band comprised in the main frequency band, the digital samples resulting from a sampling of the received signal within the data frequency band.

Abstract: A system for surveying aircraft present in an area covered by at least one communication satellite, the aircraft transmitting signals conveying surveillance messages. The coverage area consists of multiple spots, the satellite is configured to periodically apply a switching sequence, the sequence consisting of multiple switching phases, a switching phase corresponding to a duration during which the signals transmitted by the aircraft present in at least one spot are processed by the satellite in such a way as to detect surveillance messages, and the sequence is adapted to allow for the detection, during a predetermined period Tup, of at least one surveillance message by aircraft present in the coverage area.

Abstract: A system for surveying aircraft present in an area covered by at least one communication satellite, the aircraft transmitting signals conveying surveillance messages. The coverage area consists of multiple spots, the satellite is configured to periodically apply a switching sequence, the sequence consisting of multiple switching phases, a switching phase corresponding to a duration during which the signals transmitted by the aircraft present in at least one spot are processed by the satellite in such a way as to detect surveillance messages, and the sequence is adapted to allow for the detection, during a predetermined period Tup, of at least one surveillance message by aircraft present in the coverage area.