Abstract: A method for arranging a set of antennas capable of transmitting or receiving in a radio frequency range in an existing aerodyne implemented either during an initial installation operation, or in a subsequent maintenance or update operation is disclosed. The method includes removing at least one component of a structural element external to the bearing surface of the existing aerodyne, the component being substantially transparent to the radio frequency range; installing the set of antennas in a zone exposed by the removal in the step; fitting an electronic and electrical harness connecting the set of antennas to a radio communications system and to a power supply inside the fuselage; re-forming the external structural element in such a way as to cover the installed set of antennas.

Abstract: A method for receiving an ADS-B message is disclosed including a synchronisation phase for detecting the start of the message and a decoding phase for recovering a bit stream corresponding to a block of data in the message. The synchronisation phase is based on determining a sequence of log-likelihood ratios having the greatest likelihood of corresponding to a sequence of symbols expected from a preamble of the message. Each log-likelihood ratio corresponds to a ratio between the respective probabilities that a symbol of the signal received corresponds to one of two possible values for a symbol. The decoding phase applies a belief propagation algorithm to a sequence of log-likelihood ratios respectively associated with the symbols in the block of data in the message, with an optimised parity matrix of the cyclic redundancy code of the message.

Abstract: A method for receiving an ADS-B message is disclosed including a synchronisation phase for detecting the start of the message and a decoding phase for recovering a bit stream corresponding to a block of data in the message. The synchronisation phase is based on determining a sequence of log-likelihood ratios having the greatest likelihood of corresponding to a sequence of symbols expected from a preamble of the message. Each log-likelihood ratio corresponds to a ratio between the respective probabilities that a symbol of the signal received corresponds to one of two possible values for a symbol. The decoding phase applies a belief propagation algorithm to a sequence of log-likelihood ratios respectively associated with the symbols in the block of data in the message, with an optimised parity matrix of the cyclic redundancy code of the message.

Abstract: A method for detecting useful signals in an overall signal. Each useful signal may be affected with a frequency drift. In the detection phase, frequency spectra for detecting the overall signal for multiple detection time windows are calculated and useful signals according to the detection frequency spectra are detected. In the estimation phase, for each useful signal detected: the frequency of the overall signal for multiple frequency drift values is reset. In the estimation phase, for each useful signal detected, a frequency spectrum is calculated for the estimation of the overall signal for each frequency drift value over an estimation time window having the useful signal detected and of a duration higher than the detection time window. In the estimation phase, for each useful signal detected, the frequency drift is estimated affecting the useful signal detected according to the estimation frequency spectra.

Abstract: A method for detecting useful signals in an overall signal. Each useful signal may be affected with a frequency drift. In the detection phase, frequency spectra for detecting the overall signal for multiple detection time windows are calculated and useful signals according to the detection frequency spectra are detected. In the estimation phase, for each useful signal detected: the frequency of the overall signal for multiple frequency drift values is reset. In the estimation phase, for each useful signal detected, a frequency spectrum is calculated for the estimation of the overall signal for each frequency drift value over an estimation time window having the useful signal detected and of a duration higher than the detection time window. In the estimation phase, for each useful signal detected, the frequency drift is estimated affecting the useful signal detected according to the estimation frequency spectra.