| 摘要 |
There is described an onboard device of a terrestrial vehicle for use in a traffic surveillance system in an airport area comprising means (GPS/SBAS-RX, -Proc) for generating vehicle position data (GNSS Pos), means (ADS-B Proc) for encoding the generated position data and - means (1090ES TX) for transmitting, at a predetermined repetition frequency, radio-frequency signals containing the encoded data. In order to permit the device to be used at a large airport without causing an excessive load of radio emissions, the device also comprises means for memorizing topographical data (Airp Map), which define different zones of the airport area, and emission data (Em-R), which define different repetition frequencies of the signals to be transmitted (Em-R Prof), means (Em-R Corr), for associating emission data (Em-R) with the topographical data (Airp Map) and means (Area Corr) for correlating the position data (GNSS Pos) of the vehicle with topographical data (Airp Map) in order to identify the airport zone in which the vehicle happens to be and to assign the repetition frequency associated with the zone in which the vehicle happens to be as the repetition frequency of the signals to be transmitted. |
