Method for controlling message transmission power implemented by a system for preventing collisions of aircraft during flight

A method of controlling a transmission power of messages used by a traffic alert and collision avoidance system, said system including an anti-collision apparatus and a transponder equipping each aircraft,

• said method including the following steps carried out by said anti-collision apparatus of a first aircraft:
• transmitting request messages in the form of radiofrequency signals carrying said messages, and
• receiving radiofrequency signals carrying response messages transmitted by said transponder in response to said request messages,
• said method further including the following steps carried out by said transponder of a second aircraft:
• receiving the radiofrequency signals carrying request messages transmitted by said anti-collision apparatus, and
• transmitting the radiofrequency signals carrying response messages in response to request messages,
• said method further including the following steps carried out by said anti-collision apparatus of said first aircraft:
• measuring at least a value, termed a quality value, of a magnitude representing a quality of reception of the radiofrequency signals carrying response messages transmitted by said transponder and
• encapsulating data representing said quality value or values in said request message to be transmitted by said anti-collision apparatus,
• said method further including the following steps carried out by said transponder of said second aircraft:
• controlling the transmission power of the radiofrequency signals carrying said response messages as a function of the quality value or values encapsulated in the request messages transmitted by said anti-collision apparatus of said first aircraft.

A power control method implemented by an anti-collision apparatus of a traffic alert and collision avoidance system of an aircraft, comprising:

• generating a request message,
• transmitting in the form of radiofrequency signals the request message resulting from the generating step,
• receiving the radiofrequency signals carrying a response message transmitted by a transponder of another aircraft in response to said request message, and
• measuring a quality of the radiofrequency signals received from said transponder and carrying the response message,
• data representing the quality value or values measured being encapsulated in a new request message generated in a new step of generation of a request message.

A traffic alert and collision avoidance system for preventing collision of a first aircraft and a second aircraft, of the type including an anti-collision apparatus equipping said first aircraft and a transponder equipping said second aircraft, said anti-collision apparatus including

• a transmission system for transmitting request messages in the form of radiofrequency signals carrying said messages, and
• a receiver for receiving radiofrequency signals carrying response messages transmitted by said transponder in response to said request messages,
• said transponder including
• a reception system for receiving radiofrequency signals carrying request messages transmitted by an anti-collision apparatus, and
• a transmitter for transmitting radiofrequency signals carrying response messages in response to request messages,
• wherein said transponder includes a measurement unit for measuring at least a value, termed a quality value, of a magnitude representing a quality of reception by the reception system of the radiofrequency signals carrying request messages transmitted by an anti-collision apparatus and an encapsulation unit for encapsulating said quality value or values in said response message, and
• wherein said anti-collision apparatus includes a control unit for setting the transmission power of the transmission system as a function of the quality value or values encapsulated in the response messages transmitted by said transponder.