Abstract: Transponder transmissions may be monitored through a direct, shielded connection of an RF coupler to a transponder antenna cable. The transponder interrogated pressure altitude may quickly change and measuring accurate data including position and pressure altitude is critical. A global positioning system (GPS) may be onboard a universal access transceiver (UAT) and may be utilized to correct the transponder interrogated pressure altitude and position. The UAT may transmit data that may include a corrected pressure altitude and a subsequent position to improve air traffic control radar beacon systems (ATCRBS).

Abstract: Transponder transmissions may be monitored through a direct, shielded connection of an RF coupler to a transponder antenna cable. The RF coupler may be added on an antenna cable of an older-style transponder to pick up altitude and reply codes, decode the information and transmit it digitally for use by a separate external monitor. As such, the pilot may be afforded the ability to monitor the older-style transponder's altitude and reply code transmissions to air traffic control so as to determine if a failure of the transponder has occurred. By having the direct connection between RF coupler and the transponder antenna cable, no transmissions of other transponders would be received.

Abstract: Transponder transmissions may be monitored through a direct, shielded connection of an RF coupler to a transponder antenna cable. The RF coupler may be added on an antenna cable of an older-style transponder to pick up altitude and reply codes, decode the information and transmit it digitally for use by a separate external monitor. As such, the pilot may be afforded the ability to monitor the older-style transponder's altitude and reply code transmissions to air traffic control so as to determine if a failure of the transponder has occurred. By having the direct connection between RF coupler and the transponder antenna cable, no transmissions of other transponders would be received.