The transponder data recorder: Implementation and first results

We have designed, implemented, and tested a flexible receiving and processing multichannel system for signals in the 1,090-MHz band with significant air traffic management applications in surveillance and communication. Thanks to a wide bandwidth and a large dynamic range, with four linear channels plus a logarithmic channel, this TDR allows us to record the signals of interest with minimal distortion, from sources whose distance from the antenna sys-tem ranges from a few tens of meters up to hundreds of kilometers. From the recorded signals, it is possible: 1) to characterize the traffic in the 1,090-MHz band, and 2) to test the effectiveness of different source separation algorithms, either based on space diversity or based on frequency diversity. The system permits a higher degree of automation and higher quantity of data acquisition than some previous experimental systems.