A synthetic moving target generator for calibration of Radarsat 2 Moving-Object Detection Experiment (MODEX)

The Moving-Object Detection Experiment (MODEX) of the Radarsat 2 platform will allow object motion extraction and measurement by partitioning the radar antenna into fore and aft apertures. Accurate extraction of object motion requires compensation to produce two equivalent radar channels. Calibration of MODEX signals is best accomplished by a transponder that receives and measures the signal transmitted by the satellite and uses the captured radar waveform to generate moving point-target signals with precisely known properties. We are proposing to use a computed approach to implement a synthetic target generator (STG) as a transponder for the motion calibration of Radarsat 2 MODEX. With this approach, the incoming pulses are digitized, manipulated using a fast digital signal processor (DSP) to synthesize signals simulating moving point-targets, and then converted back to analog for transmission. This paper reviews theoretical considerations for the synthesis of moving-object signals, demonstrates the concepts with simulations, and discusses implementation issues.