The repeat-pass interferometric SAR by Pi-SAR(L)

This paper describes the system and experiment of Pi- SAR(L) repeat pass interferometric SAR. To obtain a highquality interferometric image, it is necessary to make two flights on the same pass and observe in the same direction. We built a flight control system utilizing the preinstalled autopilot. This system measures position and altitude precisely with using a differential GPS, and controls the flight pass to be within virtual tube of 10m diameter. The antenna rotation mechanism was also installed to control the observation direction. The repeat-pass flight has been conducted many times. The flights were stable and the deviation was within a few meters for both horizontal and vertical even in the gusty condition. The SAR data were processed in time domain based on range Doppler algorism to make the complete motion compensation. The interferometric image processed after precise phase compensation is shown.