Calibration of PAMIR-Ka Radar Data Using Phase Gradient Method

Abstract:
This paper demonstrates the application of the phase gradient method to estimate the phase of the transfer function of the PAMIR-Ka sensor. After a short review of the system and the phase gradient approach, we perform an estimate of the transfer function for a SAR acquisition of the sensor. The application of a calibration step to the range compression, that is based on the estimated transfer phase leads to an improvement of the point spread function. Two different solutions are compared: On the one hand a correction of an approximated smooth polynomial phase error and on the other hand a compensation of the actual estimated phase values. To get an impression of the variation of the phase behavior of different channels and acquisitions, we also apply the phase gradient method to the remaining channels of the acquisition as well as a second acquisition and compare the results.