Polarimetric Interferometric Sar Calibration Technology

Polarimetric SAR interferometry (POL-INSAR), which combines SAR polarimetry with SAR interferometry, has become a very important direction of SAR application development. Polarimetric SAR interferometry has significant applications in many domains, such as terrain mapping, detection of subtle changes on earth's land, estimation of biology quantity. However the application of Polarimetric SAR interferometry greatly depends on the level of the calibration technique. Presently the calibration of Polarimetric SAR interferometry is still limited with the theoretic and experimental researches. In this paper, we have a deep study of the Polarimetric SAR interferometry calibration model and the calibration algorithm.The theory and technology of Polarimetric SAR calibration and Interferometric SAR calibration were studied and some problem in them were analyzed, such as system model, calibration model and calibration algorithms, and so on. Based on above all, the theories of polarimetric SAR interferometry were studied, the Polarimetric SAR interferometry system model and the error source of the system were analyzed, and the Polarimetric SAR interferometry calibration model was lucubrated. Presently the calibration of Pol-InSAR is still limited with the suppose of homogeneous flat model. This paper proposes a new improved algorithm using the sensitivity equation based on the error source analysis. The algorithm gets the parameter by the iterative method from the sensitivity equation. Not only it improves the precision but also overcomes the flaw of homogeneous flat model, hence it is more applicable. Through erecting the mathematic model, a method of calibration requirement was presented.The studies were made further by means of simulation. The target scattering, and the Polarimetric SAR Interferometry were simulated and the simulation data were used to test and analyze the provided algorithm. The results show that the precision of the mean elevation is improved into 1.5m from the 10m of the conventional algorithm. Through experiments, the relation between cross talk, channel imbalance and the RMS of terrain elevation.By the theory research and simulation experiments, it has been proved that the Polarimetric SAR interferometry calibration model is correct and the performances of the new improved algorithm is better than the conventional algorithm.