Polarimetric Sar Calibration Algorithm

Polarimetric SAR is sensitive to target shape, structure, texture and other physical characteristics of target,thus it has been widely used in the field of remote sensing. Polarimetric SAR system under the influence of channel crosstalk, amplitude and phase imbalance, the system noise and environmental clutter and other complex factors,the raw data is no longer accurately reflect the true target characteristics and scattering mechanism,Only if after the calibration of polarimetric SAR data, radar scattering model which was built could extract target information Faraday rotation on the polarimetric combination of amplitude and phase, polarimetric data fusion, interpretation and other applications makes sense, and the advantages of polarimetric SAR could be foregrounding.Therefore, the polarimetric calibration technique is essential to polarimetric SAR systems'application, in recent years it has become the difficult and hotspot for polarimetric SAR technology. In the paper, the research on polarimetric calibration is followed closely and deeply studied. The mayor work in this paper is as followed:(1) Some of the basic theory of radar polarization are described, which Include the electromagnetic wave polarimetric characterization, polarization characteristic response. Among the important physical concepts, polarization characteristic response is the visual method which could describe the polarimetric calibration result.(2) Based on Polarimetric Spaceborne SAR, analyzed the most general and complete electromagnetic wave transmission model, summed up the polarimetric calibration of important physical concepts which are involved in this paper and several representative polarization SAR calibration algorithm.(3) Built a kind of mathematical model within small Faraday rotation angle approximation. Proposed a polarimetric calibration iterative algorithm based on Whitt method which is able to solve Faraday rotation couling in some scale. Promoted the polarimetric calibration model under the condition of dual-polarization SAR, and a preliminary attempt in the dual-polarized SAR calibration field is done.(4) Promoted the polarimetric calibration model within Faraday rotation effect, A genetic polarimetric calibration algorithm based on the distribution target which can effectively solve the the Faraday coupling problem in the polarimetric calibration.(5) Assessed the impact of system parameters estimation error on the covariance matrix under the condition of full-polarimetric SAR, established the polarimetric SAR calibration disturbance model which could used for analysis the impact of covariance matrix error. And analyzed the effect on polarimetric application within polarimetric calibration error which used polarimetric classification as an example.