Analysis the Parameters’ Sensitivity on Airborne SAR Interferometric Calibration
|School||Central South University|
|Course||Cartography and Geographic Information Systems|
|Keywords||synthetic aperture radar (SAR) interferometric SAR calibration sensitivity equation target elevation model boresight mode squint mode|
Airborne synthetic aperture radar (SAR) interferometry (InSAR) technique was one of the means to obtain digital elevation model (DEM), the system parameters’deviation of SAR Interferometry influenced the accuracy of DEM, it was necessary to amend these deviations, which was the so-called interferometric calibration. It needed to determine the target location elevation model which reflected the relationship between parameters and the ground elevation, then obtain the degree of influence on the height, determine the calibration parameters of interference in the interferometric calibration. These practices were essential to the SAR interferometric calibration. Therefore, the author mainly studies and analyzes the target location model and the main parameters of the sensitivity model. The main work is as follows.1. The author introduces the oretical knowledge to establish the relevant target location model, and analyzes the influence when using plane instead of spherical in the airborne SAR interferometry and summarizes the concept of boresight and squint mode about side-looking SAR.In order to utilize and calculate conveniently, the author shows the conversion relationship between SCH and WGS-84 coordinate system.2. The author explains the target elevation model of boresight mode, introduces the vector orthogonal decomposition methods, including Malloqui’s vector orthogonal decomposition method. The spherical wave and plane wave are analyzed, and then the author presentes two cases of elevation sensitivity equation.3. The target elevation models of boresight mode and squint mode are calculated by the data respectively. When there are aircraft attitude angles, the model which is calculated under the boresight mode is not suitable anymore. The quantitative research shows that the key angle of imflucing elevation is roll angle, followed by the pitch angle. The sensitivity of the system parameters is calculated.At last the author combines with the results of existing researchers and determines the most important calibration parameters in the SAR interferometric calibration.