A Calibration Method for Airborne InSAR Applied to Large Areas with Sparse GCPs

High-precision height acquisition needs to correct the interferometric parameters errors by interferometric calibration for Interferometric SAR (InSAR) system. The traditional interferometric calibration method needs more Ground Control Points (GCPs) to reduce the influence of systematic random errors to the calibration precision, but it is very difficult to dispose GCPs in the field with complicated terrains, some areas probably only have little GCPs or even no GCPs and the traditional interferometric calibration method is inapplicable to this situation. A new calibration method is proposed for airborne InSAR based on block adjustment, which introduces the block adjustment theory in Photogrammetry to the processing of InSAR system calibration, through the joint multi-strip processing the method can be used to calibrate the interferometric parameters for airborne InSAR applied to large areas with sparse GCPs. Moreover, the problem of inconsistent height in the overlapping areas caused by the traditional calibration method is also solved. Finally, a joint calibration is adapted to the simulative data of three strips from the highland and the results confirm the validity and rationality of the proposed method.