Baseline estimation with block adjustment considering ground control point errors for multi-pass dual-antenna airborne INSAR

Baseline estimation is a necessary step in processing of InSAR. The theory of block adjustment is introduced in baseline estimation to reduce the needed number of ground control points (GCPs). The main disadvantage of the method is that it has to extract substantial tie points (TPs) in the overlapping areas. If all TP heights are seen as unknown parameters, the coefficient matrix in normal equation will be quite large but sparse. In addition, the measurement errors may exist in GCPs, which can be propagated to baseline parameters. In this paper, a baseline estimation method with block adjustment considering GCP errors is proposed. The heights of GCPs are seen as observations with certain weights and then virtual error equations are established for both GCPs and TPs. Experiments performed on Chinese dual antenna airborne InSAR data validate the proposed method.