LT-1 Baseline Calibration Method Based on Improved Baseline Calibration Model.

Interferometric synthetic aperture radar (InSAR) is an effective digital elevation model (DEM) generation tool. High-precision InSAR DEM requires an accurate baseline. The baseline accuracy can reach 2 mm in the TanDEM-X mission. However, compared with the X-band, the L-band has the characteristics of long wavelength, strong penetrability, and low backscattering coefficient, which leads to the elevation error caused by the penetration depth and the signal-to-noise ratio (SNR) decorrelation cannot be ignored. Therefore, this paper proposes a baseline calibration method with compensation for additional height error caused by penetration depth and SNR decorrelation.Aiming at the baseline calibration of L-band InSAR TwinSAR-L (LT-1), this paper calculates the calibration accuracy of proposed calibration method by using Advanced Land Observing Satellite-2 (ALOS-2) data when taking desert as the calibration field. The results show that the baseline error before additional elevation error compensation is 2.6 mm (1d), and reduces to 0.85 mm (1d) after compensation. Therefore, the baseline calibration method in this paper can effectively realize the baseline calibration of LT-1.