Accuracy analysis of interferometric imaging radar altimeter for baseline oscillation

The interferometric imaging radar altimeter with wide swath will satisfy the requirement of high precision, high temporal and spatial resolution sea surface height (SSH) for sub-mesoscale ocean features. In this paper, the model of spaceborne baseline oscillation on the high accuracy of sea surface height (SSH) is established considering the decoherence due to azimuth shift and antenna beam pointing jitter. A spectral analysis method is employed in order to improve the stability and the accuracy of spaceborne interferometric imaging radar altimeter. Without considering additional on-orbit calibration and validation and other techniques, the RMSE of SSH along the cross-track direction ranges from 0.39cm (in the near of the swath) up to 0.96cm (in the far of the swath) when the vibration amplitude is less than 0.04mm. The RMSE are reduced to 0.08∼0.2cm after the low-frequency vibration amplitude restrained. Finally, the simulation has proven that the accuracy of sea surface height could be improved by restraining the baseline oscillation.