Interferometric Calibration of Wide Swath Altimeters with Inclined Baseline Using Inland Lakes

Wide swath altimeters are a new generation of radar altimeters, which can provide elevations of both the ocean and the inland surface waters with unprecedented swath and spatial resolution. Interferometric calibration that gives estimates of the unknown variations of the baseline length, the baseline roll angle, and the phase offset, are essential to deriving topography accurately. Current methods are mainly developed on a cross-track height error model for systems with a horizontal baseline. However, for altimeters with a deliberately-inclined baseline, the height error model turns into a complicated form. This paper proposes a calibration method for wide swath altimeters with an inclined baseline using phase measurements from large inland lakes. The validity of the method has been confirmed by simulated buoy samples and together with real data acquired by Interferometric Imaging Radar Altimeter (InIRA), which was equipped on the Tiangong-2 space laboratory of China.