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DDC:
550 - Earth sciences
Abstract:
Satellite Radar Altimetry (RA) can provide highly accurate measurements of the sea surface height (SSH). SSH is used for the calibration and as a ground truth for the Shuttle Radar Topography Mission (SRTM) X-SAR instrument. Since altimeter missions and SRTM fly with different ground patterns, a composite "Synthetic" Altimetry Data (SAD) model is developed to provide the instantaneous SSH at the time and position of the SRTM X-SAR data takes. The SAD model is composed of a static and a time variable part of the SSH. The static part consists of a mean SSH model, which is calculated from RA data. The time variable part is reconstructed from models. Since the accuracy of the SAD model is strongly dependant on the location, a static mean error model is estimated which is based on the comparison of independent RA along track measurements and the SAD model. The error model confirms the accuracy of the SAD model at most locations and it helps to identify the areas, where the stipulated X-SAR calibration requirement of one meter cannot be fulfilled.
