Theoretic error analysis of split-gate tracker in satellite radar altimetry

A theoretical analysis of the altimeter split-gate height tracker error is carried out in this paper. The principles of altimeter split-gate tracker are reviewed, and the discriminative curve of the tracker is derived. It is shown that the antenna parameters have little influence on the slope of discriminative curve. The height noise of the tracker is analyzed, assuming there is no other noise in the instrument. It shows that the AGC gate noise contributes much in the overall tracker noise in high sea state condition, so a long AGC gate is preferable. Finally, the 1s-averaged height noise level in a typical sea state (SWH=4 m) is calculated, and the error specification (<2 cm) is proved to be met.