A robust tracking system for imaging radar altimeter

The capability of precise range tracking is an important characteristic for an oceanic radar altimeter, different from other tracking radars. Up to now, however, all of the operational spaceborne radar altimeters can only be applied to the ocean because their tracking algorithms are based on an assumed echo model, and usually is Brown´s (1977) model. But for the land case, we can not get a specified echo model, so the model-based tracking algorithm is not valid any longer. In this paper, we perform a study on a model-free tracking algorithm, i.e. the OCOG (offset center of gravity) algorithm. This is a robust tracking algorithm and is applied to an imaging altimeter, which is being researched. The imaging altimeter can be used both for ocean and land applications. The error characteristics of this algorithm are studied and a tracking simulation is given.