Orbit registration between wide swaths of passive sensors and narrow traces of active sensors

The paper proposes an approach for pixel-by-pixel orbit registration between wide swaths of passive sensors and narrow traces of active sensors, where a rough-to-fine process is implemented step by step. Take a granule of one passive sensor and the corresponding orbit of an active sensor as example. First, a part of the trace is extracted according to the latitude and longitude of the granule. Second, the granule is constrained roughly on the basis of the latitude and longitude of the extracted trace. Finally, a cost function v
_err
of latitude and longitude is defined and the most matching pixel is selected from the constrained granule for each pixel of the active sensor along the extracted trace according v
_err
and a given threshold. Moderate Resolution Imaging Spectroradiometer (MODIS) on Aqua and Cloud Profiling Radar (CPR) on CloudSat are chosen to validate the proposed method. Estimated results are compared with geographic data provided by CloudSat team, demonstrating that the algorithm performs well.