Spaceborne imaging altimeter for topographic mapping

A new conceptual spaceborne radar altimeter is introduced, which can be used not only for oceanic observation as a conventional altimeter but also for ice and land topography mapping. This new sensor is different from the recently proposed scanning altimeter and SAR altimeter. The basic principle of this sensor can be concluded as: (1) off-nadir looking, (2) model-free tracker based on off-set center of gravity (OCOG) algorithm, (3) synthesize the aperture along azimuthal direction, (4) Interferometric information obtained through two antennae and height value corresponding to pixel can be derived. The authors introduce the system design and data processing. They propose a small satellite constellation for global topography mapping