Development of Onboard Digital Elevation and Relief Databases for ICESat-2

The Ice, Cloud, and land Elevation Satellite-2 (ICESat-2), the successor mission to ICESat, is planned to launch in 2017. The ICESat-2 spacecraft will carry the Advanced Topographic Laser Altimeter System (ATLAS). ATLAS will be the most precise space-based photon-counting laser altimeter to date, and its measurement strategy requires the development of sophisticated onboard receiver algorithms to ensure success in downlinking the science data in the telemetry and the subsequent development of science data products. A set of databases, the digital elevation model and digital relief map (DRM), has been developed for use in ATLAS onboard signal processing. A number of elevation data sets were combined to create the global elevation and relief databases, and a method for calculating along-track relief from raster elevation data sets was devised. A technique for deriving the accuracy of the DRM relative to the magnitude of relief was developed to inform the selection of DRM margin values.