Space-based photon-counting laser altimetry for global applications

NASA's Ice, Cloud and Land Elevation (ICESat-2) satellite is planned for launch in 2018 with the goal of providing a global distribution of elevation measurements to support many Earth science applications. The primary science mission is focused on the Polar Regions and will provide data to help understand controlling mechanisms of polar ice sheet mass balance, and investigate ice-ocean-atmosphere exchanges of mass, energy and moisture as it relates to sea ice thickness. ICESat-2 will also allow for terrain and canopy height retrievals as it operates continually throughout its orbit. The satellite will utilize a laser altimeter that provides signal detection sensitivities on the photon-level. This instrumentation allows for lower power and weight requirements to support a high repetition rate, multiple-beam configuration for improved spatial coverage as compared to previous missions. In order to develop the geophysical data product algorithms in preparation for launch, simulated data sets have been produced based on the statistical representation of the expected system performance. These data allow for data product quality analysis over specific types of ecosystems. This is of particular interest for vegetated regions, where canopy cover characteristics will directly affect the ability to retrieve terrain heights. This paper will discuss the expected ICESat-2 land/vegetation data product quality a selected ecosystem.