David Harding

NASA/GSFC, Laboratory for Planetary Geodynamics
NASA’s ICESat-2 spaceflight mission will employ a new laser altimetry measurement approach to monitor changes in ice sheet elevations and sea ice thickness and to globally map vegetation height. The ICESat-2 instrument, ATLAS, will use a multi-beam, micropulse, photon-counting technique at 532 nm that has the potential to provide enhanced capabilities as compared to the first ICESat mission’s conventional single-beam, 1064 nm, analog-waveform measurements. However, because there is less experience using this technique and it has not previously been done from orbit there are uncertainties about the quality of the measurements to be acquired by ATLAS. The airborne Slope Imaging Multi-polarization, Photon-counting Lidar (SIMPL) is being used to advance understanding of the micropulse measurement technique. SIMPL adapts the polarimetric, two-color approach used by some atmospheric lidars to observations of the Earth's surface. The single-photon, high-precision ranging measurements are used to understand scattering interactions with snow, ice, water and vegetation at 532 nm and 1064 nm in order to prepare for the ICESat-2 mission. Results will be shown for Lake Erie ice cover, a surrogate for sea ice, and for forested sites observed during the 2011 Eco3D P-3 mission flown along with GSFC's CAR and DBSAR instruments.