Facilitating comparisons between ICESat waveforms and ICESat-2 point data

Abstract:

A major challenge for ICESat-2 is how to make meaningful comparisons between the photon counting point data and legacy ICESat waveforms. Such comparisons are essential in quantifying changes in ice sheets across the last decade, but are complicated by the disparate data that is produced by the two instruments. These comparisons are especially important over complex surfaces such as crevasses, which are among the most dynamic ice sheet features and are often indicative of underlying changes in the ice stress fields. We use a density based algorithm (Ordering Points To Identify the Clustering Structure, or OPTICS) to filter photon counting data from two separate Photon-counting LiDAR instruments; the filtered point data is then weighted and convolved to simulate ICESat waveforms. Linking ICESat waveforms with ICESat-2 photon counts is needed in order to understand changes in ice sheet dynamics, and will help quantify the temporal scale of changes occurring in Greenland’s outlet glaciers.