The Performance of ICESat-2's Strong and Weak Beams in Estimating Ground Elevation and Forest Height

Abstract

The Ice, Cloud and Land Elevation Satellite-2 (ICESat-2) mission provides effective data for measuring global ground elevation and forest height. Unlike the ICESat, ICESat-2 emits three pairs of beams. Each pair includes a strong beam and a weak beam with an energy ratio of 4:1. To evaluate the performance of ICESat-2's strong and weak beams in estimating ground elevation and forest height, the ICESat-2 data in four different scenarios were analyzed; 1) ICESat-2's strong beams in the daytime, 2) ICESat-2's weak beams in the daytime, 3) ICESat-2's strong beams in the nighttime, and 4) ICESat-2's weak beams in the nighttime. The results indicate that the weak beams perform as well as strong beams in estimating ground elevations due to high coefficient of determination (R2) values and low root-mean-squared error (RMSE) values regardless of the daytime and nighttime data. While for forest height estimation, ICESat-2's weak beams perform worse than strong beams and the daytime data perform worse than the nighttime data. These results suggest that all ICESat-2 data are suitable for ground elevation extraction, while the ICESat-2's weak beams in the daytime are not suited to estimate forest height.