Assessing the Accuracy of LiDAR Surveys for Geodetic MassBalances in Glaciers of Chilean Central Andes

Abstract

Repeat high-resolution (1m2) airborne light radio detection and ranging (LiDAR) laser altimetry data (2009-2015) for geodetic mass balances on five
mountain glaciers, and its near-time ground-control points (GCPs) surveyed by global positioning system (GPS) on glacier surface (2015), were firstly
used for accuracy assessment of elevation changes (dh/dt) in Chilean Central Andes. The inverse distance weighting algorithm (IDW) reproduced the glacier surface topography with the minimum root mean square error (RMSE) when a digital elevation model (DEM) is created. High thinning rates in meter water equivalent (mw.e.) were found at Echaurren Norte and San Francisco glaciers, two partially covered low-elevation glaciers, with -1.69 ± 0.14 m and -1.3 ± 0.19 m, respectively, while at Yeso and Bello, two high-altitude clean-ice glaciers, a more moderate rate of -0.65 ± 0.24 m and -0.66 ± 0.14 m was derived. Likewise, Pirámide is a debris-covered glacier with a negligible elevation change. Although systematic and random errors using glacierized nd non-glacierized terrain shows neglected differences, inaccuracies induced by pre-processing interpolation parameters yield positive and negatives differences of up to 2.04 m which leads to 3% biases in the geodetic mass balances.