In-situ multispectral and bathymetric measurements over a supraglacial lake in western Greenland using a remotely controlled watercraft

We report concurrent in-situ multi-spectral and depth measurements over a supraglacial lake in West Greenland, collected by means of a remotely controlled boat equipped with a GPS, a sonar and a spectrometer. We focus our attention on the analysis of some of the key parameters widely used for multispectral spaceborne bathymetry, namely the lake bottom albedo and the water attenuation coefficient. The analysis of in-situ data highlights the exponential trend of the water-leaving reflectance with lake depth. The values of the attenuation factor are obtained from in-situ data and compared with those computed using approaches proposed in the literature. Also, the values of the lake bottom albedo from in-situ measurements are compared with those obtained from the analysis of reflectance of shallow-waters. Finally, we quantify the error between in-situ measured and satellite-estimated lake depth values for the lake under study.