 |
| Titel |
In-situ multispectral and bathymetric measurements over a supraglacial lake in western Greenland using a remotely controlled watercraft |
| VerfasserIn |
M. Tedesco, N. Steiner |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1994-0416
|
| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 5, no. 2 ; Nr. 5, no. 2 (2011-05-27), S.445-452 |
| Datensatznummer |
250002435
|
| Publikation (Nr.) |
 copernicus.org/tc-5-445-2011.pdf |
|
|
|
|
|
| Zusammenfassung |
| Supraglacial lakes form from meltwater on the Greenland ice sheet in
topographic depressions on the surface, affecting both surface and
sub-glacial processes. As the reflectance in the visible and near-infrared
regions of a column of water is modulated by its height, retrieval
techniques using spaceborne remote sensing data (e.g. Landsat, MODIS) have
been proposed in the literature for the detection of lakes and estimation of
their volume. These techniques require basic assumptions on the spectral
properties of the water as well as the bottom of the lake, among other
things. In this study, we report results obtained from the analysis of
concurrent in-situ multi-spectral and depth measurements collected over a
supraglacial lake during early July 2010 in West Greenland (Lake Olivia,
69°36'35" N, 49°29'40" W) and aim to assess some of the underlying
hypotheses in remote sensing based bathymetric approaches. In particular, we
focus our attention on the analysis of the lake bottom albedo and of the
water attenuation coefficient. The analysis of in-situ data (collected by
means of a remotely controlled boat equipped with a GPS, a sonar and a
spectrometer) highlights the exponential trend of the water-leaving
reflectance with lake depth. The values of the attenuation factor obtained
from in-situ data are 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. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|