Water levels in Danish lakes observed by CryoSat, SARAL/AltiKa, and Envisat

Karina Nielsen (DTU Space, Denmark)

CoAuthors

Lars Stenseng (DTU Space, Denmark); Ole Andersen (DTU Space, Denmark); Heidi Villadsen (DTU Space, Denmark); Per Knudsen (DTU Space, Denmark)

Event: 2014 Ocean Surface Topography Science Team Meeting

Session: Science Results from Satellite Altimetry: Inland waters (multi-mission and long-term monitoring)

Presentation type: Type Oral

Within the last five year period new types of satellite altimetry missions have been launched e.g. CryoSat and SARAL/AltiKa. The ESA satellite Cryosat-2, launched in 2010, is the first mission that carries a radar altimeter, which is able to operate in Synthetic aperture radar (SAR) mode. Compared to conventional altimetry, the SAR mode provides a much higher resolution in the along-track direction, which for Cryosat-2 is approximately 300 m. The Indian and French mission SARAL/AltiKa, launched in 2013, is the first satellite that carries a Ka band altimeter. The main advantage of the high frequency Ka band is the greater accuracy.
These new missions opens new possibilities with respect to monitoring and modeling of inland water bodies, since much smaller bodies can be observed than previously.

In this study, which is part of the FP7 project Land and Ocean take up from Sentinel-3 (LOTUS), we compare the performance of the missions CryoSat, Envisat and SARAL/AltiKa over selected Danish lakes ranging from a few km^2 to ~50 km^2 in size. We compare the along-track stability of the estimated water levels within the lakes, the seasonal signal, and the absolute mean water levels of the lakes. To validate the altimetry based water levels we compare these with independent data such as highly accurate laser measurements and in-situ water level measurements.
 

Oral presentation show times:

RoomStart DateEnd Date
Red salon Tue, Oct 28 2014,14:00 Tue, Oct 28 2014,14:15
Karina Nielsen
DTU Space
Denmark
karni@space.dtu.dk