G-REALM: Investigating datum translations for integration of altimeter-derived operational water level products with in situ lake and reservoir gauge data.

Charon Birkett (University of Maryland, United States)


OBrien Kate (UMD, USA); Brian Beckley (SGT, USA); Ricko Martina (SGT, USA); Holmes Simon (SGT, USA); Yang Hunter (SGT, USA)

Event: 2015 Ocean Surface Topography Science Team Meeting

Session: Others (poster only)

Presentation type: Type Poster

G-REALM is a NASA/USDA funded operational program offering water-level products for lakes and reservoirs as derived from the NASA/CNES and ESA/ISRO/CNES radar altimeter missions. The main stakeholder is the USDA/FAS though many other end-users utilize the products for a variety of interdisciplinary science and operational programs. While USDA analysts require relative lake level variations, there is a demand for products based on orthometric datums to more easily integrate the altimeter results into time series of archival (and often sporadic) gauge-based measurements. A recent G-REALM 10-day resolution product upgrade and expansion has allowed for more accurate lake level products and for a greater number of water bodies. The upgrade also introduces datum translation factors that enable the satellite measurements to be converted to WGS84 and various Geoid reference frames. Here, we discuss both the upgrade and the translation factors, assessing their accuracy via comparison with in situ data from around the world.

Poster show times:

RoomStart DateEnd Date
Grand Ballroom Foyer Thu, Oct 22 2015,11:00 Thu, Oct 22 2015,18:00
Charon Birkett
University of Maryland
United States