CoAuthors

Martina Ricko (KBR at NASA/GSFC, USA); Xu Yang (KBR at NASA/GSFC, USA); Wei Hao (GST at NOAA/NESDIS/STAR, USA); Ce Yi (SSAI at NASA/GSFC, USA)

The Global Water Monitor is a NASA funded operational program offering water-related products for lakes, reservoirs, river reaches, and wetland zones. These are currently being derived from the 10-day and monthly-resolution radar altimeter series. However, observational parameters from the laser-based ICESat-2 mission, and the enhanced SWOT KaRIn instrument will also be integrated to meet various end user requirements. The resulting measurements will ultimately be a combination of surface water level and slope, surface water extent, water storage and basin bathymetry, plus a suite of Status Indicators which highlight deviations from long-term and seasonal averages. The main stakeholders are the USDA/Foreign Agricultural Service, the US Geological Survey, USACE/NGA, and various Wetland-related organizations. Applications centre on water and energy resources and fish-catch potential, and on natural hazards (floods and droughts). There is a demand for a global monitoring service, but primary focus is on regions where insitu (gauge) measurement access is restricted or delayed, or where gauge deployment is hazardous.
Ongoing surface acquisition checks and feedback to CNES focusses on the success or failure of the on-board DEM’s on a case-by-case or regional basis. Multiple projects are also underway to improve the surface elevations measurements and the along track resolution (minimum water body width) via exploration of the high resolution (Doppler) Range estimates, the FF-SAR technique, and the high- resolution radiometer-based wet tropospheric correction. And while Level3+4 surface water products are being directed by end user requirements, the overriding NASA objectives are the formation of high-quality Earth Data Records with high accuracy and uniformity across multiple decades.