“NASA Takes Earth’s Vital Signs by Satellite,” by Mary Ann Capehart, in the Spring 2015 issue Arizona Water Resource, from the Arizona Water Resources Research Center in Tucson, described four earth-observing satellite programs operated by the National Aeronautic and Space Administration (NASA).
The four programs are the following:
1) Gravity Recovery and Space Experiment (GRACE), begun in 2002, measures changes in Earths’ gravitational pull from place to place, which measurements can be used to track water movements;
2) the Landsat series, launched in 1972, is a joint mission of NASA and the U.S. Geological Survey (USGS) to collect continuous images and reflected-energy measurements;
3) Soil Moisture Active Passive project (SMAP), started in January 2015, uses satellite images and ground sensors to map water in the first few inches of soil, allowing, for example, farmers to target irrigation; and
4) Global Precipitation Measurement project (GPM), started in February 2014, is a joint project between NASA and its counterpart agency in Japan to ccordinate precipitation measurements from 12 satellites.
A related article from Texas is “Satellites, Sensors and Soil,” by Sara Carney, in the Summer 2015 issue of Texas H2O, from the Texas Water Resources Institute at Texas A&M University; available online at http://twri.tamu.edu/txh2o.
More information about NASA’s earth-observing programs is available online at http://eospso.nasa.gov/.