Ray and Fares Publish Results on Evaluating NASA and European Space Agency’s Satellite Products in Texas

July 3, 2017

CARC Research Scientists Ram Ray and Ali Fares, in collaboration with two other scientists, just published the results of their study on evaluating four major remote sensing soil moisture (SM) products over the state of Texas. The Advanced Microwave Scanning Radiometer—Earth Observing System (AMSR-E, 2002-2011); (AMSR2, 2012–present); and the Soil Moisture Active Passive system (SMAP, 2015–present) are NASA products and the fourth one, the Soil Moisture Ocean Salinity system, is a product of the European Space Agency.

They compared each satellite SM product to situ soil moisture measurements and also conducted an inter-comparison of the four satellite SM products at 15 different locations in Texas over six major land cover types (cropland, shrub, grassland, forest, pasture and developed) and eight climate zones along with in situ SM data from 15 Mesonet, USCRN and USDA-NRCS Scan stations.

Results show that SM data from SMAP had the best correlation with in situ measurements among the four tested satellite surface SM products. Despite the coarser spatial resolution of all four satellite products (25–36 km), their SM measurements are considered reasonable and can be effectively used for different applications, e.g., crop water update and potential yield, flood forecasting, drought and fire prediction. The authors added that further evaluation of each satellite product is recommended prior to its use in practical applications. Their work is continuing on using these soil moisture data to determine different water cycle components.

This article was published as open source so that it can be downloaded free of charge to achieve wide outreach: http://www.mdpi.com/2073-4441/9/6/372

Figure: Map of the state of Texas, the study site of this project, depicting the different climate regions, and selected in situ stations in the state.

Dr. Ali Fares


Ali Fares, Ph.D.
Interim Associate Director, Cooperative Agricultural Research Center
(936) 261-5019




Ram L. Ray Ph.D.
Research Scientist
(936) 261-5094