Submitted to: Rivista Italiana di Telerilevamento
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/1/2005
Publication Date: 6/1/2005
Citation: Jackson, T.J., Hurkmans, R., Hsu, A., Cosh, M. 2005. Soil moisture algorithm validation using data from the Advanced Microwave Scanning Radiometer (AMSR-E) in Mongolia. Italian Journal of Remote Sensing. 30(31):23-32.
Interpretive Summary: A soil moisture mapping technique based on satellite microwave remote sensing was evaluated using data from a study site in Mongolia. For the first time efforts are underway to use satellite measurements to estimate and map global soil moisture. This is a result of the availability of new satellite-based low frequency microwave radiometers and in particular the Advance Microwave Scanning Radiometer instrument supplied by Japan and flying on the NASA Aqua satellite. As part of its algorithm selection process, Japan has been evaluating alternative soil moisture algorithm approaches including a single channel method. Overall the retrieval algorithm produced acceptable results for soil moisture and temperature. It was necessary to use a modified vegetation index in the estimation of the vegetation water content due to the unusual soil and surface properties in the test site. It is well known that vegetation has a significant effect on the ability to retrieve soil moisture. The conditions in Mongolia were relatively benign for the expected capabilities of AMSR, very low levels of vegetation. More challenging sites will be considered in the future along with more robust data sets. Both the NASA and Japan are committed to providing a soil moisture product from the satellite data. These results will contribute to the algorithm selection and the eventually applications in hydrology and agriculture.
Technical Abstract: New satellite-based low frequency microwave radiometers are being evaluated for estimating soil moisture. These include the Advance Microwave Scanning Radiometer (AMSR) instruments on the NASA Aqua satellite and the Advanced Earth Observing Satellite (ADEOS-II). Although there have been satellite instruments in space previously with these frequencies, the AMSR programs include the first ever commitments to providing a soil moisture product. As part of its algorithm selection process, the Japanese Aerospace Exploration Agency (JAXA) has been evaluating four different soil moisture algorithm approaches including a single channel method. This algorithm was evaluated here using validation data collected in Mongolia. Data quality issues, approaches to validation and algorithm performance are analyzed and discussed. Overall, the algorithm performed as expected based upon previous research.