HR: 0800h
AN: H31D-0633    [Abstracts]
TI: Assessment of Potential AMSR-E Soil Moisture Disaggregation Using Scatterometer Observations
AU: Lakshmi, V
EM: Lakshmi@mailbox.sc.edu
AF: USC Department of Geological Sciences, 701 Sumter St, Columbia, SC 29208, United States
AU: * Mladenova, I E
EM: maldenoi@mailbox.sc.edu
AF: USC Department of Geological Sciences, 701 Sumter St, Columbia, SC 29208, United States
AU: Jackson, T
EM: Tom.Jackson@ars.usda.gov
AF: USDA Hydrology and Remote Sensing Laboratory, Bldg 007 BARC-West, Beltsville, MD 20705, United States
AU: Long, D
EM: long@ee.byu.edu
AF: BYU Centre for Remote Sensing, Electrical and Computer Engineering Department, 459 Clyde Build, Provo, UT 84602, United States
AB: Advanced Microwave Scanning Radiometer (AMSR-E) on the NASA's Aqua platform has been providing land surface variables such as soil moisture in near real-time since 2002. A fundamental ongoing issue with the satellite estimates, as with any satellite passive microwave sensor, is their coarse spatial scale and how to downscale them to spatial resolutions compatible with a wider range of applications. Disaggregation techniques based on a synergism between passive and active microwave observations have shown promising results. However the available radar systems have limited temporal and spatial coverage in the mid-latitudes where soil moisture is important. Most of the disaggregation methodologies are based on temporal change detection in soil moisture. Another alternative is the QuikSCAT scatterometer, which offers daily observations with a 2.225km ground pixel size for the enhanced backscattering coefficient product. This may be a desirable option that offers a long-term data set with high temporal resolution for developing downscaling technique for disaggregation of radiometer derived soil moisture estimates (i.e. AMSR-E). QuikSCAT backscatter sensitivity to soil moisture was studied over the National Airborne Field Experiment 2006 (NAFE"06) area located in the south-eastern part of Australia. The domain encompasses a wide range of ground conditions including flood irrigation. Point comparisons between QuikSCAT backscattering coefficients and AMSR-E soil moisture revealed the greatest sensitivity of QuikSCAT backscatter to soil moisture over the Kyeamba study area, which was mostly grazing land. North-south and east-west oriented transect lines for a variety soil moisture conditions were also examined. Overall, the QuikSCAT backscatter and AMSR-E soil moisture show similar trends. However the larger variability of the backscatter values was evident in more of the transect lines. As a result, further analysis of the impact of NDVI and vegetation type is needed. The proposed assimilation of radiometer and scatterometer obtained observations will result into high temporal and fine spatial resolution soil moisture product. Aquarius, due for launch in 2009, carries on board both instruments. On that way exploring the possibility of combining AMSR-E and QuikSCAT observations can be beneficial for Aquarius by building more knowledge on the soil moisture temporal and spatial variability and by improving the available soil moisture and disaggregation algorithms.
DE: 1640 Remote sensing (1855)
DE: 1855 Remote sensing (1640)
DE: 1866 Soil moisture
SC: Hydrology [H]
MN: 2007 Fall Meeting