Wt. Crow et al., An observation system simulation experiment for the impact of land surfaceheterogeneity on AMSR-E soil moisture retrieval, IEEE GEOSCI, 39(8), 2001, pp. 1622-1631
Citations number
36
Categorie Soggetti
Eletrical & Eletronics Engineeing
Journal title
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
Using a high-resolution hydrologic model, a land surface microwave emission
model (LSMEM), and an explicit simulation of the orbital and scanning char
acteristics for the advanced microwave sensing radiometer (AMSR-E), an obse
rving system simulation experiment (OSSE) is carried out to assess the impa
ct of land surface heterogeneity on large-scale retrieval and validation of
soil moisture products over the U.S. Southern Great Plains using the 6.925
GHz channel on the AMSR-E sensor. Land surface heterogeneity impacts soil
moisture products through the presence of nonlinearities in processes repre
sented by the LSMEM, as well as the fundamental inconsistency in spatial sc
ale between gridded soil moisture imagery derived from in situ point-scale
sampling, numerical modeling, and microwave remote sensing sources. Results
within the 575 000 km(2) Red-Arkansas River basin show that, for surfaces
with vegetation water contents below 0.75 kg/m(2), these two scale effects
induce root mean squared errors (RMSEs) of 1.7% volumetric (0.017 cm(water)
(3)/cm(soil)(3)) into daily 60 km AMSR-E soil moisture products and RMS dif
ferences of 3.0% (0.030 cm(water)(3)/cm(soil)(3)) into 60 km comparisons of
AMSR-E soil moisture products and in situ field-scale measurements of soil
moisture sampled on a fixed 25-km grid.