@article{PAR00006112, title = {{A}n improved algorithm for disaggregating microwave-derived soil moisture based on red, near-infrared and thermal-infrared data}, author = {{M}erlin, {O}. and {A}l {B}itar, {A}. and {W}alker, {J}. {P}. and {K}err, {Y}ann}, editor = {}, language = {{ENG}}, abstract = {{A}ccurate high-resolution soil moisture data are needed for a range of agricultural and hydrologic activities. {T}o improve the spatial resolution of similar to 40 km resolution passive microwave-derived soil moisture, a methodology based on 1 km resolution {MODIS} ({MOD}erate resolution {I}maging {S}pectroradiometer) red, near-infrared and thermal-infrared data has been implemented at 4 km resolution. {T}he three components of that method are (i) fractional vegetation cover, (ii) soil evaporative efficiency (defined as the ratio of actual to potential evaporation) and (iii) a downscaling relationship. {I}n this paper, 36 different disaggregation algorithms are built from 3 fractional vegetation cover formulations, 3 soil evaporative efficiency models, and 4 downscaling relationships. {A}ll algorithms differ with regard to the representation of the nonlinear relationship between microwave-derived soil moisture and optical-derived soil evaporative efficiency. {A}irborne {L}-band data collected over an {A}ustralian agricultural area are used to both generate similar to 40 km resolution microwave pixels and verify disaggregation results at 4 km resolution. {A}mong the 36 disaggregation algorithms, one is identified as being more robust (insensitive to soil, vegetation and atmospheric variables) than the others with a mean slope between {MODIS}-disaggregated and {L}-band derived soil moisture of 0.94. {T}he robustness of that algorithm is notably assessed by comparing the disaggregation results obtained using composited (averaged) {T}erra and {A}qua {MODIS} data, and using data from {T}erra and {A}qua separately. {T}he error on disaggregated soil moisture is systematically reduced by compositing daily {T}erra and {A}qua data with an error of 0.012 vol./vol.}, keywords = {{D}isaggregation ; {D}ownscaling ; {S}oil moisture ; {E}vaporation ; {N}onlinear ; {SMOS} ; {NAFE} ; {MODIS}}, booktitle = {}, journal = {{R}emote {S}ensing of {E}nvironment}, volume = {114}, numero = {10}, pages = {2305--2316}, ISSN = {0034-4257}, year = {2010}, DOI = {10.1016/j.rse.2010.05.007}, URL = {https://www.documentation.ird.fr/hor/{PAR}00006112}, }