The synergistic use of microwave coarse-scale measurements and two adopted high-resolution indices driven from long-term T-V scatter plot for fine-scale soil moisture estimation

In an attempt to retrieve soil moisture content (SMC) from remote sensing techniques, this article suggests and evaluates a developed approach that overcomes three of the most fundamental limitations temperature–vegetation (T-V) scatter plot method are (1) low accuracy T-V in cases corresponding its wet dry edges not formed appropriately, (2) incompatibility index maps different days, (3) inability obtain absolute SMC values indices. The research consists main steps. first step, measurements eight global situ networks were applied select appropriate accurate microwave mission among Advanced Microwave Scanning Radiometer 2, Soil Moisture Ocean Salinity, Active Passive. results outlined superiority SMAP’s products terms RMSE correlation coefficient (root mean square difference (RMSE) = 0.3–0.12 m3/m3 R 0.53–0.93). At second 1-year was then, two adopted indices, namely annual (ASMIHR) daily (DSMIHR), extracted. ASMIHR driven novel concept called “co-moisture line” introduced DSMIHR. third step proposed method, Disaggregation based on Physical Theoretical scale Change as downscaling algorithm with novelty identify parameter partial derivative data relative indices using relationship between coarse-scale SMAP pixels. Across four pixels located study area, obtained average 0.7. This followed by integrating DSMIHR provide at intermediate spatial resolution. evaluated agricultural site Passive Validation Experiment 2016-Manitoba. ultimate proved promising consistency field (R 0.66 no-bias 0.06 m3/m3).