Application of LS-SVM to the Retrieval of Bare-Surface Soil Moisture from Simulated Active and Passive Microwave data

In this letter the application of the Least Squares Support Vector Machines (LS-SVM) to soil moisture inversion based on active and passive microwave data is explored. The integral equation model (IEM) is chosen to obtain the backscattering coefficients which serve as the active microwave data for simulation. Similarly, the emissivity model is applied to perform simulations under a large range of soil moisture and surface roughness conditions in order to acquire the brightness temperature and generate the datasets. The frequencies of interest include 1.4 GHz (L-band), 6.9 GHz (C-band) as well as 10.7 GHz (X-band). The effectiveness of this application is assessed by implementing various input combinations (i.e. different microwave sensor frequencies, polarization status and incident angles). This study demonstrates the great potential of LS-SVM in the inversion of soil moisture based on microwave remotely sensed data.