From repeat pass SIR-C L band polarimetric SAR interferometric data and fully maximum likelihood inversion decomposition model of PolInSAR

a method for sub-canopy soil moisture estimation using repeat pass SIR-C PolInSAR data is proposed.At the same time

the potential and validity of fully maximum likelihood inversion decomposition model of PolInSAR for sub-canopy soil moisture inversion is investigated.Firstly

from the random oriented volume over ground two layer coherent scattering model and the statistical characteristics of Pol-InSAR coherency matrix

the fully maximum likelihood inversion de-composition model is used to reconstruct or recover the surface polarimetric coherency matrix with volume scattering compo-nents significantly removed;then

from recovered surface polarimetric coherency matrix

co-HH

VV and cross-HV polarization backscattering coefficient are obtained

and the sub-canopy soil moisture are inverted from Oh and Dihedral scattering model.At last

Compared the inversion result with the field measurement and the climate data of hetan region from 1951 to 2006

the pre-liminary result indicates that the proposed method based on fully maximum likelihood inversion decomposition model has enough high inversion accuracy

if the new spaceborne or airborne polarimetric SAR interferometric data with synchronously spaceborne or airborne-ground measurement will be acquired

the validity and accuracy of proposed inversion method will be further investigated and validated.