Calibration of the Integral Equation Model for SAR data in C‐band and HH and VV polarizations

Abstract

The inversion of radar images to estimate surface soil parameters requires the use of well‐calibrated backscattering models. The first objective of this paper is to confirm the empirical calibration proposed by Baghdadi et al. (2004 Baghdadi, N., Gherboudj, I., Zribi, M., Sahebi, M., Bonn, F. and King, C. 2004. Semi‐empirical calibration of the IEM backscattering model using radar images and moisture and roughness field measurements.. International Journal of Remote Sensing, 25: 3593–3623. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]) for the backscattering Integral Equation Model (IEM). That calibration was a partial one, because it covered only a few radar configurations. The second objective is to extend this calibration to include Synthetic Aperture Radar (SAR) data in C‐band, for HH and VV polarizations, at any radar incidence between 20° and 50°. Advanced Synthetic Aperture Radar (ASAR) data were used to supplement the database employed by Baghdadi et al. (2004 Baghdadi, N., Gherboudj, I., Zribi, M., Sahebi, M., Bonn, F. and King, C. 2004. Semi‐empirical calibration of the IEM backscattering model using radar images and moisture and roughness field measurements.. International Journal of Remote Sensing, 25: 3593–3623. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]). The results show good agreement between the backscattering coefficients given by the SAR sensors and those estimated from the calibrated IEM. This study also confirms the robustness of this calibration.