A new empirical model to retrieve soil moisture and roughness from C-band radar data
Sano, E. E., Moran, M. S., Huete, A. R. and Miura, T.
2003 Remote Sensing of Environment, 84(1): 42-52
Sano, E. E., Moran, M. S., Huete, A. R. and Miura, T., (2003), "A new empirical model to retrieve soil moisture and roughness from C-band radar data", Remote Sensing of Environment, 84(1): 42-52.
Abstract:
A sensitivity analysis of C-band (5.3 GHz) and Ku-band (14.85 GHz) synthetic aperture radar (SAR) data to the bare soil moisture content of agricultural fields was conducted in this study. The C-band data were obtained with a 23กใ incidence angle, whereas the Ku-band data were obtained with 35กใ, 55กใ, and 75กใ incidence angles. The fields presented either a small-scale or an intermediate-scale periodic soil roughness components, associated with level-basin and furrow irrigation systems, respectively. For fields with a small-scale roughness component, the SAR data were sensitive to soil moisture, particularly at the C-band with a 23กใ incidence angle and Ku-band with a 35กใ incidence angle. For fields with a intermediate-scale roughness component, both C- and Ku-band data were nearly insensitive to soil moisture. By using a theoretical surface scattering model, this study also analyzed the effects of different soil roughness components [root mean square (RMS) height h, correlation length, and periodic row structure] in the SAR data. For fields with RMS height <0.3 cm, a small variation in h (from 0.1 to 0.3 cm) provoked a significant variation in the SAR data (up to 8 dB).
