Detecting management practices of improved grasslands using ERS-1 SAR data.

Abstract

Abstract:The backscattering behavior of the improved grasslands is investigated with the ERS-1 SAR (C-band with VV polarization, 23 degrees incident angle) data of a dairy farming area in Japan. Capabilities of ERS-1 SAR data to detect two major management procedures, which are grass renovation and grass mowing, are discussed using a field based interpretation approach. Our results show that renovated grasslands with high surface roughness and high soil moisture content have extremely high backscattering coefficients, whereas the others do not show such high coefficients. The SAR-derived grass renovation map using backscattering signatures is almost consistent with the results from Landsat TM data. However, mown grasslands show a backscattering signature that is similar to those of unmown grasslands. Detection of grass mowing practices is still difficult using ERS-1 SAR data alone.Grass renovation is a very important procedure for improving grasslands productivity. In dairy farming areas where optical data often hindered, the success in monitoring grass renovation using ERS-1 SAR data is considered to be very useful.