Analysis of Forest Radar Backscatter Using Airborne Polarimetric Data and Multi-Temporal Ers-1 Sar Data

In August 1989 the NASNJPL multiband (P,L,C) polarimetric SAR acquired data over the FlevolandNeluwe test site in The Netherlands. During the commissioning phase of ERS-1 this test area has been observed every three days by the SAR. Trees, as opposed to agricultural crops, exhibit some characteristic polarimetric backscattering properties. These may be caused by the branch structure and branch orientation as well as by the trunk -ground interaction. Empirical relations between polarimetric data and forest characteristics, covering a wide range of species, will be presented in a systematic way. These include results of polarimetric classification of forest stands using maximum contrasts, classification of scattering behaviour, degree of polarization, the HH-VV phase difference and relations between radar backscatter properties and forest biomass and forest soil moisture content. A simulation of the temporal behaviour of ERSl SAR backscatter for a poplar stand will be discussed.