RELATING FOREST BIOMASS TO SAR DATA

This paper presents the results of an experiment defined to demonstrate the use of radar to retrieve forest biomass. The SAR data were acquired by the NASA/JPL SAR over the Landes pine forest during the 1989 MAESTRO-1 campaign. The SAR data, after calibration, have been analyzed together with ground data collected on forest stands from young stage (8 yrs) to mature stage (46 yrs). The dynamic range of the radar backscatter intensity from forest was found maximum at P-band and decreases with increasing frequencies. Also, cross-polarized backscatter intensity yields the best sensitivities to variations of forest biomass. L-band data confirmed past results on good correlation with forest parameters. The most striking observation has been the strong correlation of P-band backscatter intensity to forest biomass. In order to develop algorithms to infer forest biomass from spaceborne SAR's, the experimental results will be compared with observations on other forest ecosystems and will be interpreted by theoretical modeling.