Radar measurement of forested areas during OTTER

Abstract To test a forest ecosystem model in the Oregon Transect Ecosystem Research (OTTER) project, it is desirable to find forest canopy parameters via radar remote sensing measurements. Conventionally, forest biomass, along with quantities such as the leaf area index, drives the model. However, it is shown from the SAR data collected over the OTTER sites that the backscatter is not uniquely related to biomass. A sensitivity study is carried out using a scattering model to determine the variation of radar cross section as a function of several forest parameters. The results verify the above observation, and lead to the selection of suitable quantities to be recovered via radar experiments. Since this forest scattering model cannot be easily used for inversion of unknown parameters, the use of simplified models in forest parameter estimation schemes is suggested.

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