Vegetation Effects on Passive Microwave Measurements

The developed laboratory waveguide transmission system for measuring the attenuation of microwaves by vegetation canopies is discussed. Some results obtained for the attenuation effects by fragments of trees in the frequency band 0.8 -10.0 GHz are presented. The waveguide transmission system and the measuring procedure provide the acquiring of continuous attenuation spectra in a wide frequency band under controlled vegetation parameters. The propagation characteristics of the electromagnetic waves in the ultra-wide band waveguide transmission system are similar to the propagation characteristics in the free space. This makes possible to use the laboratory results in practice.