MEASUREMENTS OF RADAR BACKSCATTER FROM AN ARTIFICIAL TREE - AN INDICATION OF AZIMUTHAL VARIATIONS AND POLARIZATION SENSITIVITY OF TREES

Measurements of radar backscatter from an artificial tree were made in the laboratory at 6 and 10 GHz at horizontal incidence. The system had a resolution cylinder 18 cm in diameter and 11 cm long, so about half of the tree (30.5 cm high) was within the beam. The mean returned power from the target with leaves was always higher than that from the target without leaves, as expected. The signal faded with an exponential distribution when the artificial tree was rotated about its trunk, with no angular trend apparent. When the leaves were present, tilted polarizations gave results favouring an angle corresponding with that of the branches. When leaves were absent, the trunk of the tree dominated the radar backscatter at all polarizations.