Measurements of Foliage-Induced Signal Modulation at L-Band

The use of imaging radar to detect targets concealed under foliage remains an active area of research. While it is widely known that lower frequencies are better at penetrating vegetation, various effects contribute to the overall difficulty of FOPEN target detection. Among these is the inhomogeneous nature of a foliage canopy, which introduces fluctuations in signal amplitude and phase across a synthetic aperture, potentially causing azimuthal defocussing of images of targets. Measurements of such foliage-induced modulations are thus helpful in understanding this effect. This paper presents results from such measurements made at L-band using the Ingara airborne SAR as transmitter in conjunction with a ground-based fully-polarimetric receiver.