Advanced Models for Clutter
Interim rept. Jan 1989-Feb 1990
VIRGINIA POLYTECHNIC INST AND STATE UNIV BLACKSBURG DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
Pagination or Media Count:
This report summarizes three important results obtained during the reporting period. First, it is shown that the Luneberg-Kline asymptotic series for the current induced on a conducting rough surface always produces an error in the shadow zone. That is, the L-K series yields zero net current in the shadow zone for all terms in the asymptotic series. This shortcoming limits the usefulness of the L-K series for recovering diffraction effects. The method of smoothing is used to determine the fluctuating component of the field scattered by a randomly positioned collection of discrete scatterers to the level of the distorted wave Born approximation. Of particular importance here is the role of the coherent or average field in the medium as a source for the fluctuating field. Finally, it is shown how to go about developing an improved high frequency approximation for scattering from rough surfaces. In particular, it is shown that the shadowed Kirchhoff approximation should comprise the iterate in the basic integral equation for the current because it contains an infinite resummation of all of the shadowing effects.
- Active and Passive Radar Detection and Equipment
- Radiofrequency Wave Propagation