Analysis of Polarization Mismatch Loss for Horizontal Linear Feature Detection.

摘要

FOR most airborne radar, target detection is possible when the receiver collects target energy in excess of ground clutter and channel noise. Ground clutter is the predominant impediment to successful detection, and is minimized by varying the grazing angle. Extensive literature exists on backscattering statistics for various terrain types. However, little research exists on the significance of aspect angle and its relationship to polarization mismatch loss. Research has been conducted investigating linear feature detection in synthetic aperture radar imagery. Furthermore, general research exploring the phenomena encountered by communications systems when varying polarizations has also been conducted. F Polarization mismatch loss occurs because most imaging geometries have limited aspect to target. This causes the antenna s slant plane to align poorly with the target linear feature, and results in a portion of the transmit signal reflecting at an orthogonal polarization. The polarization mismatch loss is in addition to the (two-way) antenna loss that occurs at target angles off the antenna boresight. By analyzing the polarization mismatch as a function of both aspect and grazing angles, we can numerically evaluate the expected loss as they relate to horizontal linear feature detection.