Altitude Measurement Based on Terrain Matching in VHF Array Radar

摘要

The multipath signal and direct signal lying within a beamwidth of a receiving antenna are highly correlated, which degrades the performance of D0A in a VHF array radar. Especially on rough terrain, the reflection centers of elements are not at the same horizontal plane; thus the variation of indirect wave path difference from each element with respect to the target's depression angle is not linear. In this paper, we assume the two-path-component data model, with one direct component and one indirect component related to the ground reflection. This paper builds a highly deterministic multipath signal model which takes the curvature of the signal path and the terrain parameters of the reflection region into account based on the sphere model, gives calculation methods of the reflection coefficient and lengths of the direct path and indirect path, and proposes a synthetic steering vector super-resolution algorithm. The results for both simulated and measured data show that this method provides excellent performance in resolving the DOA problem in a multipath environment compared to the data model that only considers the flat-earth model.