Terrain compensation for OTHR receive array

The performance of an OTHR array situated on irregular terrain is presented, and the compensation of the effects of terrain irregularities is illustrated. The model used evaluates the effects of long correlation intervals on the received pattern by taking into account both the vertical terrain deformation and the effects of local ground tilt on the element pattern. A typical no-error pattern exhibits a -40 dB Taylor weighted sidelobe structure. Without beamformer compensation for terrain irregularities, the sidelobe performance is degraded to the -25 dB level. Using a beamformer compensation optimized for 10/spl deg/ elevation at azimuth boresight, the sidelobe performance is nearly fully recovered. The results obtained are very promising, and suggest that future OTH receive antenna ground preparation costs can be significantly reduced.<>