Near-Field Measurement Study for Over-the-Horizon Radar Transmit Beamformers

Two error types related to near-field measurements in over-the-horizon radar transmit beamformers are studied. The first concerns the use of measured array manifolds for beamformer calibration purposes and the second concerns performance verification using the measured beamformer output gain pattern. It is determined through theoretical analysis that important clutter rejection and performance verification accurary degradations will occur if measurements are performed at practical distances including 500 meters.