Adaptive Altitude Measurement Based on Digital Elevation Model in VHF Array Radar

The multi-path signal and the direct signal, lying within a beam-width of the receiving antenna, are highly correlated, which cause badly effect to the performance of low-angle altitude measurement for very high frequency (VHF) radar. A novel adaptive altitude measurement is proposed. Combine digital elevation model (DEM) with distributed sources model, a multipath signal model was constructed which is much closer to the practical rough reflection surface. The height of target was obtained through multi-dimension alternating projection and synthesized vector maximum likelihood algorithm. Simulation results and the measured data processing demonstrate the validity and feasibility of the proposed method.