High precision coherent compensation for multiband radar data at low SNR

Coherent compensation among subbands is the first problem to be solved in multi-band radar data fusion,which is directly related to the success of the multi-band data fusion.At present,there are two popular methods,one is based on the data correlation,and the other is based on the Prony model.Both of them can achieve satisfactory results at high signal to noise ratio(SNR),but not applicable in high clusters.This paper analyzes the impact of fixed phase and linear phase which caused the coherent phase mismatch on high radar range profile(HRRP),then proposes a highly accurate phase parameter estimation method according to the entropy-minimization principle and nonlinear least-squares fit.Simulation results show that the method proposed can get a higher phase estimation accuracy in low SNR conditions.