Radial velocity and range bias estimation using composite hyperbolic frequency-modulated signals

To measure the radial velocity of moving targets in active sonar, a method of radial velocity and range bias estimation using composite hyperbolic frequency-modulated (HFM) signals is proposed. Doppler-invariant property and target ranging bias principles of HFM signals in real domain are analyzed, the realization expression of target radial velocity estimate and range bias removal with composite HFM signals is given, and the error characteristics of target radial velocity measurement under the background of multi-bright spot intensity fluctuation of target echo are studied. The measurement accuracy of the target radial velocity can be improved through the selection of the signal composite forms, the signal bandwidth and the correlation processing of the echo intensity waveform. Numerical simulation and sea trial data analysis results show that the proposed method can accurately measure the radial velocity of target in a single frame and correct the target ranging bias, which effectively supports the judgment of moving target.