2021, 43(1):21-29.
Abstract:
In wideband radar, the echoes backscattered from a target undergoes translation and dilation. The wideband ambiguity function is a common approach to analyze this type of echoes and estimate the translation and dilation parameters. However, this approach has high computational complexity and poor real-time capability. Moreover, this approach does not work well in the case of extended targets due to low precision. The Mellin matched filter is a transform-domain matched filter, which is based on the Mellin transform. Although this filter can estimate the scaling parameter effectively, the estimation accuracy is very sensitive to the time delay of the target. To overcome this drawback, a modified Mellin matched filter is proposed, which exploits the amplitude spectrum of the transmitted signal to construct the filter impulse response function. In this paper, the scaling factor is estimated by the proposed filter, and then a time-delay matched waveform dictionary is constructed with the estimated scaling to further estimated time delay. Simulation results suggest that the parameter estimation accuracy of the proposed filter is more precise than those of the Mellin matched filter and the wideband ambiguity function. In addition, the parameters of extended targets can be efficiently estimated by the proposed filter.
