Weak target detection based on fractional spectral subtraction in sea clutter

A method based on fractional spectral subtraction (FRSS) to detect weak targets in sea clutter is proposed. The method applies FRFT (fractional Fourier transform) to detection cell and reference cell of echo signal respectively, the fractional clutter spectrum resulted from which is then subtracted from the fractional signal-clutter spectrum, to enhance the signal amplitude and restrain the clutter. The experiment using the IPIX measured data shows that the method proposed in this paper has obvious advantages than only applying FRFT to echo in increasing the difference between the FRFT peak values of target and clutter as well as enhancing the SCR When the SCR is reduced to -10, the method can still detect targets easily.