A new constant false alarm rate technique

A new method for achieving a constant false alarm rate (CFAR) in a radar receiver is proposed which is based on transforming the unknown probability density function of the input clutter to a uniform distribution and setting the Pfa after the transformation. The constants required for the transformation are obtained by a simple least squares curve fitting method. With about 10,000 samples, the technique is shown to give very good results for Rayleigh and Weibull clutter and reasonably good values for log-normal clutter. The method is quite general and can be applied to any distribution of the interfering signal.