1. A method of processing a radar signal for classifying a target, comprising: detecting and tracking a target in range using successive range-Doppler maps; creating a spectrogram by concatenating all Doppler cells at each tracked target range value; forming conditional probabilities using, as a vector, the features range, absolute value of velocity, amplitude, and spectral width of the spectrogram, wherein forming conditional probabilities of the spectrogram comprises using a distribution function formed by training vectors based on the features range, absolute value of velocity, amplitude, and the spectral width of the spectrogram; and making a classification decision with respect to the at least one target based upon a comparison of the conditional probability to a total probability, wherein the spectral width of the spectrogram is computed by computing total power across each row in a spectrogram buffer that includes a current slice and the previous slices for the target, incrementing a counter each time the total power of a bin is above a threshold, wherein the counter is the spectral width of the spectrogram.