“…The physical features include the location and magnitude of peak, the scattering center location, the intensity magnitude, the profile, the perimeter and area of the target, the shape, the micro-motion characteristics, etc. The transform domain features mean the features obtained by Fourier Transform [15], [16], Wavelet Transform [17], [18], Non-negative Matrix Factorization [19], [20], Radon Transform [21], or Sparse Representation [22], [23], etc. Then, these features are classified by K-nearest Neighbor Classifier [24], Bayesian Classifier [25], AdaBoosting Classifier [26], [27], Support Vector Machine (SVM) [28], or Hidden Markov Model [29], etc.…”