Target feature extraction of frequency domain data with optimal rational approximation

An approach to target feature extraction of frequency domain data with optimal rational approximation is presented. The full response in the frequency domain is taken into account. The function approximation theory and numerical method are used to find the feature coefficients of the target which are equivalent to the poles of the target. The feature coefficients obtained are invariant to the radar aspect angles. Numerical results show that the method is robust to noise. The method possesses the capability of determining the degree of the rational function. When the degree is incorrect, the feature coefficients obtained are quite sensitive to the aspect angles; otherwise, they are insensitive.<>