“…There are many radar signatures which can be used for radar target recognition: Natural frequencies of radar target [159][160][161][162][163][164][165][166], high resolution range (HRR) profiles [72,[75][76][77][78][79][80] of radar target, microwave image of the radar target [1,26,31,50,55,70,73,[81][82][83][84][85][86][87][88][89][90][91][92][93][94][95][96][97][98][99][100], and inverse synthetic aperture radar (ISAR) [55, 86-100, 125, 126] image proved to be useful features for target recognition. Jet engine modulation and helicopter modulation [127,128] have also been known as useful features for target recognition.…”