Rough Classification of Air-Target with the Theory of Blind Number

This paper first summarizes the difficulty in detecting and identifying helicopter, then analysis the spectrum signature of radar echo signal from helicopter, and estimates the width of the spectrum modulated by helicopter blades. The author uses the width of the spectrum and applies the theory of blind number to a rough classification of helicopter and fixed-wing aircraft. The author provides the result of emulation, and the result proves the effectiveness of theoretic analyses and the algorithm of classification.