Pulse Doppler signature of a rotary-wing aircraft

A measurement research program was conducted to investigate rotary-wing aircraft Doppler radar signature phenomenology. Results of the data analysis program are presented with regard to classification and identification of a rotary-wing aircraft based on its Doppler radar signature. Using the return from a Doppler radar and appropriate frequency-domain signal-processing techniques, a rotary-wing aircraft´s design, such as main rotor configuration (single, twin tandem, twin coaxial, etc.), rotor parity (even/odd), tail rotor configuration (cross, X, star, etc.), and hub configuration (semi-articulated/fully articulated), can be estimated. Target backscatter from the main rotor blades, tail rotor blades, or hub region of the aircraft can be utilized by the modern radar processor for target detection, acquisition, and classification of the aircraft. Configuration and blade feature estimates can further define the helicopter for identification