Abstract: A system and method is presented for detecting and classifying slow-moving and hovering helicopters from a missile's look-down Doppler radar that is compatible with the existing base of Doppler radars. This approach uses definable attributes of a helicopter rotor assembly and its extended Doppler rotor return to differentiate “rotor samples” from other samples (steps 123, 125), extract features such as bandwidth, activity, angle, and shape from the rotor samples (step 127), and classify a potential target as a helicopter or other based on the extracted rotor features and the known attributes of the helicopter rotor assembly (step 129). A target report including a classification target, range, range-rate, and angle of the extended rotor return is suitably passed to a tracking processor (step 121).

Abstract: A system and method is presented for detecting and classifying slow-moving and hovering helicopters from a missile's took-down Doppler radar that is compatible with the existing base of Doppler radars. This approach uses definable attributes of a helicopter rotor assembly and its extended Doppler rotor return to differentiate “rotor samples” from other samples (steps 123, 125), extract features such as bandwidth, activity, angle, and shape from the rotor samples (step 127), and classify a potential target as a helicopter or other based on the extracted rotor features and the known attributes of the helicopter rotor assembly (step 129). A target report including a classification target, range, range-rate, and angle of the extended rotor return is suitably passed to a tracking processor (step 121).

Abstract: A highly deacetylated chitosan obtained from microbial biomass, a method of obtaining chitosan from microbial biomass, and biomass for making chitosan are disclosed. The method includes providing chitin-containing biomass; reacting the chitin-containing biomass in a caustic solution of greater than 25 percent alkali at a reaction temperature greater than 95° C. for a reaction period of at least 10 hours to convert the chitin in the biomass to chitosan; and separating the chitosan from the caustic solution.