INSECT RADAR CROSS-SECTIONS FOR AERIAL DENSITY-MEASUREMENTS AND TARGET CLASSIFICATION

Radar cross-sections (RCS) of adults Of six insect species were measur ed with a high-resolution radar for selected aspect angles and polariz ation angles. These data were fit to transcendental equations relating RCS to aspect angle or polarization angle. Insect weight ranged from 256 mg to 10 mg for Helicoverpa zea (Boddie) and Anthonomus grandis gr andis Boheman, respectively. Radar cross-sections varied from 3 cm2 to 5 x 10(-4) cm2 for an Apis mellifera (L.) queen and Elasmopalpus lign osellus, respectively. An example illustrates how mean RCS and polariz ation modulation can be used to develop an insect classification syste m. The results suggest that appropriately measured RCS properties can be used with altitude, time of flight, wing beating rate, flight direc tion, and true airspeed to define a classification system. Classificat ion of radar targets could provide an estimate of the proportion of ta rgets that have properties similar to a specific species.