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

Radar cross-sections (RCS) of adults Of six insect species were measured with a high-resolution radar for selected aspect angles and polarization 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 grandis Boheman, respectively. Radar cross-sections varied from 3 cm2 to 5 x 10(-4) cm2 for an Apis mellifera (L.) queen and Elasmopalpus lignosellus, respectively. An example illustrates how mean RCS and polarization modulation can be used to develop an insect classification system. The results suggest that appropriately measured RCS properties can be used with altitude, time of flight, wing beating rate, flight direction, and true airspeed to define a classification system. Classification of radar targets could provide an estimate of the proportion of targets that have properties similar to a specific species.