The Measurement of Point Target Speeds with Incoherent Non-Tracking Radar: Insect Speeds in Atmospheric Waves

摘要

A non-doppler method for the determination of the horizontal speeds of point targets crossing a circular radar beam is presented. It requires knowledge only of the range, the relative signal intensity variation with time, and the beam width of the radar. Dot angels, assumed to be insects, with observed 10 cm cross-sections of .00001 to .001 cm squared are found to have speeds from 0.9 to 5.0 m/sec. The high range resolution also permits accurate determination of the target vertical velocities from the time derivative of their height. Vertical velocities were found to range from -0.86 m/sec to +0.75 m/sec. The variation in both vertical and horizontal insect speeds of a selected group of insects correlates very well with the simultaneously observed radar heights of an atmospheric wave at about the same altitude as the insects. Due to a phasing difference it is concluded that the insects are moving in a direction opposite that of the wave perturbation. (Author)