Weather Radar Quantification of Bird Migration.

The article provides information on a study concerning the weather radar measurement of bird migration. It is known that radar becomes an important tool for the studies of bird migration. However, it is difficult to estimate bird densities from echo densities on the radar screen. The use of the Weather Bureau's new WSR-57 radar for bird migration research is also discussed. The shorter pulse of this radar has greater resolution but only detects birds when they are highly concentrated in the air. The fading of pulse radar signals reduces the number of perceptible returns because of the distribution of the numbers of targets among the radar.