Use of an adapted marine radar for the short-range detection and tracking of small birds in flight

As part of a project to develop an inexpensive songbird tracking and identification system, we have modified the antenna system of a standard marine radar to estimate the three dimensional position of point targets. Although the radar formally gives only two coordinate parameters, we show how the Incorporation of other information about the targets allows estimation of the full three dimensional position. We present two independent methods for this estimation. We have used this system in several field experiments at Prince Edward Point, Picton County, Ontario, Canada, where we have tracked various targets including a C-130 Hercules aircraft (RCS = 11 m/sup 2/) and 10-40g birds (RCS = 7-22 cm/sup 2/). Target locations were verified using an array of acoustic receivers to provide an independent measure of location.