Northern Prairie Wildlife Research Center
William W. Cochran, George W. Swenson, Jr., 1308 West Main Street, Urbana, IL 61801-2307 USA, and Larry L. Pater, U.S. Army Construction Engineering Research Laboratory, 2902 Newmark Drive, Champaign, IL 61821 USA
The direction finding performances of a non-rotating switched array of six 3-element Yagis (3n6) and of a rotated twin 6-element Yagi interferometer (6r2), each in computer automated mode, were evaluated and compared.
Findings agree with theory; (6r2) is about 7 times more precise than (3n6) for the same transmitter power and distance. Compared in another way, (6r2) can obtain directions at 4 times the distance (16 times area coverage) and 50% better precision than (3n6). For both antenna types, precision was approximately proportional to the square root of the product of number of transmitter pulses averaged and pulse width.
Comparison was also made with human operators using the (6r2) antenna. For the same range and transmitter power, humans were about 4 and 16 time more accurate than the automated (6r2) and (3n6), respectively.