Direction-finding using a laboratory experimental array testbed

Describes the performance of several direction finding algorithms using a laboratory sensor array testbed, constructed at the University of Minnesota. In recent years, many ´high-resolution´ direction-finding algorithms have been investigated using computer simulation and theoretical analysis. An experimental array testbed allows further evaluation of the capabilities and limitations of these algorithms. The system basically consists of a linear array of eight ultrasonic transducers and several transmitters operating at 40 kHz in air. Phase and gain errors, encountered in an actual array, require calibration in order to improve the results from ´high-resolution´ direction-finding algorithms. Methods of calibration are described. Experimental results are presented, which compare the performance of several well known algorithms, including MUSIC, ROOT-MUSIC, MIN-NORM, ESPRIT, and a weighted norm version of MUSIC called WMUSIC.<>