The Michigan automatic direction finder
David L. Mills · Deep Blue (University of Michigan) · 1964
This report describes the theoretical basis and practical instrumentation of the Michigan Automatic Direction Finder (MADFI). The MADFI is an integrated data collection, processing, and display system for determination of bearing statistics of signals in the high-frequency radio spectrum and is intended as a research tool in the study of propagation phenomena and direction finding techniques. Signal processing includes narrowband postdetection filtering and a type of linearly-weighted time averaging which improves the bearing estimates in the presence of multipath and noise processes. The MADFI is equipped with several types of readout suitable for telemetry transmission and computer processing of bearing statistics. (Author)