This report addresses critical issues relative to the projected performance of Army users of the NAVSTAR Global Positioning System (GPS) in a battelfield environment. This study represents a continuation of an earlier Army user performance analysis conducted by TASC and reported in AFAL-TR-74-294. An assessment is provided of the practicality and navigation performance obtainable with the deployment of directional receiver antennas by the Army manpack user. A realistic assessment of ...