Intelligence/Electronic Warfare (IEW) direction-finding and fix estimation analysis report. Volume 2: Trailblazer

Abstract : GUARDRAIL V (AN/USD-9) is a tactical, airborne, remotely-controlled radio emitter intercept and direction finding system which provides tactical commanders with near real-time intelligence information. The IPF (AN/TSG-105 VI) is the information processing and control center or sensor ground station of GUARDRAIL V. The IPF manages all mission functions and, through Tactical Commander's terminal, provides support to field commanders with near real-time location information on emitters operating within a specific RF spectrum in the surveillance area. This report contains an analysis of the direction finding (DF) and Fix estimation algorithms in GUARDRAIL software and in other current IEW systems. The report examines the underlying algorithm assumptions (including unmodeled errors) and their appropriateness for GUARDRAIL. Coding and documentation problems are then discussed. A detailed error budget is presented in Appendix B. An extensive bibliography on Fix estimation procedures is provided.