a 438 (RIF) Project 6.1 = Accurate Location of an Flectromagnetic Pulse Source F. A. Lewis QBSPCTIVE To utilise the electromagnetic signal originating from nuclear weapon detonation to determine ground sero of detonation. Secondarily to obtain the yield data that is available in the bomb pulse. PRNCyNITAP Looation of ground sero is made by use of an inverse Loran principle. The exact time the bomb pulse is raceivei at various stations is recorded, The exact time difference in receipt of the electromag- netic pulse between two stations wil] he used to determine a hyper bolic curve which rune through ground sero, The point of intersection of two or morc curves determines groum! sero. There are two systems. One of the systems is mown as the long base line system and the other, the short base line system, system has tvo sets of stations. fach The long base line has one set of stations located in the Havailan Telands (Midway, Palmyra, and Maul) with synchronising antenna station at Haiku, Maui, and the cther set of stations in the States (Harlingen, Texas; Blytheville, Arkansas; Kinross, Michigan ani Rowe, New York) with synchronising antenne atation at Cape Fear,-North Carolina, The short base lines have one set of stations located in the Hawaiian area (Kona, Reweiil; Papa, Hawaii; ant fet Ail}, Maul) the other set in California (Pittsburg, Woodland, and Maryville). RESULTS B E ST AV Short base line, - Be AILABLE COPY