DELETED'(semtno.z) Project 6.1 = Accurate Location of Electromagnetic Pulse Source E. A. Lewis OBJECTIVE To utilize the electromagnetic signal originating from nuclear weapon detonations to determine ground zero of detonation. Secondarily to obtain the yield data that is available in the bomb pulse, PROCEDURE location of ground zero is made by use of inverse Loran principle. The exact time the bomb pulse is received at various stations is recorded. The exact time difference in receipt of the electromagnetic pulse between two stations will be used to determine a hyperbolic curve which runs through ground zero. The point of intersection of two or more curves determines ground zero. There are two systems, One of the systems is known as the long base line system and the other, the short base line system, system has two sets of stations, Each The long base line has one set of stations locatei in the Hawaiian Islands (Midway, Palmyra and Maul) with synchronizing antenna station at Haiku, Maui, and the other set of stations in the States (Harlingen, Texas; Blytheville, Arkansas; Kinross, Michigan ani Rome, New York) with synchronizing antenna station at Cape Fear, North Carolina. The short base lines have one set of stations located in the Hawaiian area (Kona, Hawaii; Papa, Hawaii; and Red Hill, Maui) the other set in California (Pittsburg, Woodland, ani Maryville). COPIEDJp LANL RC OF - a~