= - BS (SHCA) Project 6.1 - Accurate Location of an Electromagnetic Pulse wroee - b. A. Lewla OBJECTIVE To utilise the electromagnetic signal originating from nuclear weapon detonations to determine ground sero of detonation. Secondarily, to obtain the yield data that is available in the bomb pulse. PROCEDURE Location of ground sero is made by use of an inverse Loran principle. The exact tise the bomb pulse is received at various stations is recorded. The exact tine difference in receipt of the electromagnetic pulse betveen two stations vill be used to determine a hyperbolic curve which runs through ground sero. The point of intersection of two or more curves determines ground sero. There are two systems. One of the systems is known as the long tase line system and the other, the stort base line system. pets of stations. Each system hes tvo The long base line bas one set of stations located in the Rewailan Islands (Midway, Palmyra and Maui) with synchronising antenna station at Haiku, Maui, and the other set of stations in the States (Harlingen, Texas; Blytheville, Arkansss; Kinross, Michigan; and Rope, . New York) with a synchronising antenna station ot Cape Fear, North Carolina. The sbort base lines bave one set of stations located in the Havaiian area (Kons, Hawaii; Papa, Hawaii; and Red Hill, Maui) the otter set in California (Pitteburg, Woodland, and Maryville),