Book excerpt: This project included 146 ejecta measurement stations encircling ground zero at eight radial distances ranging from 373 to 1,707 meters. The twenty-four sampling lines were spaced at fifteen-degree intervals. Data presented were recovered from stations located at radial dis tances of 640, 853, 1,067, 1,280, and 1,707 meters. An attempt will be made to recover data at stations located closer to ground zero at a later time. Preliminary analysis of ejecta data indicates that a real density varies inversely as distance raised to the 3.64 power. Circumfer ential variation of areal density is about a factor of 30 at the 1,707 meter radial distance, a factor of 10 at the 1,280 meter radial dis tance, and a factor of 7 at the 853 meter radial distance. (Author).