results were satisfactory. However, cloud cover, usually present at low altitudes over the EPG, made it difficult to obtain photography to the desired degree of success. However, this lack of data was supplemented by the use of less-accurate data from photo- graphic film from another source. No film was usable from Shot 3 because of the low yield of the device and the poor visibility at the time of the shot. Pressure-distance data vertically above the shot were obtained only on Shot 2. Be- yond the fireball, data was measured in the region from 10,000 to 15,C00 feet. Two wave fronts were alao observed at very-high altitudes (~ 265,000 to ~ 335,000 feet). The first wave probably was the blast wave; the second was presumed to be an acoustic wave. The low-altitude (10,000 to 15,000 feet) data are plotted in Figure 2.6; these data are compared Water Line Snot | sre @ BRL NOL Land Line NOL Water Line $¢ @re@e of O NOL s¢ NOL sc BRL Snot 2 BRL > NOL Water Line 7s © BFL 1 | Overpressure , psi i a SC @ SRL ° lwy Mike » Jongle 500 4000 Range , Feet Figure 2.4 Composite overpressure versus scaled ground range, Shots 1 through 6. to theoretical pressure-distance curves which were constructed using the TheilheimerRudlin Naval Ordnance Laboratory (NOL) method for considering the variation of the pressure-distance relation with altitude, which involves the determination of an equiva- lent TNT charge radius. The upper theoretical curve for Shot 2 in Figure 2.6 is based on an average change radii of 404 feet for the surface-level data obtained by Project 1.2a with electronic gages. The lower theoretical wave is based on an average charge radii of 349 feet for the surface-level data obtained by Project 1.la with rocket-trail photo~