1963 US Army Vietnam War Armor Operations ... - Survival Books

WWW.SURVIVALEBOOKS.COM(1) Primary. Every effort should be made as soon as feasible afer detonation to determineto obtain the following: ground zero. Readings of elevation to the(a) Height of the bottom of the cloud intersection of the stem and cloud bottom, ele-(intersection of the stem and bot- vation to the top of the cloud, and the azimuthstom of the cloud) at the time it to the edges of the cloud at its widest points arereaches its maximum altitude (ap- taken at 10 minutes after detonation. In theproximately 10 minutes after deto- absence of instruments, individuals will usenation) (fig. 84). field expedient methods for determining these(b) Ground zero location (by inter- measurements. Information outlined is subsectingazimuths, flash-bang-time,sectiong azimuths, flash-bang-time, mitted to the next higher headquarters by thesound ranging, or radar).most expeditious means.(2) Secondary. Efforts should be directedtoward measuring the followingparameters, in addition to the height6. Field Expedient Measurement of Anglesof the bottom of the cloud-When optical instruments are not available(a) Height of the top of cloud at the for measurement of angles required for the detimeit reaches its maximum alti- termination of burst parameters these anglestude (approximately 10 minutes can be estimated in mils by the observer holdingafter detonation) (fig. 84).his arm fully extended and measuring the angle(b) Cloud diameter at 10 minutes after in terms of a number of fingers (30 mils each),detonation (fig. 84).or fist (180 mils), or fingers spread (300 mils),(c) Height of burst-whether an obvi- as described in FM 6-40.ous airburst or surface burst.b. All units with optical equipment will 7. Nuclear Burst Sighting Reportorient their instruments on the site of the burst. The format for transmission of nuclear burs'A reading to the' center of the stem is taken measurements is contained in appendix V.CENTERLINE/9 I -',['' LOUDDIAMETER%.I CLOUD TOPCLOUD BOTTOMSTEM'GROUND jER- (HORIZONTAL)GROUND ZERO OBSERVER CLOUD TOP ANGLE OBSERVERCLOUD DIAMETER (MILS) (MILS) CLOUD BOTTOM ANGLE (MILS)Figure 84. Cloud measurements.358 AGO 9139A