ATP-3-09-30 Observed Fires Download
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Chapter 5 5-38 ATP 3-09.30 28 September 2017 MEASURING AND REPORTING THE FIRST ROUND 5-105. When the observers report READY TO OBSERVE, the FDC directs the firing of the rounds one at a time. The FDC reports SHOT and SPLASH after firing each round. When the burst of the first round appears, each observer determines the direction to the round by spotting the horizontal deviation from the reticle vertical centerline in the reticle of the instrument and then combines this value with the reading on the azimuth scales. If the deviation is to the left of the reticle vertical centerline, subtract the value from the reading on the azimuth scales. If it is to the right of the reticle vertical centerline, add the value to the reading on the reading on the instrument. Example A round bursts 20 mils right of the reticle vertical centerline and the reading on the azimuth scales is 0480. The azimuth to the burst is 0500 (0480 + 20 = 0500). 5-106. The vertical angle to the burst is determined as discussed below. 5-107. If using an aiming circle the observer spots the number of mils the burst appears above or below the horizontal centerline in the reticle of the instrument and combines this reading with the reading on the elevation scales. Example The burst appears 10 mils above the reticle horizontal centerline and the reading on the elevation scales is +20. The vertical angle to the burst is +30 (20 + 10 = 30). 5-108. The observers report in turn. Example OBSERVER 1 DIRECTION 0500, VERTICAL ANGLE +30, OVER. OBSERVER 2 DIRECTION 0167, OVER. 5-109. If the observer does not observe the initial round within the field of view of the instrument, observer should report this, the approximate direction, and vertical angle to where the round burst to the FDC. Example OBSERVER 2 ROUND UNOBSERVED, TOO FAR LEFT, DIRECTION 0300, VERTICAL ANGLE +25, OVER. REORIENTING ON THE FIRST ROUND 5-110. Once the observer reports the direction (and vertical angle, if applicable) to the first round, the observer reorients the instrument (see figure 5-20) on the direction and vertical angle to where that initial round burst. This allows for smaller deviation measurements for subsequent rounds.