ATP-3-09-30 Observed Fires Download
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Adjustment of Fire 28 September 2017 ATP 3-09.30 5-37 5-100. For the high-burst registration, two observers (referred to as O1 and O2) simultaneously observe time fire aimed at a point in the air above the target. The FDC selects the point to observe. It does this by selecting the desired point of impact on the ground and projecting this point into the air with a prescribed HOB. The FDC controls the firing of the high-burst registration. The unit fires the registration with a single weapon firing the same data for all the rounds. Each observer, using an aiming circle or a laser designator and rangefinder reports the direction from their positions to the bursts. One observer reports the vertical angle after each round. An MPI registration is the same except the fuze used is fuze quick. LOCATION AND INITIAL ORIENTATION OF THE OBSERVING INSTRUMENTS 5-101. In a high-burst registration, the accurate location of each observation post and the proper orientation of each observing instrument are very important. Each observation post location is surveyed and a line of known direction is established on the ground so that the observer can orient the instrument for direction. If possible, the observer should establish the observation post and orient the instrument for direction during daylight. However, the exact location of the instrument and the line of known direction should be marked for easy identification during darkness. These precautions allow the observer to position and orient the instrument during darkness if necessary. To establish the observation post, the observer sets the instrument over the position marker, makes sure that the instrument is level, and then orients the instrument on the line of known direction. The observer sets the azimuth of the line of known direction on the azimuth scales of the instrument by using the upper recording motion. Then, using the lower motion, the observer aligns the reticle vertical centerline on the marker or the point that identifies the known direction. If using a laser, the observer places the vertical reticle edge on the known direction marker and uses the azimuth knob to put the known direction on the display. Once completed, the instrument is oriented for direction. ORIENTATION OF THE OBSERVING INSTRUMENTS ON THE ORIENTING POINT 5-102. The FDC tells each observer the direction and vertical angle from their positions to the orienting point. The example below is a typical message from the FDC to the observers. Example H18 THIS IS H44, OBSERVE HIGH-BURST REGISTRATION, OBSERVER 1 DIRECTION 1164, VERTICAL ANGLE PLUS 12, MEASURE THE VERTICAL ANGLE. OBSERVER 2 DIRECTION 0718, VERTICAL ANGLE MINUS 3. REPORT WHEN READY TO OBSERVE, OVER. 5-103. Each observer, using the upper motion, sets the direction given on the azimuth scales of the instrument. The horizontal line of sight of the instrument now coincides with the horizontal line of sight from the observer's position to the orienting point. Each observer also sets the vertical angle given on the elevation scales of the instrument to orient the instrument for HOB. The manner in which the observer sets the vertical angle on the scales of the instrument depends on the type of instrument being used. 5-104. The elevation scales on the M2 aiming circle are graduated so that a 0 reading on the scales corresponds to a vertical angle of 0. The scales are graduated and numbered in each direction from 0. The graduations and numbers in one direction from 0 are black; those in the other direction are red. Black numbers indicate positive (plus) vertical angles and red numbers indicate negative (minus) vertical angles. Operate the elevation scales on the aiming circles with the elevation micrometer knob. If the vertical angle given the observer is a negative (minus) angle, and sets its value on the elevation scales in the direction represented by the red numbers. This action places the intersection of the reticle vertical and horizontal centerlines of the instrument in line with the point in the air selected as the orienting point.