ATP-3-09-30 Observed Fires Download
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Observer Self-location Methods 28 September 2017 ATP 3-09.30 A-3 Example A24 (FDC) THIS IS A58 (OBS), SELF LOCATION, 1 ROUND, OVER. KNOWN POINT CADDO, DIRECTION 1743, DISTANCE 3180, VERTICAL ANGLE PLUS 10, OVER. 1 ROUND, GRID NK598376, OVER. (Round is fired and observed.) DIRECTION 2105, DISTANCE 3420, VERTICAL ANGLE MINUS 12, OVER. KNOWN POINT CADDO ON LEFT, OVER. A58 (OBS) THIS IS A24 (FDC), LOCATION NK47253824, DIRECTION TO CADDO 1723, OVER. Figure A-2. Self-location by use of one known point and one burst SELF-LOCATION BY USE OF TWO BURSTS. A-4. If no known points are available, the bursts of two rounds may be used as the prearranged points. The observer selects the locations at which he wants the rounds to burst, ensuring that they are separated by at least 300 mils (see figure A-3 on page A-4). Also, the direction to a reference point is determined. When the rounds are fired, the observer ranges the bursts to determine the direction, distance, and vertical angle of each burst point. The observer reports these to the FDC and records the direction to the second burst point. The FDC computes the laser rangefinder location and corrected azimuth to the second burst point and sends the information to the observer. The observer determines the difference between the measured azimuth to the second burst point and the azimuth that the FDC reported to the second burst point. The angular difference, in mils, is plus if the reported azimuth from the FDC is greater than the azimuth the observer measured. It is minus if the reported azimuth from the FDC is less than the azimuth measured by the observer. The difference is applied to the initial reference point azimuth by either adding or subtracting, as the sign indicates. The observer places the resulting azimuth on the laser rangefinder while sighting on his initial reference point.