ATP-3-09-02 Field Artillery Survey Download
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Chapter 7 7-2 ATP 3-09.02 16 February 2016 HANDHELD TERMINAL UNIT 7-7. The most important information the surveyor provides to both firing and target acquisition units is azimuth. If the surveyor has an HTU and a trigonometric list of survey control points he can perform a simple computation to determine accurate azimuth. Program A (Survey Calculations) on the HTU will compute an accurate azimuth and distance between two 4th Order or higher survey control points with only the easting and northing coordinates of the two points. You cannot compute azimuth and distance between two points established with the IPADS, or GPS. For use of this equipment refer to TM 11-7021-225-12&P. ASTRONOMIC OBSERVATIONS 7-8. As stated above, the most important information the surveyor provides to both firing and target acquisition units is azimuth. If the IPADS or IPADS-G is non-mission capable or unavailable the surveyor must maintain the ability to provide this critical information to all who require it. An IPADS or IPADS-G Team with a GPS, Theodolite, and a HTU (FOS device) can perform an astronomic observation to provide an accurate azimuth. PURPOSE OF ASTRONOMIC OBSERVATIONS 7-9. Astronomic observations can be used for, but are not limited to, the following survey operations: Checking the azimuth of any line in a survey. Providing orienting azimuths for cannons and associated fire control equipment. Determining azimuths for the declination of aiming circles. Providing orienting azimuths for radars and OPs. METHODS OF DETERMINING AZIMUTH 7-10. The artillery surveyor uses three basic methods to determine azimuth by astronomic observation. The three methods are artillery astronomic observation, hasty astronomic observation, and simultaneous observation. All three methods require a horizontal angle from an azimuth mark to the observed body in order to compute the astronomic azimuth on the ground. FIELD REQUIREMENTS FOR ASTRONOMIC OBSERVATIONS 7-11. Each of the three methods of determining azimuth by astronomic observation requires the measurement of the horizontal angle (see figure 7-1 on page 7-3), from the azimuth mark to the celestial body. Except for the method of sighting on the celestial body, horizontal and vertical angles are measured the same.