ATP-3-09-02 Field Artillery Survey Download
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16 February 2016 ATP 3-09.02 7-1 Chapter 7 Survey Methods This chapter discusses the various methods that will be used to provide survey control to requiring units. IMPROVED POSITION AND AZIMUTH DETERMINING SYSTEM- GLOBAL POSITIONING SYSTEM 7-1. The IPADS or IPADS-G is the primary means for providing survey control. Instructions for use of the systems are located in TM 9-6675-349-13&P and chapter 8 of this publication. GLOBAL POSITIONING SYSTEM 7-2. The NAVSTAR Global Positioning System is a space based navigation and positioning system that provides accurate, three-dimensional position and velocity information, and time. 7-3. The space segment is made up of 30-32 NAVSTAR satellites that orbits the earth twice in a day. These satellites are deployed in six orbital planes and are configured so that four or more satellites will be in view at all times. This arrangement allows for 24-hour, three-dimensional, worldwide coverage. As with the stars, the satellites rise above the horizon about 4 minutes earlier than the previous day. 7-4. The control segment consists of five passive-tracking monitoring stations, active-tracking ground antennas, and the master control station. These tracking stations, located around the world, are capable of monitoring the satellite navigation messages and time signals better than 90 percent of the time. This information is relayed to the master control station, which has the capability to effect any needed corrections to the satellite timing and navigation messages. 7-5. The user segment consists of navigation receivers designed for marine, aircraft, handheld or vehicle use. The receivers must have electrical line-of-site with the satellites to receive and decode the satellite signals. The internal computer uses the satellite data to generate a precise time, velocity, and three- dimensional (3D) position data. The receiver must track four satellites to obtain a 3D position, and three satellites will yield a two-dimensional (2D) position. Current position coordinates and height are obtained from a 3D position and only current coordinates are obtained from a 2D position. The receiver needs only one satellite for precise time. GLOBAL POSITIONING SYSTEM METHOD 7-6. The AN/PSN-13(13A) DAGR is the receiver used by the FA Surveyor. The DAGR allows the surveyor to initiate surveys when existing survey control is not available. It allows more accuracy than assumed data or a map spot. When the DAGR is loaded with the correct encryption keys the required accuracy of 10 meters CEP is met. Notice that the 10 meter CEP does not meet the requirements for 5 th order survey. If this method is utilized then a more accurate method of survey needs to be prioritized in the survey plan. Position data should always be checked by another independent means; for example a second receiver, an accurate map spot or the correct coordinates on the IPADS or IPADS-G. The DAGR could determine height relative to either the horizontal datum ellipsoid (ellipsoid height) or mean sea level (elevation). The DAGR is not to be used to determine an orientation azimuth unless utilizing Dual DAGR Kit, Sub-MIL Azimuth Determination Dual DAGR Receiver NSN 5985-01-549-7219) system used by the USMC.