ATP-3-09-30 Observed Fires Download
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Target Location and Identification 28 September 2017 ATP 3-09.30 3-13 ALTITUDE 3-51. Altitude is the vertical distance of a level, a point or an object considered as a point, measured from mean sea level or height above ellipsoid. Methods of measuring altitude include: imagery with a mensuration tool, map spot, vertical shift, and vertical angle. The meter is the standard unit of measurement for altitude using mensuration, map spot and vertical shift methods. Regardless of which method the observer uses, the observer must send the altitude of the target in the CFF. The standard for vertical angle measurement is mils. Some munition requirements vary between the use of Mean Sea Level (MSL) or Height Above Ellipsoid (HAE) for altitude. See ATP 3-09.32 for more detail. The usage of the terms “Altitude” and “Elevation” are used throughout this ATP with very similar meanings. However when conducting CAS operations the term “Elevation” is expressed in regards to a point affixed to the ground, and “Altitude” refers to in the air off of the ground (for example, operating altitude). When conducting Surface to Surface fires the usage of these terms are different. PRECISION IMAGERY WITH MENSURATION 3-52. Using imagery with a mensuration tool yields the most accurate altitude for target location. MAP SPOT 3-53. If measured from a map, determine the altitude of a target by use of contour lines and the contour interval of the map. VERTICAL SHIFT 3-54. Altitude may also be determined as a vertical shift from the altitude of the observer's position (or from a known point) to the target. If there is a significant difference in vertical shift (greater than or equal to 35 meters in altitude between the observer's position or a known point and the target), the observer includes the vertical shift in the target location (expressed to the nearest 5 meters). If the target is at a higher altitude than the observer (or known point) the observer determines an UP correction based on the difference in altitude (see figure 3-8). If the target is at a lower altitude, the observer must give a DOWN correction based on the difference in altitude. Figure 3-8. Vertical shift