ATP-3-09-30 Observed Fires Download
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Target Location and Identification 28 September 2017 ATP 3-09.30 3-9 Table 3-1. Considerations in mental estimation of distance Conditions Where Objects Appear Nearer Conditions Where Objects Appear More Distant In bright light. In poor light or fog. In clear air at high altitude. When only a small part of the object is visible. Looking down from a height. Looking over a depression, most of which is visible. Looking over a depression, most of which is hidden. When the background is similar in color to the object. Looking down a straight feature, such as a road. When observing from a kneeling or sitting position on a hot day, when the ground is moist. Looking over water, snow, or a uniform surface such as a cultivated field. When the background is in contrast with the color of the object. Estimating When Visibility is Good 3-45. When visibility is good, estimate distances by using the appearance of tree trunks, their branches, and foliage (using the naked eye) in comparison with map data (see table 3-2). Table 3-2. Estimation by appearance of trees Distance (meters) Tree Description 1,000 Trunk and main branches are visible. Foliage appears in cluster like shape. Daylight may be seen through foliage. 2,000 Trunk is visible, main branches are distinguishable, and foliage appears as smooth surface. Outline of foliage of separate trees is distinguishable. 3,000 Lower half of trunk is visible. Branches blend with foliage. Foliage blends with adjoining trees. 4,000 Trunk and branches blend with foliage. Foliage appears as a continuous cluster. Foliage motion caused by wind cannot be detected. 5,000 and beyond Whole area covered by trees appears smooth and dark. Estimating by Using Known Dimensions 3-46. Distances can be estimated by using known dimensions of vehicles and the mil relation formula (R=W ÷ ₥). By using the width of a vehicle appearing perpendicular to an observer as the lateral distance (W) and measuring the width in mils (₥), the distance can be determined by solving the formula for range (R) in thousands, or R = W ÷ m/. This data, when compared with map data, will help an observer estimate distance. Observers should prepare quick reference tables of the dimensions of common pieces of threat equipment found in the operational area. Table 3-3 on page 3-10 provides the dimensions of selected equipment.