It is used as a reference number to link specific maps to overlays, operations orders, and plans. The sheet number is found in bold print in both the upper right and lower left areas of the margin, and in the center box of the adjoining sheets diagram, which is found in the lower right margin. A map is generally named for the settlement contained within the area covered by the sheet, or for the largest natural feature located within the area at the time the map was drawn.ī. The sheet name is found in bold print at the center of the top and in the lower left area of the map margin. These circled numbers correspond to the following listed items.Ī. The circled numbers indicate the items of marginal information that the map user needs to know. MARGINAL INFORMATION ON A MILITARY MAPįigure 3-1 shows a reduced version of a large-scale topographic map. All maps are not the same, so it becomes necessary every time a different map is used to examine the marginal information carefully. The most logical place to begin is the marginal information and symbols, where useful information telling about the map is located and explained. It is important that you, as a soldier, know how to read these instructions. If you think this is a valuable skill or just want to learn more, this link provides more information on using a map protractor with UTM grids.Chapter 3 MARGINAL INFORMATION AND SYMBOLSĪ map could be compared to any piece of equipment, in that before it is placed into operation the user must read the instructions. If you look closely at the picture above you will see the 1:24,000 scale lines up perfectly with the bottom and right borders of a UTM grid. You should have learned about sections in your high school geography class, if you were awake. A section is 640 acres and is 1 mile by 1 mile, so 4 contiguous red squares are probably a section. Red gridlines are land survey markings, usually (but not always) a quarter section. Keep in mind that if your map has the gridlines, these are the black grids, NOT the red gridlines. Most USGS Topo 7.5 minute maps printed in the past 30 years have UTM grids that are exactly 1 kilometer wide and tall, which exactly matches the 1:24,000 scale - how convenient! Older maps don’t have the grids, but many have tick marks in the margins. This would be useful for directing artillery fire or communicating to someone an exact point. If you understand and use UTM coordinates, which is beyond the scope of this post, you can use your map protractor to determine an exact point on the map. 100 meters = 109.36 yards (nine yards longer than a football field).10 meters = 10.93 yards (which would be a first down in football).If you are, then this conversion might help □ No math needed unless you are metric Luddite. Using the 1:24,000 scale, you can see the total length of the scale is 1 kilometer, major tick marks are 100 meters, and minor tick marks are 10 meters. My map protractor has 4 scales in the center: If we divide 24,000 by 12 (12 inches in a foot), we would get 2,000 feet - meaning 1″ on the map equals 2,000′ feet on the ground.īut since you have a map protractor, it can measure for you. Of course inches isn’t a good “on the ground” measurement. If you had a ruler, you could measure the kilometer or the miles scale and then measure the distance on the map and calculate. So 1″ on the map is equal to 24,000″ on the ground. is equal to 24,000 of the same measurement on the ground. What this means is a measurement on the map, be it inches, feet, millimeters, etc. The most common map, the 7.5 minute map has a scale of 1:24,000. Measuring DistancesĮvery USGS Topographical Map has a scale printed at the bottom of the map. For more information on compensating for declination read Part 1 and Part 2. In the picture above, the string shows our bearing as 55˚. The string will pass under the bearing reading. Align the map protractor along a north/south gridline, while stringing you line on top of points A and B. Tie a knot in one end of the string, and thread the other end through the center hole in the map protractor. No problemo! All you need is a piece of string, thin tent guyline, thread, or even dental floss. No Pencil or Straight Edge?īut what if you don’t have a straight edge and/or a writing instrument to draw a line? Then the map protractor is used to determine your bearing. If you recall, the first step is to draw a line between two points, A and B, A being your starting point and B your destination. In the post Set Up Your Compass Faster & More Accurately With A Map ProtractorI showed the readers how to navigate quicker and more accurately with a map and any compass using a map protractor.
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