Grid north may be symbolized by the letters GN or the letter y (Figure 6-1). the protractor on the vertical, north-south grid line. 0 with two known points plotted on the map, a. protractor, a straightedge, a pencil, and. (6) The intersection of the lines on the map is the location of the unknown point (C). This website uses cookies to improve your experience while you navigate through the website. c. Grid Convergence. 4. f. The location of the user is where the line crosses the linear feature. eQK/E!),HZ7^}-9mPkB"SJBvU[O7$L&Wq3/CPV-u9Ik0j^fIJ2Aryb:m=^N DK|cE< The cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. Figure 6-20. Google Maps compass routes can be saved and stored for later retrieval. Where the base line intersects the horizontal line, between 90 and 270 degrees, is the index or center of the protractor (Figure 6-6). This was deve. Military protractor. Identify the maps starting point (A). A declination diagram is a part of the information in the lower margin on most larger maps. Land Navigation - PowerPoint PPT Presentation - PowerShow Course Hero is not sponsored or endorsed by any college or university. Being in the right place at the prescribed time is necessary to successfully accomplish military missions. c. Using your compass, measure the magnetic azimuth to one of the known locations; change it to a grid azimuth (B, figure C-37.) Figure 6-18. Repeat the same process using a second known position that you can see from your location. how to determine grid azimuth using a protractor (b) Place the index of the protractor at the point where the drawn line crosses a vertical (north-south) grid line. All lines of longitude are true north lines. (3) Note that the protractor is cut at both the top and bottom by the same north-south grid line. This was developed for the Center for Initial Military Training, FT Eustis, Va. This problem is solved by grid north. The G-M angle is important to the map reader/land navigator because azimuths translated between map and ground will be in error by the size of the declination angle if not adjusted for it. Susan is 20 degrees off course. The declination diagram is used for these conversions. endstream endobj startxref The azimuth, 260, is more than 180, so subtract 180 from the azimuth. 124. Now, if you want to convert a MAZ to GAZ using the example above (in that you have a MAZ of 180, simply add the 15 degrees declination to the 180, and you have a correct GAZ. Identify the map's starting point (A). what day does pilot flying j pay; western power distribution. Using a protractor, draw a line for the back azimuth on the map from the known position back toward your unknown position. (4) Draw a line along the straightedge away from the known position on the ground toward your position. Identify an end point on your map. The consequence of not converting or adjusting for declination is not reaching your objective..or worse, getting hopelessly lost, which might be terminal, depending on your location and the scenario you find yourself in. Your back azimuth is 65 degrees, 180 degrees, and 245 degrees. Where all of the lines intersect on your map is your location. b. Align the 0- to 180-degree line of the protractor on the vertical grid line, while keeping the index in position. FM 3-25.26 Map Reading and Land Navigation - 550 Cord Identify two or three known distant locations on the ground and mark them on the map accordingly. a. The cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. This measured angle is the grid azimuth of the drawn line (fig. b. Align the 0- to 180-degree line of the protractor on the vertical grid line, while keeping the index in position. Plot Line From Point A to Point B. How do you calculate the azimuth of a line? Place the index of the protractor at the point where the drawn line crosses a vertical (north-south) grid line. 100 - 80 = 20. Land Navigation 4 - USMC OFFICER Figure 6-15. All Rights Reserved. (1) When working with a map having an east G-M angle: (a) To plot a magnetic azimuth on a map, first change it to a grid azimuth (Figure 6-10). When converting azimuths into back azimuths, extreme care should be exercised when adding or subtracting the 180 degrees. Overview of Navigation in the Military (land NAV and more) The GMA on a map from 1998 is 3 and half degrees. Bearing is a general term because it refers to an angle of separation between two points, whereas azimuth refers to a horizontal plane. The intersection of the lines on the map is your current location. These cookies ensure basic functionalities and security features of the website, anonymously. (d) Determine the value of the G-M angle. Ensure this line is at least two inches long to facilitate use of the protractor. You can find your PV systems azimuth by looking at Google Maps! Bearing can be expressed in milliseconds or degrees, while azimuth can be expressed in degrees frequently, if not always. (2) If it is an easterly G-M angle, add the . Draw an arc from the grid prong to the magnetic prong and place the value of the G-M angle (Figure 6-9). c. Field-Expedient Methods. SSG Black Land Nav - SlideShare Youve found your location. Especially from those who didnt get selected. Figure 6-9. There is an angular difference between the grid north and the magnetic north. 0 It is the angle between the vertical (north or 0) and the line between the starting point and the desired end point. 5. On the map, draw a straight line connecting the two points. Convert the grid azimuth to a back azimuth. Proceed as follows: a. Orient the map using a compass or by terrain association. (d) Remove the protractor and draw a line connecting the known point and the mark on the map. How to Use a Compass: Compass & Map Navigation Guide - Task & Purpose Draw a line along the straightedge away from the known position on the ground toward your position. Suppose you follow the 223 degree azimuth to the road junction, and then you want to go back to your original location. Figure 6-11. The grad is a metric unit of measure found on some foreign maps. Moving clockwise on a 360 degree circle, east has azimuth 90, south 180, and west 270. Convert the magnetic azimuth to a grid azimuth using the declination diagram. c. To obtain an accurate reading with the protractor (to the nearest degree or 10 mils), there are two techniques to check that the base line of the protractor is parallel to a north-south grid line. To express direction as a unit of angular measure, there must be a starting point or zero measure and a point of reference These two points designate the base or reference line. (1) To determine the grid azimuth (a) Draw a line connecting the two points (A and B). You must become a subscriber or login to view or post comments on this article. 5. As weve said here many times, land navigation requires as much prep and practice as any other perishable skill. Azimuth - See bearing. There are three base lines true north, magnetic north, and grid north. What does the code CL mean on my Maytag washer. *Lighting a path to truth* Former Navy JAG Worldwide U.S. Military Defense. How do you also convert azimuth to Army? Converting azimuths to quadrant bearings or vice versa is easy. a. Conversely, if its West, Magnetic North is West of your location. In some cases, there are no declination conversion notes on the margin of the map; it is necessary to convert from one type of declination to another. Align a protractor (left drawing) or the N-S or E-W directional axis of a compass (right drawing) with the map's border and read the bearing in degrees toward the direction of the destination. Next, you will plot an azimuth from a known point on a map. 2 Draw a line between these points. Draw a magnetic prong from the apex of the grid-north line in the desired direction (Figure 6-9). A star 45 degrees east of due north, for example, has an azimuth of 45 degrees. If a mistake is made and the reading is taken from the ending point, the grid azimuth will be opposite, thus causing the user to go in the wrong direction. Can you overlay a compass on Google Maps? Turn your entire body as a unit until your predetermined azimuth falls under the fixed black index line. a. The azimuth of the grid is defined. Read 0 degree on the top to this north-south grid line, and read 180 degree at the bottom to the same grid line. Using a protractor, draw a line for the back azimuth on the map from the known position back toward your unknown position. This is your grid azimuth from point A to point B expressed in degrees. 2287 0 obj <>/Filter/FlateDecode/ID[<01E97BD82B4A724EA381572D5ADBF101><24C8F5536AE732469D3285819F05CE2D>]/Index[2282 15]/Info 2281 0 R/Length 48/Prev 360229/Root 2283 0 R/Size 2297/Type/XRef/W[1 2 1]>>stream Look at the side of your map at the northing number and move up until you find the 95 grid line. 5. You then should be able to get an eight-digit grid coordinate and find your way to your point. 4a. Be sure to line the protractor up properly, keeping the cross-center lines of the protractor parallel with the grid lines. A back azimuth is a projectile of the azimuth from the origin to the opposing side of the azimuth circle. The following elements must be present when using polar coordinates (Figure 6-21). If you have a map and a compass, the one of most interest to you will be between magnetic and grid north. PRECISION LIGHTWEIGHT GLOBAL POSITIONING SYSTEM RECEIVER, Map Reading and Land Navigation REFERENCES. how to determine grid azimuth using a protractor YMMV. In order to measure something, there must always be a starting point or zero measurement. ?101rT$ > ` For mils, if the azimuth is less than 3200mils, add 3200 mils, if the azimuth is more than 3200 mils, subtract 3200 mils. The grad is divided into 100centesimal minutes (centigrads) and the minute into 100 centesimal seconds (milligrads). The cookie is used to store the user consent for the cookies in the category "Other. Task 071-510-0001 Determine Azimuths Using a Protractor Conditions Given a standard 150,000 scale military map with two known points plotted on the map, a protractor, a straightedge, and a pencil. how to determine grid azimuth using a protractor Such procedure is important when working with a map for the first time. A relationship can be established between degrees and mils. The magnetic azimuth is determined by using magnetic instruments, such as lensatic and M2 compasses. You will learn more about measuring angles later. The magnetic north is usually symbolized by a line ending with half of an arrowhead (Figure 6-1). To do so the successful navigator must follow these steps: This one sounds more difficult than what it truly is. The military definition of Resection for finding your exact location on a map by determining the grid azimuth to at two or more well-defined locations that can be pinpointed on the map. Then, using your scissors, cut out the printed protractor, cutting carefully along the straight line on the top edge. No mathematical equation is necessary because the compass itself has the declination already accounted for by your adjustment. The most accurate way to determine an azimuth from a map is to use a protractor. To determine azimuth, how do you use a protractor? (1) If it is a westerly G-M angle, subtract the number of degrees in the G-M angle from your magnetic azimuth. Grid Azimuth Step Action 1 Determine the start point and objective. True north is usually represented by a star (Figure 6-1). This dot should be inside of your original grid square. Locate at least two known distant locations or prominent features on the ground and mark them on the map accordingly. E move to or call a second known position from which (2) Connect them with a straight line. Next, you will plot an azimuth from a known point on a map. There are three methods of using resection, using the map and compass method, the straightedge method and the modified method. The University of Akron : YOU BELONG HERE! b. Align the 0- to 180-degree line of the protractor on the vertical grid line, while keeping the index in position. Our previous articles in the last week or so have centered upon getting back to the basics of land navigation. 3 Place protractor on the map, ensuring that it is correctly oriented (i.e., north on protractor corresponds to grid The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional". It determines the celestial bodys direction. (2) Locate at least two known distant locations or prominent features on the ground and mark them on the map. . Measuring an Azimuth Performance Steps 1. Box 378 Red Hook, New York 12571 United States. But also remember, that youll be only asked to pass the same course that thousands of other candidates have passed before you. This is the grid direction line (azimuth). The cookie is used to store the user consent for the cookies in the category "Performance". Determine the grid coordinates to the desired accuracy. Figure 6-7. Getting Back to the A-B-Cs of Land Navigation Resection. So, today well tackle a common issue for many candidates that find themselves on the land navigation course. Using a protractor, draw a line for the back azimuth on the map from the known position back toward your unknown position. 90 degrees is the temperature in the east (approximately where the sun rises). The angle at a given point in the plane of a rectangular coordinate system between the central meridian, or a line parallel to it, and a straight line to the azimuth point. Find a distant point that can be identified on the ground and on the map. Place the index of the protractor at the point where the drawn line crosses a vertical (north-south) grid line. How are azimuths used in a compass system? Convert the grid azimuth to a back azimuth. Declination diagram with arbitrary line. Draw a straight line on the map connecting the points, align the protractor to the map, and determine the value of the angle. Rotc-compiled - compiled - ROTC COMBINED PARA MADALI MAG CTRL F T9