You are currently browsing the archives for the Map Orientation category.

Categories

Calendar

February 2012
M T W T F S S
« Jan    
 12345
6789101112
13141516171819
20212223242526
272829  

Archive for the ‘Map Orientation’ Category

Map Orientation!

Thursday, July 22, 2010
posted by Bob 8:00 AM
Map Orientation!

Map/Compass/Ground Orientation!

A needed preliminary step to map/ground association is to orient the map with the lay of the land.  After orientation, if you plot your location on the map, and while doing it see  a hill top 2000 yards to the northwest, you should be able to look up and see that same hill top to your right-front at 2000 yards.

The method used to orient the map with the ground depends on what you’re doing. If all you want is a quick analysis, determine north (compass) and point the top of your map in that direction, and map is generally oriented. But, if you’re intention is to determine/plot directions or azimuths on the map and accuracy is critical, the method used should be exact, deliberate and allow no errors:

  • Place the map on a flat surface;
  • Open compass and place it (straightedge) parallel with a North/South grid-line.
  • Keeping the compass aligned, as directed above, carefully rotate the map/compass (together) until the magnetic arrow is below the fixed black index line of the compass (almost oriented);
  • To further compensate for the small Grid/Magnetic (GM) angle change, rotate map and compass in the direction of the magnetic arrow in the declination diagram. Whether movement is right or left, rotate the map/compass that small amount (degree/mils) indicated by the G/M angle. The number of degrees/mils of rotation will be reflected under the fixed index line of the compass.

The  map and compass are now oriented in accordance with map’s Declination Diagram.

Did you like this? Share it: