One of the elements of orientation on a paper topographic map is its comparison with the area. To compare a topographic map with a locality means to find on it an image of local objects and relief elements located around our location. And vice versa, to identify on the ground the objects shown on the map.
Comparison of a paper topographic map with the terrain, finding on the map the image of an object observed on the ground.
A comparison of a geographical map with a terrain occurs constantly when orienting it and working with it on the terrain. This allows :
Explore the area quickly and completely.
Identify changes that occurred on it that are not indicated on the map.
Clarify the location of observed goals, landmarks and other important objects.
Determine the distance to them.
In order to make a comparison and find on a paper topographic map an image of an object observed on the ground, you must:
Orient the map and determine its location on it.
Keeping the orientation of the paper topographic map, turn to face the object whose position must be found on the map.
Mentally draw a line from your location to an object visible on the ground.
Assess by eye the distance to it and set it aside on the map scale from the point of its location in the direction of the subject.
On the delayed distance, find the image of the determined object on a paper topographic map.
In the figure below, from the point of our location, the height is visible behind the forest. On a paper topographic map behind the forest in this direction, several heights are depicted behind the conventional symbol of the forest. By orienting the map and attaching the ruler to the point of our location, we sight at the height visible on the terrain. Having drawn a line along the ruler, we determine what height is visible behind the forest.
In order to solve the inverse problem, that is, to make comparisons and find out the localities of the object shown on the topographic map, you must also orient the map and find the point of our location on it. Then we determine from the map by eye the distance to the desired item and the direction to it, and according to these data we find it on the ground.
Based on the book “Map and Compass My Friends”.