When applying objects to the eye, on the oriented topographic map, they will first identify the landmarks or contour points closest to the object, estimate the distances and directions from them to the object, and observing their ratios, draw a point on the map corresponding to the location of the object. The method is applied if there are local objects shown on the map near the object.
Drawing on a topographic map of targets and other objects on the eye, in direction and distance, by direct notch and traverse.
When plotting targets and other objects on the map in direction and distance, first carefully orient the map at the starting point and use the ruler to draw the direction to the object. Then, having determined the distance to the object, lay it in the direction drawn on the map scale and get the position of the object on the map.
If it is impossible to graphically solve the problem, measure the magnetic azimuth to the object and translate it into the directional angle, along which they draw a direction on the map, and then lay the distance to the object in this direction. The accuracy of plotting an object on the map in this way depends on the errors in determining the distance to the object and drawing directions to it.
Drawing on topographic map of targets and other objects by direct serif.
At the starting point A, the map is carefully orientated, it is sighted along the line with the object to be determined, and the direction is drawn. Similar actions are repeated at starting point B. The intersection point of two directions will determine the position of object C on the map.
In conditions that make it difficult to work with the map, magnetic azimuths to the object are measured at the starting points, and then the azimuths translate the directional angles and draw directions on the map using them. The method is applied if the defined object is visible from two starting points available for observation.
Map objects with a direct serif.
The average position error on the object’s map, plotted with a direct serif, relative to the starting points is 7-10% of the average distance to the object. Provided that the intersection angle (notch angle) is in the range of 30-150 degrees. With notch angles of less than 30 and more than 150 degrees, the position error of the object on the map will be much larger.
The accuracy of applying the object can be slightly improved by notching it from three points. In this case, when three directions intersect, a triangle usually forms, the center point of which is taken as the position of the object on the map.
Drawing on a topographic map of targets and other objects by laying a course.
The method is used in cases where the object is not visible from any contour (source) point, for example, in the forest. At the starting point, located as close as possible to the defined object, they orient the map and, having outlined the most convenient path to the object, draw a direction to some intermediate point.
The corresponding distance is laid in this direction and the position of the intermediate point on the map is determined. From the obtained point, using the same methods, determine the position on the map of the second intermediate point and then, by similar actions, determine all subsequent points of the path to the object.
In conditions that exclude working with the map on the ground, first measure the azimuths and lengths of all the lines of the course, record them and at the same time draw a diagram of the course. Then, under suitable conditions, using these data, converting the magnetic azimuths into directional angles, plot the course on the map and determine the position of the object.
Mapping objects with a compass stroke.
If a target and objects are found in the forest or in other conditions that make it difficult to determine its location, the course is laid in the reverse order. First, the azimuth and the distance to the target C are determined from the observation point A, and then a path is made from point A to point D, which can be accurately recognized on the map.
In this case, the azimuths of the stroke lines are reversed. The reverse azimuths are to the directional angles and they build the course from a solid point on the map. The average error of plotting objects on a map in this way when determining azimuths by a compass, and the distance in steps is approximately 5% of the stroke.
Based on materials from the Handbook of Military Topography.
A. M. Govorukhin, A. M. Kuprin, A. N. Kovalenko, M. V. Gamezo.