SUBCOURSE EDITION - Modern Prepper

INSTRUCTIONAL CONTENT1. The term "control" used in mapping, refers to the established system of coordinated data, whichdetermines both the horizontal and vertical positions of specific points or features on the earth's surface.Control is necessary to tie the features on the earth to the UTM grid and geographic coordinate systems,and to establish the elevation of the terrain. Without control it would be extremely difficult, if notimpossible, to prepare an accurate map. Control points are plotted from DA Form 1959 (Description orRecovery of Horizontal Control Station) on a grid and projection base so that the map compiler canaccurately compile maps. During this lesson you will learn how to read and interpret the data from theDA Form 1959 necessary to plot control.2. DA Form 1959 Components. DA Form 1959 is used by the geodetic surveyor to record theprecise location and description of horizontal, and vertical control points. These forms are normallypublished in book form (known as trig lists) for a map sheet or sheets. The trig list is normallyfurnished to the cartographer as source material. The cartographer then plots, symbolizes, and labels allcontrol points contained in the trig list. Before continuing, examine the DA Form 1959 in figure 5-1 sothat you are familiar with the format of the form. The items highlighted are those items needed to plotgeodetic control.97