b. The primary system for distance data transmission on the battlefield is SINCGARS. DGPS is
designed to transmit encrypted GPS data over SINCGARS. Any user that can receive the data will have
a real-time correction to the broadcast GPS signal. This gives topographic surveyors the operational
capability to perform their mission under circumstances where GPS signals are dithered or spoofed on
the battlefield. A GPS signal can be retransmitted over a communication network to multiple users,
which extends the range and capability of survey operations.
2-31. Miscellaneous. Mirrors and lights can be used for communication. A signal mirror can use the
sun as a light source and a fairly accurate sighting device. Morse code or other prearranged signals can
be used to effectively communicate during the day. At night, the same signals can be used with a light.
PART K - SYSTEM ACCURACIES AND REQUIREMENTS
2-32. Geodetic Triangulation. Triangulation in which the shape and size of the earth are taken into
account is called geodetic triangulation. Geodetic triangulation is the highest form of survey
engineering, necessitating extremely precise instrumental equipment and observational techniques,
capable and conscientious personnel, and detailed computations. Geodetic triangulation is the most
efficient method of controlling surveys over extensive areas of the earth's surface and is used in the basic
horizontal control networks of the world. Triangulation is a method of surveying in which the stations
are points on the ground at vertices of triangles forming chains or networks. In these triangles, the
angles are observed instrumentally with highly accurate theodolites. The sides are determined by
successive computations through the chains of triangles from selected triangle sides called baselines, the
lengths of which are obtained from direct measurements on the ground.
2-33. Geodetic Triangulation Data. The data resulting from geodetic triangulation are primarily
horizontal control data, which are expressed in the form of geodetic latitudes and longitudes (or
equivalent plane coordinate values) of established points, including the distances and azimuths for all
observed lines. In order to obtain horizontal control data, you must know the precise length of the
starting line (either a measured base or an adjusted line of higher order), the latitude and longitude of at
least one end of the starting line, and the azimuth of the starting line. These points are normally marked
by bronze discs (most frequently set in concrete monuments) but may also include many prominent
objects, such as church spires, water tanks, and radio towers.
a. From the known line, triangulation stations are placed at the desired intervals, forming a series of
triangles. The angles are observed at the vertices of the triangles that form the triangulation stations. In
each successive triangle, one
2-17
EN0593
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