GPS, triangulation, and traverse stations for basic, supplementary, and auxiliary control
Gun and target positions for artillery batteries.
Horizontal control to support PADS.
Points and lines of reference for locating details (such as boundary lines, roads, buildings,
fences, rivers, bridges, and other existing features).
A stakeout point to locate roads, buildings, landing strips, pipelines, and other construction
Parallel lines or lines at right angles to other lines. Identify the tracts of land, measure
inaccessible distances, or extend straight lines beyond obstacles.
Picture points for databases.
A need for work requiring the use of geometric or trigonometric principles.
2-22. Observations of Differences in Elevations. Topographic surveyors observe differences in
elevations for the following reasons:
For plotting projects and computing grade lines along a selected line.
To stake out grades, cuts, and fills for earthmoving and other construction projects.
For trigonometric elevations of triangulation and traverse stations for control nets and
To establish gun and target positions for FA batteries.
2-23. Field Notes (DA Form 4446). Topographic surveyors record field notes to provide a permanent
record of fieldwork. Even the best field survey is of little value if the field notes are not complete and
clear. The field notes are the only records that are left after the survey party leaves the field site.
Surveyors' notes must contain a complete record of all measurements or observations made during the
survey. When necessary, sketches, diagrams, and narration should be made to clarify notes. Write-
overs, erasures, or uses of correction tape or fluid are strictly forbidden. These actions, when prohibited
by the unit's standing operating procedure (SOP), are cause for punishment under the Uniform Code of
Military Justice. Recording errors should be lined out and initialed by the recorder, and the corrected
reading should be entered on the recording form.
a. Record field notes using one of the following methods: