Britannica
Sources used in this answer
How do surveyors use traversing to establish control points?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
surveying
Figure 1: Photogrammetric photographs from two short, overlapping flight strips arranged for supplying mapping details. Photo-control points are shown on only one photograph; shading indicates a typical terrain feature such as a lake (see text).
In civil engineering, a traverse is the simplest method for establishing horizontal control points. It consists of a series of marked stations connected by measured distances and the angles between them.1
To establish these points, surveyors perform the following steps:
- Connection: The surveyor connects a series of stations through measured courses. When this series returns to its starting point (a closed traverse) or begins and ends at stations of known, superior accuracy, it allows for the detection and adjustment of small measurement errors to ensure mathematical consistency.1
- Computation: By assuming or measuring the direction of one course and the rectangular coordinates of one station, the surveyor can calculate the rectangular coordinates for all other stations in the series.1
- Instrumentation: To ensure the necessary precision for the framework, surveyors typically use a theodolite to measure horizontal and vertical angles.2
- Marking: Once the coordinates are computed, the control points are physically marked on the ground using pillars, concrete markers, bolts, or wooden pegs. These points serve as the reliable foundation for subsequent detail mapping.2