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 Chain and Offset
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    Intersection
 Angle-Angle Intersection
 Field Procedure
 Computations
 Multiple Stations
 Angle-Angle Simulation
 Radiation

Multiple Stations

Because there are only three quantities measured (two angles and a distance) and this is the necessary and sufficient solution for a triangle, there are no checks on the data. If one of the angles has been mis-read then the intersection will be incorrect and the computed location of the point will be offset from its true location.

To provide a check on the coordinates of the intersection point it is typical practice to measure intersection angles from more than two stations. Pairs of stations can be used to compute the intersection point coordinates as a raw check on errors in the measurements. The results from the different pairs of stations can then be used (for example, three stations allows three different pairs of stations are possible) to compute an average result for the coordinates of the intersection point.

A more rigorous computation process for the check is provided by a least squares estimation (LSE) solution of a survey network. The LSE solution uses all the data from the survey measurements and computes the coordinates of all the points of interest in the network of stations and measurements as a simultaneous calculation. The solution also provides estimates of the errors in the measurements and estimates of the precisions of the point coordinates.

If you wish to review the surveying methods or formulae used when performing a Angle/Angle Intersection procedure, they are described in more detail in the pages listed below.

Angular Measurement
Coordinate Geometry
Triangle Formulae