In a classical triangulation, the procedure for third order, class I accuracy positioning requires how many directions?

In a classical triangulation, the procedure for third order, class I accuracy positioning requires how many directions?

• A. 4
• B. 2
• C. 8
• D. 16

Answer: (A)

Redundancy in angular observations is essential for reliable positioning. In classical triangulation, reaching third-order, class I accuracy uses a setup that builds a pair of independent triangles sharing the unknown station. This arrangement provides the necessary geometric constraints plus redundancy, which supports a robust least-squares adjustment and helps control errors from instrument misleveling, observational bias, and local distortions. It also keeps the network well conditioned by avoiding degeneracy, where the station would lie in a problematic geometric alignment with its references. If too few directions are used, the station's position is underconstrained and error-prone; using more directions than needed adds workload without improving the precision. This balanced configuration delivers the required accuracy efficiently.

Redundancy in angular observations is essential for reliable positioning. In classical triangulation, reaching third-order, class I accuracy uses a setup that builds a pair of independent triangles sharing the unknown station. This arrangement provides the necessary geometric constraints plus redundancy, which supports a robust least-squares adjustment and helps control errors from instrument misleveling, observational bias, and local distortions. It also keeps the network well conditioned by avoiding degeneracy, where the station would lie in a problematic geometric alignment with its references. If too few directions are used, the station's position is underconstrained and error-prone; using more directions than needed adds workload without improving the precision. This balanced configuration delivers the required accuracy efficiently.