For a second-order, class I geodetic control network, minimum triangulation station spacing is at least?

• A. 5.00 km
• B. 10.00 km
• C. 15.00 km
• D. 0.50 km

Answer: (B)

The spacing between triangulation stations is chosen to control how errors in angle measurements propagate through the network. For a second-order, Class I geodetic control network, a spacing of about 10 km is used as the minimum because it strikes a balance between geometric strength and practicality. If stations are placed closer than this, you increase work and cost without gaining meaningful accuracy in a second-order network; if they’re spaced farther apart, the triangles become too large and the angular errors can amplify into larger position errors, degrading the network’s precision. So 10 km serves as the standard minimum to ensure reliable network geometry and error propagation while remaining efficient to survey.