The Network shall be designed so that all stations or points included therein have at least how many known PRS 92 control points?

• A. 4
• B. 2
• C. 3
• D. 5

Answer: (C)

The need is to anchor every station to the PRS92 datum using multiple known control points so the network can be positioned accurately in the reference frame. Having at least three known PRS92 control points for each station provides enough geometry to define the local coordinate frame (translation, rotation, and scale) and to give redundancy for error checking. With three non-collinear controls, you can robustly determine or verify the station’s position and detect outliers in observations; using fewer than three risks degeneracy (for example if the controls and the station become collinear) and reduces reliability. So, three is the minimum that ensures proper anchoring and a reliable network adjustment.