In a static GPS survey, where is the base receiver placed?

• A. Over a point with precisely known coordinates, such as a survey monument.
• B. At a random location with unknown coordinates.
• C. On a moving vehicle to track dynamic changes.
• D. Anywhere with good satellite visibility, regardless of coordinates.

Answer: (A)

In static GPS surveying, the base receiver sits on a point whose coordinates are precisely known. This known position provides a fixed reference against which the base’s observations are compared, allowing accurate calculation of the baseline vectors and the satellite clock and orbit errors. Those corrections are then applied to the rover data to determine precise positions.

A survey monument or benchmark with published coordinates is typically used because it anchors the network to a geodetic datum. Placing the base somewhere random or on a moving vehicle wouldn’t give a stable, known reference, and simply having good satellite visibility isn’t enough to produce accurate corrections without a known base position.