Understanding the Two-Point Problem in Plane Tabling

The two-point problem is a fundamental method used in plane table surveying. It is a technique employed when the position of the plane table station needs to be determined relative to two known points whose positions are plotted on the drawing sheet.

What is the Resection Method?

Resection is a method in plane tabling (and other surveying techniques) where the location of the occupied station is determined by taking sights to points whose positions are already known and plotted on the map or plan.

Objective of the Two-Point Problem with Resection

In the context of the two-point problem solved by the resection method, the surveyor sets up the plane table at an unknown station point. The objective is to accurately determine and plot the exact location of this unknown station point on the drawing sheet by referencing two specific points that are already plotted on the sheet and are visible from the unknown station.

Essentially, you have two points (say, A and B) marked on your map, representing real-world features whose locations are known. You are standing at a third, unknown point (say, P) with your plane table. The two-point problem using resection aims to find where point P should be plotted on the map so that it is correctly positioned relative to A and B.

Analyzing the Options

• Given location of two points, locating the station occupied by the plane table: This statement accurately describes the goal. You use the known locations of two points (plotted on the sheet) to find the location of the plane table station (the point where you are standing) on that same sheet.
• Locating the plane table station point: While this is partially correct, it's too general. Plane table stations can be located by various methods (like radiation or intersection from known points). The two-point problem specifies *how* the location is determined – using two *given* points.
• Locating two previous stations occupied by the plane table: This is not the objective of the two-point problem. The problem focuses on locating the *current* station using existing mapped points, not past stations.
• Locating the given point: The given points are already located (plotted on the sheet). The objective is to locate the station relative to these given points.

Therefore, the most precise objective of the two-point problem solved with the resection method is determining the location of the plane table station, given the locations of two known points which are already plotted on the map.