The closure settings let you set the closure type, closing points and closing angle. These settings affect how TPC computes the closure information for this traverse.
Closure data is computed between the closing points. These are referred to as the Initial Point, Closing Point and Correct Closing Point.
The closing error is computed using the difference between the Closing Point and the Correct Closing Point.
You can display and edit the closing points in the Closure View.
TPC allows you to edit the closing angle in the Closing View.
TPC computes a number of closing errors including angular, linear, relative, etc. These are reported in the Error Summary section of the Closure View.
The three closure types used by TPC are Open, Closed Loop and Closed Point-to-Point.
You can also access the closure types via the Traverse Properties command.
You can trigger automatic closure settings by the way you enter data in the Traverse View.
The closed loop tolerance helps TPC determine if a traverse is a Closed Loop or Closed Point-To-Point traverse. The % Tolerance indicates the maximum error a Closed Loop can have and still be considered a Closed Loop. For example, if the total length of a traverse is 400 feet and it closes back on itself within 4 feet, this would correspond to a 1% Tolerance. Default = 0.10%
Until you specify a traverse to be a Closed, Closed Point-to-Point or Open traverse, TPC must determine whether or not the traverse is a Closed Loop. Once you specify a closure type for a traverse, TPC no longer uses the Closed Loop Tolerance for that traverse.
Only Closed Loop traverses are able to generate an area. Close Loop traverses can also compute an Error of Closure without any additional input from the user.
You can set your own closed loop tolerance in the Tolerances dialog.