The Closure View handles all the traverse summary and adjustment functions of TPC. To open the Closure View, open the Traverse View for the traverse you are interested in, then choose the Closure View command.
The Closure View always displays the current status of the traverse. If you have not yet applied any adjustments, it displays the raw closure, area and length. If you balance coordinates, the Closure View will display the balanced closure, area and length.
The Traverse View also displays the current status of the traverse with the exception that you can display raw data at any time in the Traverse View.
The Closure View computes its summaries and adjustments starting with the Initial point (From) and ending with the Closing point (To). Together these are referred to as the Closing Points.
By default, TPC sets the Initial point to the first control point in the traverse and the Closing point to the last control point in the traverse.
To work with just a section of a traverse, choose Edit | Closure Settings | Closing Points. This brings up the Closing Point dialog. Recall the points you want to adjust From and To and choose OK. The Closure View will display the summary information using the new closing points and any adjustments made will affect only these points. Use this command to balance a traverse that runs through several known points in sections.
If you return to the traverse and add or delete points, the closing points will be reset to their default values.
To display the closing points in the Closure View, choose View | Include Closure Data | Closing Points
Choose Edit | Closure Settings | Closing Angle to display the Closing Angle dialog.
TPC computes the difference between the computed and correct bearing/azimuth to get the angular error. This is the angular error that will be displayed in the Closure View. When you balance angles, TPC prorates the angular error among all the angles, including the closing angle.
Note: Angles are not actually balanced until you choose the Balance Angles command.
To see what the adjusted closing angle is after you have balanced the traverse, return to the closing angle dialog box. TPC remembers the closing angle you entered. If you undo all adjustments after the traverse has been balanced, this dialog box will display your original closing angle.
The three closure types used by TPC are defined as:
Open traverses may start at a known point, but end at an unknown point. Open traverses cannot be balanced, but can be adjusted for curvature, refraction, and horizontal distance factor.
Closed loop traverses begin and end at the same occupied point and in most cases, use the first course of the traverse for the closing angle. TPC uses the Closed Loop Tolerance to determine whether or not a traverse is a Closed Loop. A tolerance of 10% would consider any traverse with a 1 in 10 error of closure to be a Closed Loop. Once you specify a closure type manually, TPC no longer uses the Closed Loop Tolerance.
Closed point-to-point traverses begin and end at different known points and can include a closing angle to any known point or bearing/azimuth. TPC cannot compute the correct closure errors until you tell it the correct closing point (choose Edit | Closing Points).
To change the closure type choose Edit | Closure Settings | Closure Type to display the Closure Type dialog. Select the closure type you want and choose OK.
You can recompute the coordinates of a traverse using a specified precision, such as 0.1 feet or 10 seconds. Use this to check the closure based on the same bearing and distances plotted in your drawing. See Applying Precision
If you have adjusted a traverse, you can always undo the adjustments you have made. TPC does this by retaining the raw data with the traverse and simply recomputing the traverse using the raw data. This cancels any adjustments that have been made to traverse points including the closing angle, if you entered one.
You can use this option to cancel all adjustments and start over again.
One side effect is that any rotated or translated points in the traverse will be unrotated or untranslated as they are recomputed.
Check the area and perimeter of the traverse
Check the raw closure
Curvature and Refraction
Applying a Scale Factor