Traverse Processing

Various Copan modules allow you to process sets of field or map traverses. When you choose Calculate (or OK), each traverse is summarized in a Traverse Results window.

1. Field Traverse Results

Examine the Field Traverse Results and choose Coordinate Adjustment Rule.

The first number in the title bar is simply an auto-generated index for the traverse (if there are N traverses, they'll be numbered 1 - N).
The square bracketed numbers in the title bar are the start and end point numbers for the traverse (if it is a loop, they'll be the same).
If a closing (or redundant) angle is present, the Angle Misclosure will be shown, along with a note saying the Angles have been Adjusted. The overall angular correction is divided equally among the traverse angles.
The Total Distance of the traverse is shown next.
The large frame shows the Coordinate Misclosure — its Rectangular and Polar components, and the Relative Precision.
If any misclosure is larger than a certain tolerance, it is marked with a warning.

2. Map Traverse Results

Examine the Map Traverse Results and choose Coordinate Adjustment Rule.

The first number in the title bar is simply an auto-generated index for the traverse (if there are N traverses, they'll be numbered 1 - N).
The quoted name in the title bar is the optional traverse label.
The square bracketed numbers in the title bar are the start and end point numbers for the traverse (if it is a loop, they'll be the same).
If it is a non-looping, closing traverse, the overall Azimuth Error will be shown.
The Total Distance of the traverse is shown next.
The large frame shows the Coordinate Misclosure — its Rectangular and Polar components, and the Relative Precision.
If any misclosure is larger than a certain tolerance, it is marked with a warning.

3. Traverse Adjustment

To adjust the traverse (i.e., eliminate the coordinate misclosure), choose which Coordinate Adjustment Rule to use
- Compass (Bowditch) which allocates the overall coordinate correction to each point in proportion to its distance along the traverse,
- Crandall which adjusts the traverse distances but not the bearings, or
- Transit which adjusts the traverse distances more than the bearings,
then Yes. If there are subsequent traverses, the next one will be presented automatically.
To leave the traverse unadjusted and to see the next traverse, choose No.
To cancel this and subsequent traverse processing, choose Cancel.

Note, whether or not a traverse adjustment is made, a sum-of-angles imbalance, if present, has already been balanced prior to presentation of the coordinate misclosure.

4. Warnings

A very poor traverse closure will disable coordinate adjustment.

If any misclosure is larger than a certain tolerance, it is marked with a "Warning: Large Misclosure!"
If a misclosure is much (over 5 times) larger than the tolerance, it is marked with a "Warning: Very Large Misclosure!!"
If a misclosure is very much (over 10 times) larger than the tolerance, it is marked with a "Warning: Extremely Large Misclosure!!!" and subsequent adjustment is disabled.
You can modify the tolerances via the Geomatics section of the General Program Settings window. (Open it via the Settings... button on the Field Data Process or Map Traverse Adjustment windows or via the Program | Settings... | General... menu.)

5. Traversing Curves

A map traverse (i.e., containing reduced bearings and distances) can contain curves. See § Traversing Curves for details.

updated: 18-Jun-2009