esriAdjustmentType Constants

Options for the type of adjustment calculation.

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Remarks

The esriAdjustmentTypeCompass technique specifies that the misclosure, or difference in x and y between the resulting endpoint and the desired endpoint, are equally distributed among the individual two-point arcs and curves that make up the traverse. This is done by adjusting the location and distance of each arc proportional to the difference in closure. The compass correction technique is the technique most often used to resolve errors in misclosure. It assumes that the errors are related to both errors in the direction measurements as well as the distance measurements. Thus, the corrections are reflected in each distance and direction value. This technique is also known as the Bowditch rule.

The esriAdjustmentTypeTransit method specifies that the misclosure is equally distributed among the individual two-point arcs and curves that make up the traverse. However, this technique favors the direction measurements over the distance measurements. In determining the location change required of each arc, the proportion assigned to each arc is proportional to the total x or y values of all the arcs. This results in changes that will affect both the direction and the distance of each arc but will alter the distance to a greater extent.

The esriAdjustmentTypeCrandall method is used when the direction values are assumed to be precise and accurate, and any misclosure is due solely to errors in distance measurements. This adjustment will preserve all the direction measurements and will alter only the distance measurements to eliminate the closure error. Since directions are fixed, the Crandall adjustment can result in unexpected results, such as flipped directions, very long distance adjustments, or no adjustment at all. Use an alternative method in these cases.