Accuracy of Points, Lines and Polygons¶

We use the calculated accuracy of points and utilize their accuracy to calculate accuracy for lines and polygons (areas). We then use error propagation based on partial derivation of formulas for the objects.

Points¶

The accuracy designation of a point is based on standard deviation for x, y, and h. Information about the error ellipse is not used in the calculations.

Info

The accuracy of points for plan and height is calculated when we approve a calculation.

The unit in the calculations is meter.

Lines¶

We can calculate accuracy on lines based on the accuracy of the measured points the line runs between. A line element consists of 1 or more line segments. There are two types of accuracy here, across the line and along the length of the line.

Note

The function requires that all points included in the line have a value for accuracy/height accuracy.

The transverse deviation is based on max. standard deviation for the points. The length deviation is based on error propagation based on the points' standard deviation.

The following values are calculated:

Transverse deviation
Height accuracy
Length deviation
Length deviation 3D

The option Calculate accuracy... is found in the tool menu of the horizontal list field for lines in a surveying application layer.

Polygons (areas)¶

We can calculate accuracy on polygons (area) based on the accuracy of the measured points the polygon runs between.

Note

The function requires that all points included in the polygon have a value for accuracy/height accuracy.

Accuracy is also calculated for composite areas and areas with islands.

The option Calculate accuracy... is found in the tool menu of the horizontal list field for polygons in a surveying application layer.