Types of Errors & Location Errors and Their Source (Especially for GATE-Geospatial 2022)

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Types of Errors

The removal of error from and updating of digital maps it covers two types of errors:

This Diagram Shows Types of Errors

Location Errors and Their Sources

It describes three common scenarios.

This Diagram Shows Three Common Scenarios
  • The first is human errors in manual digitizing. Human error is not difficult to understand: when a source map has hundreds of polygons and thousands of lines, one can easily miss some lines, connect the wrong points, or digitize the same lines twice or even more times.
  • The second scenario consists of errors in scanning and tracing. A tracing algorithm usually has problems when raster lines meet or intersect, are too close together, are wide, or are thin and broken. The thin lines are lines on the source map, and the thick lines are lines from tracing.
This Image Shows Types of Digitizing Errors from Tracing
  • The third scenario consists of errors in converting the digitized map into real-world coordinates.

To make a check plot at the same scale as the source map, we must convert the newly digitized map into real-world coordinates by using a set of control points. To correct these types of location errors, we must re-digitize control points and return geometric transformation.

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