Question

Mention any two ‘Scanning Errors’ in GIS.

Hint:

Check maps for folds or dust before scanning to avoid distortion and noise.

Answer 1

In Geographic Information Systems (GIS), errors arise during the digitization of hardcopy maps into raster imagery. A frequent issue is geometric distortion, which occurs when scanner movement is uneven or the map is not positioned flat. This results in feature misrepresentation, such as stretching, compression, or skewing, thereby compromising spatial accuracy. Another prevalent scanning error is noise and unwanted marks. Dust, abrasions, or stains on the original map can be captured, introducing extraneous speckles or lines into the digital representation. These artifacts can impede vectorization and analysis, necessitating subsequent data refinement. Implementing meticulous scanning procedures, regular calibration, and pre-scanning map cleaning are crucial for minimizing these errors.