Basic Digitization Tips

Digitization is evaluated based on two parameters Quality and Quantity, Quantity can be measured by the total numbers of jobs done in relation to the total number of features captured, while quality is measured based on the aesthetics, compliance with spatial relationships, accuracy of attribution, accuracy of the digitized features and georeferencing.

These are the major factors that a QC looks for in a job. Usually depending on the number of errors the QC can make the required corrections or it will be sent back to the digitizer for rework, which

in lower evaluation of the Digitizer.

I believe that there are methods can reduce the chances of error occurring in the first place and Here are a few tricks that I used to ensure that the errors in my work was kept to a minimum.

1. Always have a dummy set of feature class in polygon and line that can be used to help in digitization.

2. While digitizing, I prefer to use line features almost always to capture the boundary of the parcels. This helps in overcoming snapping issues, gaps between adjacent polygons, overlaps, ambiguous boundary due to rasterization of the georeferenced files, etc. It also gives you the flexibility of saving our edits at any point which in case of polygons is not feasible, additionally in my personal opinion, lines can be digitized faster and with better accuracy than polygons.

3. If you are using line as mentioned above ensure that the line is captured to the center of the boundary as depicted in the georeff file.

4. During the digitization of the polygon boundaries, do not worry about snapping at the points of intersection, as long as it is a closed shape the polygons will be formed correctly.

5. Another advantage of this method is the elimination of tracing the same boundary twice, in case of the adjacent polygons, which would be required in most of the alternative methods. In this method, a single line feature will act as the boundary for both the adjacent polygons.