|Operating System:||Windows 2008 Server, Windows 2003 Server|
|Last modified date:||2012-07-24|
I would like to catalog a scanned map.
As part of the cataloging process, the extents of grids and images are always reprojected to WGS 84 Lat/Long. If there is a problem reprojecting the grid or image, then the file will fail to catalog and you will receive an error. For this example, we will look at scanned maps as consisting of two main parts. The first is the map image itself for the area of interest. The second part is the rest of the map that has items such as a legend, diagrams, information about the map, titles and subtitles etc.
A problem can arise when the map image portion of the scanned map is used to digitize coordinates to georeference the map. The software does not know the difference between the map itself, and the additional components such as the legend etc. When the map portion is used to digitize location, the rest of the sheet is also georeferenced as if it were an extension of the map as well. When the cataloging process tries to reproject the extent of the entire map sheet from the coordinates system of the map to WGS84 Lat/Long, there is no mathematical solution and hence the cataloging process will fail.
The way around this is to create a .zip file for this scanned image of the map and reference it using only the coordinates of the map portion of the map sheet, not the entire sheet.