How to catalog a scanned map
| Article Number: | 000001287 |
| Product: | DAP Administrator |
| Operating System: | Windows 2008 Server, Windows 2003 Server |
| Last modified date: | 2012-07-24 |
Objective:
I would like to catalog a scanned map.
Resolution:
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.
- First, Window the map so that you have a second file that only has the map portion. Take note of extents of this file.
- Take the original entire map image and add it to its own .ZIP file.
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Use the MDE to create the metadata XML file. When creating the metadata, use the windowed raster image to georeference the zip file.
This will ensure that the ZIP file will catalog in the correct location. - Submit the data package, ZIP file and metadata XML file, to the DAP data folder
- Use DAP Administrator to redirect the image for the ZIP file to the windowed map raster image file.
- Catalog the ZIP file.
