Georeferencing Canada's Toporama maps
Canadians may be proud with their Toporama (http://toporama.cits.nrcan.gc.ca)
maps. Whole country is covered with rather high quality maps. Maps
are available at scales 1:250'000 and 1:50'000. And they are completely
free. One thing that is confusing why nobody has made them usable
with GIS?
Here are ESRI World files that can be used with any map downloaded
from Toporamaю
Download the map, convert it to something
acceptable by Arcview\Arcinfo software like TIF, JPG (default
GIF files are not supported) with any graphics software and put
corresponding TFW file in the same directory. After loading it as
a theme to Arcview you know get fully georeferenced map.
Download
World files, Coordinate sytem: NAD83
NB:
- Extension of the world file should be made of raster file
type.
For example: if it is TIF than the extension of world file should be TFW, if
JPG than JGW.
- Try to compress rasters with something like packbits or LZW (if you've
license) algorithm, this will save some space.
- Try to maintain uniform legend (colormap) for all maps, this will
shrink filesize and bring you functionality of this Arcview extension
(Transparent legend
- Canada)
Colormap:
(Photoshop palette file for custom indexing)
As you can see:
0 - symbols, marks etc.
1 - highways
2 - local roads
3 - settlements
4 - hydro (borders)
5 - hydro (fill)
6 - veg (fill)
7 - veg (border)
8 - relief (hypsography)
9 - snow, ice (permafrost) areas
10 - white areas, not covered with any special feature
Последнее обновление: August 01 2007 (Наверх)
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