I’m happy to announce that a topo layer for the canadian rockies is finally live. The “nrcan” WMS source has always been available from the candian government, but I’ve wanted to create my own tiled source as well. Why?
- Toporama is a WMS layer hosted by Natural Resources Canada, and appears as “nrcan” on CalTopo.com. It’s a vector based layer – all the trails, contours, water features, etc. are stored as lines in a database and then turned into an image using a renderer like Mapnik.
- CanMatrix is scans of the original 1:50k Canadian topos. These are what the current layer is based on. Scan quality only supports going down to zoom 15.
- CanTopo is a newer, high-resolution round of topo maps. They appear to be computer-generated, probably from the same vector data that feeds Toporama, but coverage is currently quite sparse. Image quality supports going to zoom 16; as coverage increases, I will expand the USGS 7.5′ layer to include these.
Being a WMS layer, Toporama isn’t as speedy as I’d like. Although it’s better than the USGS’ vector data, side-by-side comparisons show that there are still a lot of missing trails and forest roads compared to the older paper maps. Some of the data leaves you scratching your head for context, like short unlabeled trails that start and stop in the middle of nowhere. And, being WMS, it’s not compatible with some of the tiled-dataset tools I’m working on like Google Earth Export. Not that you couldn’t make it work, but it’s more development effort.