PierreB <[email protected]> wrote: ... > In the meantime I found that the WMS Toporama Service provides maps > for all the zooms levels. The problem seems more one of Response-Time. > I wrote to RNCAN to see if it comes from their server. I succeed to > have map or some tiles at zoom levels 3 and 4. From 5 to 10, I rarely > obtain tiles. > > PierreB
I have experimented with these zoom levels from zoom=3 all the way into zoom=11 (and beyond). First I set the background color to bright red, so I could distinguish missing tile layers (background shows but no map layers) from simple lack of response. Availability of map layers 1) I got map layers all the way from z=3 to z=8. (some were very slow) These layers contain no topographic information but are general maps with province boundaries, roads, cities, etc. 2) I got no layers at all for z=9 and z=10 (only background). I waited till my status bar (on FF) said "Done". 3) Got the topographic maps already observed from 11 to 18. Projection vs tile size 1) with tile size=1000 (largest supported according to the web page) and zoom= 3 or 4 the projection was off by up to 1000 miles. I gave up and went to size=256. 2) with tile size =256 and zoom=3 to 8 the alignment with a known point (surveyed triangulation point) was close but still noticeably off at certain zoom levels. On the topographic maps (zoom >= 11) the location is spot on. Place names: Many place names were truncated on the left when the name was near the US border (to the right) but not truncated on the right in the opposite case. Background showing through: There are many areas in the topographic area (zoom >= 11) where the background shows through. This may be intentional, but since the background color is variable and set by the user it gives bizarre results. I would say there should have been another layer with the desired color behind these holes, Mirror site: No help at all. It returned nothing Instead of a link, I've made a number of screen shots: Screen Shot album link: http://picasaweb.google.com/papabear.newyork/CanVecGMaps# Specific examples: Projection problem - notice where the marker is - it should be on the border with Maine east of Sherbrooke. zoom=4, tile size=1000 http://picasaweb.google.com/lh/photo/9ebJjsn97ndcBEHtjA1NWA?feat=directlink zoom=4, tile size=256 http://picasaweb.google.com/lh/photo/VJmoffti39ZnGhCcJ14rZg?feat=directlink A vast improvement but still slightly off. If you switch to Google "Normal map" it's much better. Place names: http://picasaweb.google.com/lh/photo/ubfcz5gqY0_7GSr81vYYtQ?feat=directlink Notice "Fredericton" in New Brunswick is truncated to "dericton" but "Woodstock" is OK. Other examples are in other screen shots. Empty spots on the topographic maps with background showing through: zoom=11 http://picasaweb.google.com/lh/photo/kNFIYR---4huCEUCDuJZOA?feat=directlink zoom=16 http://picasaweb.google.com/lh/photo/uS-Zjg2lm59dWLK3RCELVA?feat=directlink I hope to get this information organized and email it to the folks at NR Canada. I know of one friend who has already sent something in and he received a very fast and thorough response. One last general question: is there a way to set the background to be transparent? If I could do that, I could overlay these maps on top of the USGS topos and get native topographic maps on both sides of the border. In other words, the NRCan maps would cover the USGS topos in Canada, but not in the US where NRCan produces no layers (at least for zoom >= 11). Regards Richard aka Papa Bear --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google Maps API" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/google-maps-api?hl=en -~----------~----~----~----~------~----~------~--~---
