[Talk-ca] NTS sheet to lat/lon converter

Frank Steggink steggink at steggink.org
Fri Aug 21 03:37:30 BST 2009


Hi,

Because it is not obvious to everyone what the extent of the NTS sheets 
is, I've created a little service which converts them to lat/lon 
coordinates. It is also possible to show them directly as a box in 
OpenStreetMap. I'm not sure if a similar service exists (probably NRCan 
has one), but this might also be useful for the Geobase import.

The main entry page is at http://www.steggink.org/geo/
At the bottom you can enter the NTS sheet number. It can be done in the 
formats 'NNN', 'NNNL' or 'NNNLNN' where N is a number and L is a letter.

When you press the Submit button, you'll go to a page which shows the 
center coordinates. (No extent yet.) For example, entering '021L14' (the 
sheet containing Quebec City) leads you to 
http://www.steggink.org/geo/nts_area/021L14. From there you can go to 
various services accepting coordinates, like OSM.

When you press the OSM button in the main page, you'll directly see the 
result as a box in OSM. The "calculated" URL 
http://www.steggink.org/geo/nts_area/021L14/osmbox gets you redirected 
(HTTP 301) to the OSM site: 
http://www.openstreetmap.org/?minlon=-71.5&minlat=46.75&maxlon=-71&maxlat=47&box=yes

This means that you can also use the URL at my site as a template, 
replace the bbox, and you'll directly go to the OSM page. The next idea 
I had would be to using these URLs at the Geobase import status page, so 
everybody sees directly what area exactly was imported.

If you notice any errors (especially in the polar regions, due to the 
inconsitent box sizes), please report them to me. And yeah, this is not 
entirely RESTful, because errors are also returned as HTTP 200 - OK :)

Regards,

Frank




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