Category Archives: GIS
proj.4 init annoyances: it’s all apple’s fault
I was going to write a rant about how Ubuntu sets up proj.4 init files incorrectly, then I found that the problem actually lies with OS X. OS X is unusual for a Unix variant, as it uses a case-insensitive … Continue reading
in which I discover OpenStreetMap editing
While I’ve used OpenStreetMap data before, I’ve never added anything to it. That changed after going to Mappy Hour last night, and meeting Richard Weait. He has a bunch of useful tutorials on his website. While I’ve used OpenStreetMap data … Continue reading
toronto data updated
Hey, they’ve updated most of the data sets on toronto.ca | Open! Hey, they’ve updated most of the data sets on toronto.ca | Open!
More on iPhoto GPS weirdness
Applications using Apple Core Image will alter any geodata stored in images, and should not be relied upon for GIS applications. Continue reading
Don’t trust iPhoto’s exported GPS coordinates
John the new jersey geographer put this better than me, but it appears that iPhoto rounds exported GPS coordinates to the nearest integer second of arc. There’s really no reason for them to do this, and it’s caused me to … Continue reading
The highest point in Toronto
The highest point in Toronto has an elevation of 211m, and appears to be in the middle of one of York University‘s playing fields, just southwest of Keele & Steeles W: The red blob is the 211m contour, and the … Continue reading
MNR DEM tiles
So I got the DEM tiles for my zone, couriered from Peterborough. Even zipped, they are several gigabytes. Here’s a visual guide to the tiles I got: It seems that every project I work on is split across several tiles. … Continue reading
Land Information Ontario – or, how I semi-accidentally ordered 3.5GB of terrain data
The Ontario Ministry of Natural Resources has a fairly well-hidden service that provides free geodata to the general public. One has to register with a sign and e-mail form, but there’s a large number of useful data sets available. The … Continue reading
untangling CanVec
It’s almost as if NRCan doesn’t want anyone to use CanVec. I mean, it’s a free and comprehensive data set for the whole country; anyone who can type in a postal code and click a couple of times can download … Continue reading
use and abuse of elevation contours
I’d never really looked at elevation in GIS data before, mainly because the data sets are big and I didn’t understand the format. I believe that in GeoGratis, NTDB and its successor CanVec provide elevation data, but those are vector … Continue reading