Map and Data Library, University of Toronto

Thursday, January 10, 2013

3D model of a real forest from airborne LiDAR - YouTube

Fantastic video tour through a French forest through a 3D model from airborne LiDAR
The thesis, available here, describes the methods and data used for the video.

Monday, December 31, 2012

“Path to Mobile’s Future May Be ... Maps” - Wall Street Journal - All Points Blog

Thursday, October 18, 2012

Missing Minching street. An error or a trap!?

In georeferencing a Fire Insurance Plan from 1909 today one of my students was having a really hard time matching Minching street with DMTI's Road Network file. DMTI has classified the road as a "5" in their categories of roads, which translates to a "local road".See the image below.

1909 Goad Fire Insurance Plan with CanMap Routelogistics (click to enlarge)

Google Maps view of the area. (click to enlarge)

The problem is, Minching street existed on the 1909 map and on the DMTI file, but in a different location and with a slightly different spelling (Minging). Overlaying Bing Maps we realized that the street actually no longer exists and was covered over by a building at the corner of Bay and Wellington streets. The building seems to contain the Design Exchange and Ernst and Young, according to google maps.(image on the left) Google is, of course, not immune from adding phantom locations on its maps either, have a look at this blog post.

What makes the addition of this road interesting is not only that the street once existed, but that it existed in a different location. About half a block west of where DMTI has Minching positioned, is the street in 1909. Our historical street data, compiled at the map and data library do not indicate the street ever existed prior to the 1890's.

The image below indicates that Bing Maps do not have Minching street in their road network data.

DMTI Routelogistics overlayed on top of Bing Streets (click to enlarge)

Bing map images shows a building on the site (image below).

Bing Aerial image with the DMTI streets overlayed on top. (click to enlarge)

OpenStreetMaps do not have the street listed either, see below

DMTI Routelogistics overlayed on top of Openstreetmaps. (click to enlarge)

The question then becomes, is this an error in the DMTI data, or did they put this street in their database as a copyright trap? Stay tuned for the answer once I get this question to them.