An employee of the GSDNR program recently received a call from an Ontario Provincial Police (OPP) officer who needed a topographic map as quickly as possible for the purposes of an investigation.

The police officer was looking for a map that covered an area of about 400 km² in the centre of Ontario, which was surrounded by a swamp, a road, and a few other landmarks. The police officer could not offer any geographical coordinates. To accommodate this emergency request, the GSDNR employee used commercial mapping software, from which maps taken from the NTDB at the scale of 1:50 000 can be used seamlessly, to translate the police officer's landmarks into geographical coordinates. These coordinates were then used to select the appropriate Landsat-7 image from the Geogratis site. The image was downloaded, enhanced, and cropped in order to produce a colour map covering the exact area of the investigation. Less than two hours after the call the police officer received the map by e-mail, produced thanks to the commercialization of mapping databases and the availability of free Landsat-7 images. The police officer's comment: "You are now on my list of best resources."

The GSDNR Communicator: Summer 2004