Can someone point me in the direction of some high spatial resolution and reasonably recent satellite imagery for central Canada (Manitoba)? I am trying to determine whether I can generate accurate data of tree lines for residential properties for land surveys. The current procedure is for the guys in the field to take a few ambiguous shots of trees and for the CAD guys interpret them - often causing issues. Does anyone know if it is possible to determine tree lines using remotely sensed data? I am hoping I can manipulate the data in ArcGIS to create polygons of cover, and then overlay the tree shots on to the surveyed data.

Key requirements:

  • Relatively recent (no good if the trees have been pulled down since image was taken!
  • High enough resolution for residential lot level
  • Free (well at least until I work out whether it is feasible)
  • Would the National Air Photo Library have what you're looking for? (I've never worked with Canadian data myself, so can't speak to the coverage, resolution, and/or accessibility.) – Erica Sep 16 '14 at 12:04
  • How large of an area would you need coverage for? Also, defining the term "tree lines" would be helpful. – Aaron Sep 16 '14 at 19:35
  • Google Earth? Not very accurate, varying ages of photographs. – gomapping Sep 16 '14 at 19:58

Two potential options are: LANDSAT 8 which is operated by the US Geological Survey (http://landsat.usgs.gov/landsat8.php). It has 11 bands (I think) and a resolution of 30x30m. New images are available every 16 days. Second option is Bing satellite images. I'm not familiar with where to find them or the details, but our GIS guys use them and they have a resolution of 1mx1m. A quick Google search should reveal where to get them from.

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    Directing to Google isn't very constructive answer (IMO). Landsat has not high enough resolution for detecting trees (instead it can detect forest stands). Its temporal resolution is 16 days at best, but bear in mind that the images are disturbed by clouds very often. I'm afraid that high-resolution and free are not yet very common (I don't know about Canada, though).@Christography - maybe you guys have free LiDAR-data like we have here in Finland? (maanmittauslaitos.fi/en/maps-5 ).P.s. blogs.bing.com/maps/2013/02/28/… – reima Sep 16 '14 at 6:41
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    Apologies if directing to Google wasn't helpful, but to clarify, I was directing to Bing Satellite Imagery (via Google), which as stated previously has a 1mx1m resolution. And is free. – Matt Nuttall Sep 16 '14 at 7:22
  • I forgive you! I don't mind having to do my own legwork from time to time! – Christography Sep 16 '14 at 13:02

I can't think of anything free, but the spot5 satellite is high res and available from http://www.altalis.com/products/imagery/spot.html.

Those guys are a great source of data too. Mostly not free, but very good (Lidar, aerial photos, etc)

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Turns out I was over thinking the problem anyway - just need a meeting between the field guys and the CAD guys!

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