1

I have digitized vegetation as polygons covering the canopy of trees in urban areas. Are there any suggestions to check the accuracy of height. I have been manually validating with visual checks, comparing to google earth street view with kmz/kml, though these check are time consuming its the most reliable so far. Please advise if there are easier alternatives.

  • Have you assigned height based on field validation (i.e. using a Hypsometer) to all the canopy polygons? – Aaron Jun 4 '17 at 14:39
  • These heights are assigned as vegetation are digitized. The vegetation was digitized manually. – Jody Watson Jun 5 '17 at 5:01
  • If LiDAR data is available for your AOI, I would either 1) select the max point cloud return height within each polygon or 2) generate a LiDAR derived canopy height model and extract the max pixel value in each polygon. – Aaron Jun 5 '17 at 5:22
1

Google Earth uses SRTM DEM data as source of elevation for most part of the world (see here). DEM is mostly DTM, do not considers any object over the surface. So Google Earth might not be a good source for you. I'd recommend few ideas,

  • use high-res elevation data (ie. LiDAR)
  • volumetric shadow analysis
  • in-situ height information (ie. survey or inventory data)
  • high-res SAR Interferometry

In my opinion, a carefully sampled survey data might be a better source of information.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.