okansas.blogspot.com Occassional thoughts about orienteering |
Saturday, December 27, 2008 Comparing Lidar base to the old O' mapHere is a comparison of the old orienteering map and the Lidar map I wrote about yesterday. We fieldchecked the old map a long time ago (1988-89, I think). The basemap we used was from the US Corps of Engineers. My memory is that it had 10 foot contour intervals. The quality was good.For anyone interested in Lidar, I would encourage you to download a couple of the free software tools that let you look at the data (Quickgrid and Global Mapper are the ones I've used), find some data, and see what you can do. I don't know much about finding data, but there is plenty of free data to download at the Kansas geodatabase catalog (look for bare earth data under "elevation" and use it to make contours in Quickgrid). Here is everything I've written about Lidar. Back to okansas.blogspot.com. posted by Michael | 9:41 AM
Comments:
Thanks for links! Quikgrid works really fast.
How do you convert contours generated by Quikgrid into file which can be used as template in Ocad? I haven't been able to find any reasonable solution yet.
How do the contours compare between the O' map and the LIDAR set in that one more detailed area of contours up top on the plateau?
In Quickgrid, open the Lidar file and then use "file" and "export a DXF file."
You should be able to import a DXF file into OCAD. I think it is under "file" then "import." Swampfox, the Lidar contours are better - more detailed and more accurate. I spent some time yesterday with some Lidar data that Eddie prepared for me and that data was amazingly detailed. I'll try to post something about it another day. Michael
Question: if I take the ascii data of puget sound consortium and use it in quikgrid, I usually end up with interrupted heightlines. it seems that the grid is somewhat not complete. quikgrid cannot open the e00 file format (whatever it is). global mapper does not allow to export. any solutions for that?
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