Occassional thoughts about orienteering

Tuesday, December 13, 2011

Kansas Orienteering Champs 2011


Joe ran the course with a headcam.

Back to okansas.blogspot.com.

posted by Michael | 7:54 PM


Monday, December 05, 2011

A quick base map


Here's a quick base map of the mountain bike/hiking trails at Perry. The area is small (the magnetic north lines are 150 meters apart). The contours (2.5 meters) are generated from OL Laser. The grey shading are Lidar slope from OL Laser (using all categories of data and last returns). The grey blobs cedar trees and groups of cedar trees in the forest. The trails are GPS tracks from a couple of trail runs.

Even without any field work, I think this will be a good map for some training. With a bit of field work it'll make a good addition to our local maps.

Back to okansas.blogspot.com.

posted by Michael | 8:29 PM


Sunday, December 04, 2011

Mapping runnability with lidar


I've been experimenting with trying to map vegetation - the runnability of the forest - from laser scan/lidar data.

The map below shows one of my tests. I created the map using OL Laser.  I used the software to measure  object heights. I created different colors to correspond to object heights. The yellow is ground height. In this particular map, the yellow areas are mostly open fields or open water. Then I created three other categories of object height. The lowest objects are shaded dark green. Medium height objects are light green. The heighest objects are white. I figured this shading scheme would roughly match runnability.

The map below shows highlights three different sections of forest.

Section A is an area that has a lot of low objects, with some yellow areas mixed in. This area turns out to be dense cedar trees. It would be mapped dark green on the final orienteering map.

Section B is an area with mainly tall objects. In this case, the tall objects are mature trees. The area has little undergrowth and would be mapped as white forest.

Section C is an area that is mixed. It doesn't have as many short (dark green) objects as A and it doesn't have as many tall (white) objects as B. This area would probably be a shade of green on the final orienteering map.

The tricky thing about mapping the runnability of the forest around here is that the changes are generally subtle. The shift from white woods to light green woods isn't very distinct and deciding where the mark the change is difficult for the mapper. The laser scan data might be a way to help see some of those distinctions.

I plan to do some more experimentation.

Back to okansas.blogspot.com.

posted by Michael | 9:01 AM


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