Saturday, November 28, 2009

Managing Terrain in WorldWind Java - Trees in Denmark

Recently I talked to Thomas Knudsen from KMS, apart from discussing matlab vs octave and kriging vs other interpolation techniques. Finally we arrived at the topic he was presenting on, producing consistent DSM from Lidar. Lidar is notorious for the difficulty in tying multiple flightlines together, a problem KMS solved with their stock expertise in gridding (KMS pioneered a few variants of the kriging method). Interesting side note Picasa would not accept the picture as sent out of my iPhone - fix the bug in your Exif reader Google.


Thomas talked about the 2 Lidar companies they hired to collect the whole country since only 1 could not get the job done. I was reminded of the Scankort DSM data available via worldwind. Apparently Scankort went bust due to management failure and was gobbled up by Fugro. Somehow in the turmoil the data was released to NASA and is available for us to enjoy KMS's work.

For a few beers (not delivered yet) I hacked up a terrain manager to go with World Wind Java , so that you can turn the DSM on-off and compare with underlying SRTM. The results indeed show trees, while SRTM shows - well tree hills.

DSM

SRTM
 

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