Bug 1046 - Trees in Forest and Urban scene do not show up in LIDAR simulations
Summary: Trees in Forest and Urban scene do not show up in LIDAR simulations
Status: RESOLVED FIXED
Alias: None
Product: DIRSIG4
Classification: Unclassified
Component: LIDAR (show other bugs)
Version: 4.5.0-release
Hardware: Other Other
: P5 normal
Assignee: Scott D. Brown
URL:
Depends on:
Blocks:
 
Reported: 2013-07-09 11:51 EDT by Scott D. Brown
Modified: 2013-07-09 11:54 EDT (History)
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Description Scott D. Brown 2013-07-09 11:51:04 EDT
If you simulate a LIDAR instrument over either the Forest or Urban scenes, the trees do not appear to exist.  The resulting point cloud appears as though the trees are not even there.
Comment 1 Scott D. Brown 2013-07-09 11:53:06 EDT
This had to do with how the leaf transmission was configured. The LIDAR radiometry solver imposes strict conservation of energy and the classic radiometry solver (used for the passive simulations of those scenes) preserves some DIRSIG3 era assumptions about the reflectance always being 1-emissivity ... even when transmission is present.
Comment 2 Scott D. Brown 2013-07-09 11:54:13 EDT
The fix was to return to the extinction description of the leaves which correctly behaves with all the radiometry solvers.  In addition, the Forest and Urban scenes were cleaned up to removed unused material descriptions and files.