Bug 1248

Summary: LAS point cloud files are corrupt for GmAPD output
Product: DIRSIG4 Reporter: Scott D. Brown <brown>
Component: LIDARAssignee: Scott D. Brown <brown>
Status: RESOLVED FIXED    
Severity: enhancement    
Priority: P5    
Version: 4.7.2-release   
Hardware: Other   
OS: Other   

Description Scott D. Brown 2016-11-17 14:47:46 EST
When using the GmAPD detector model in the basic/general LIDAR detector tool, the LAS files produced are corrupted. This has been observed to include the incorrect number of points in the file and bad meta data fields the points.
Comment 1 Scott D. Brown 2016-11-17 14:51:21 EST
The issues was tracked down to how the Geiger mode detector model labels the return index for the time-of-flight triggers it produces. It was setting the return index to -1 for all triggers as a special flag that the return index has no meaning for GmAPD (it can only ever produces 1 trigger per pulse). The BPF writer was not not handling that special case and using the -1 as the return index (expected to be 0+) produced corrupt data fields.