W W W . K A A R T A . C O M
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Pla yback
The lidar on Stencil Pro operates at 10 hz, however to operate in real time, Stencil Pro
processes lidar data at 5 Hz. Normally, this data is dense enough for most applications
and is the maximum density available in real time. The raw lidar data recorded by Stencil
Pro in the bag file is at the full 10 Hz rate and can be processed to use the full 10 Hz in the
resulting registered point cloud. With bag replay or “playback” on Stencil Pro you can
replay the raw lidar and IMU data at an optimal rate (and/or with different parameters
than used during live scanning) to allow the device time to process each frame, without
real-time constraints. The rate of processing is “adaptive,” meaning that it fully processes
each frame of data before moving to the next frame. Some of the frames are processed
at faster rates than live scanning, while most take longer. As required, the frame rate is
slowed down to allow a full solution to be achieved on more difficult frames. Slower
speeds are extremely helpful in producing better maps and can register a scan where it
may have failed in real time.
It is highly recommended to use playback on every scan, given the many benefits
replaying the bag file can provide. The benefits of playback include:
•
Increases point cloud density and accuracy without the constraints of real time
processing
•
Retrieves more exact timing data values
•
Can maintain registration in areas of a live scan where the data was mis-registered
due to sparse 3D features, tight environments, or other issues affecting registration
in real time
Figure 43: Playback presets.