User's Manual
Table Of Contents
- www.h
- Safety Notice
- 1Introduction
- 4Web Control
- 5PandarView
- 8Troubleshooting
- Appendix IChannel Distribution
- Appendix IIAbsolute Time and Laser Firing Time
- Appendix IIIPTP Protocol
- Appendix IVCertification Info
- Appendix VSupport and Contact
69
◼ Calculation
The absolute time of a Point Cloud Data Packet is calculated as the sum of date, time (accurate to the second) and μs time.
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Date andTimecanbe retrievedeitherfromthecurrentPointCloudDataPacket(6 bytes,year,month, date,hour,minute,second),orfrom the previous
GPS Data Packet (6 bytes of Date and 6 bytes of time).
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μs time can be retrieved from the current Point Cloud Data Packet (4 bytes of Timestamp)
NOTE The calculation of absolute time is different when PTP protocol is used. See Appendix III PTP Protocol.
II.2
Start Time of Each Block
Assuming that the absolute time of a Point Cloud Data Packet is t0, the start time of each block (the time when the first firing starts) can be calculated.
◼
Single Return Mode
The starttimeofeach blockdepends on the horizontalresolution –whether the LiDAR isoperatingin High Resolutionmodeor Standardmode(defined in
Section 4.4 High Resolution).
Block
Start Time (μs) in High Resolution Mode
Start Time (μs) in Standard Mode
Block 1
t0 + 3.148 - 27.778
t0 + 3.148 - 27.778 * 2
Block 2
t0 + 3.148
t0 + 3.148
◼
Dual Return Mode
The start time of each block is independent of the horizontal resolution.
Block
Start Time (μs)
Block 1 & Block 2
t0 + 3.148