User's Manual

55
Appendix II Absolute Time and Laser Firing Time
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Absolute Time of Point Cloud Data Packets
For PandarXT, there are 8 blocks of ranging data in the Body of each Point Cloud Data Packet, as shown below.
Body: 1040 bytes (8 blocks)
Block 1
Block 2
Block 3
...
Block 8
Azimuth 1
Azimuth 2
Azimuth 3
...
Azimuth 8
Channel 1
Channel 1
Channel 1
...
Channel 1
Channel 2
Channel 2
Channel 2
...
Channel 2
...
...
...
...
...
Channel 32
Channel 32
Channel 32
...
Channel 32
Single Return Mode
The ranging data generated by one round of firing is stored in one block.
The absolute time of a Point Cloud Data Packet is the time when the LiDAR sends a command to trigger a round of firing that will be stored in
Block 8.
Dual Return Mode
The ranging data generated by one round of firing is stored in two adjacent blocks
· The odd number block is the last return, and the even number block is the strongest return
· If the last and strongest returns coincide, the second strongest return will be placed in the even number block
· The start time is the same for these two blocks
The absolute time of a Point Cloud Data Packet is the time when the LiDAR sends a command to trigger a round of firing that will be stored in
Blocks 7 & 8.