Hesai Pandar128, User Manual

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3.1.3 Point Cloud Data Analysis
The analysis of point cloud UDP data consists of three steps.
■ Analyze the vertical angle, horizontal angle, and distance of a data point
Take Pandar128's Channel 5 in Block 2 as an example:
1) Vertical angle of Channel 5 is 12.165°, according to Appendix I (Channel Distribution)
· 0° represents the horizontal direction
· Define upward as positive
· Channel # from the uppermost counts from 1
NOTE The accurate vertical angle is recorded in this LiDAR's unit's calibration file, see Section 1.3 (Channel Distribution).
2) Horizontal angle = current reference angle of the rotor + horizontal angle firing time offset
· Current reference angle of the rotor is the Azimuth field of Block 2
· Horizontal angle offset: 1.093° for Channel 5 , according to Appendix I (Channel Distribution)
· Firing time offset = Laser Firing Time of Channel 5 (See Appendix II) * Spin Rate of the Motor (see Section 4.1 Web Control - Home)
· Define clockwise in the top view as positive
NOTE The accurate horizontal angle offset is recorded in this LiDAR's unit's calibration file, see Section 1.3 (Channel Distribution).
3) Actual distance in real world millimeters = distance measurement * Distance Unit (4 mm)
Distance measurement is the Distance field of Channel 5 in Block 2
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