User's Manual

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3.1.3 Point Cloud Data Analysis
The analysis of point cloud UDP data consists of three steps.
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Analyze the vertical angle, horizontal angle, and distance of a data point
Take PandarXT's Channel 5 in Block 2 as an example:
1) Vertical angle of Channel 5 is 11°, according to Appendix I (Channel Distribution)
NOTE The accurate vertical angle is recorded in this LiDAR's unit's calibration file
Users can obtain the calibration file by sending the TCP command PTC_COMMAND_GET_LIDAR_CALIBRATION, as described in Hesai TCP API
Protocol (see Chapter 6)
2) Horizontal angle = current reference angle of the rotor + horizontal angle offset + firing time offset
· Current reference angle of the rotor: Azimuth field of Block 2
· Horizontal angle offset: 0° 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 the horizontal angles' positive direction
NOTE The accurate horizontal angle is recorded in this LiDAR's unit's calibration file
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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Draw the data point in a polar or rectangular coordinate system
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Obtain the real-time point cloud data by analyzing and drawing every data point in a frame