Velodyne VLP-16 - Sensor Data; Calculating X,Y,Z Coordinates from Collected Spherical Data

Chapter 9 • Sensor Data
This chapter provides detailed information about sensor data characteristics.
9.1 Sensor Origin and Frame of Reference 52
9.2 Calculating X,Y,Z Coordinates from Collected Spherical Data 52
9.3 Packet Types and Definitions 54
9.3.1 Definitions 54
9.3.2 Data Packet Structure 56
9.3.3 Position Packet Structure 60
9.4 Discreet Point Timing Calculation 61
9.5 Precision Azimuth Calculation 65
9.6 Converting PCAP Files to Point Cloud Formats 66
9.1 Sensor Origin and Frame of Reference
The sensor reports distances relative to itself in spherical coordinates (radius r, elevation ω, azimuth α). Sensor data origin
(0,0,0) is 37.7 mm above the sensor base, on the center axis, as shown in Figure 9-1 on the facing page (see the side and
top views), which also shows the sensor’s frame of reference. See also the mechanical/optical drawings in VLP-16 and
Puck LITE Mechanical Drawing on page 102 .
9.2 Calculating X,Y,Z Coordinates from Collected Spherical Data
A computation is necessary to convert the spherical data (radius r, elevation ω, azimuth α) from the sensor to Cartesian
coordinates. Figure 9-1 on the facing page lists the formulas for converting spherical coordinates (R, ω, α) to Cartesian
coordinates (X, Y, Z).
52 VLP-16 User Manual