Velodyne VLS-128 User Manual

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 53
9.3.1 Definitions 53
9.3.2 Data Packet Structure 56
9.3.3 Position Packet Structure 57
9.4 Discreet Point Timing Calculation 60
9.5 Precision Azimuth Calculation 62
9.6 Converting PCAP Files to Point Cloud Formats 65
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 66.11 mm (2.603 inches) above the sensor base, on the center axis, as shown in Figure 1
(see the side and top views), which also shows the sensor's frame of reference. See also VLS-128 Mechanical Drawing on
page 101 .
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).
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Velodyne VLS-128 Specifications

General

Brand	Velodyne
Model	VLS-128
Category	Accessories
Language	English