Velodyne VLP-16 - Sensor Operation

Chapter 8 • Sensor Operation
This chapter provides details on the laser firing sequence, point density, and how to determine throughput rate and angu-
lar resolution.
8.1 Firing Sequence 49
8.2 Throughput Calculations 49
8.2.1 Data Packet Rate 49
8.2.2 Position Packet Rate 50
8.2.3 Total Packet Rate 50
8.2.4 Laser Measurements Per Second 50
8.3 Rotation Speed (RPM) 50
8.3.1 Horizontal Angular (Azimuth) Resolution 50
8.3.2 Rotation Speed Fluctuation and Point Density 51
8.1 Firing Sequence
All 16 lasers are fired and recharged every 55.296 μs. The time between firings is 2.304 μs. There are 16 firings (16 ×
2.304 μs) followed by an idle period of 18.43 μs. Therefore, the timing cycle to fire and recharge all 16 lasers is given by (16
× 2.304 μs) + 18.432 μs = 55.296 μs.
Figure 8-1 Firing Sequence Timing
8.2 Throughput Calculations
Some terms used here are defined in Packet Types and Definitions on page 54 .
8.2.1 Data Packet Rate
There are 24 firing cycles in a data packet. 24 x 55.296 μs = 1.327 ms is the accumulation delay per packet.
1 packet/1.327 ms = 753.5 packets/second
1248 bytes/packet * 753.5 packets/second = 940368 bytes/second
Chapter 8 • Sensor Operation 49