Velodyne VLP-32C - Chapter 8: Sensor Operation; 8.1 Firing Sequence; 8.2 Throughput Calculations

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 50
8.2 Throughput Calculations 50
8.2.1 Data Packet Rate 50
8.2.2 Position Packet Rate 51
8.2.3 Total Packet Rate 51
8.2.4 Laser Measurements Per Second 51
8.3 Rotation Speed (RPM) 51
8.3.1 Horizontal Angular (Azimuth) Resolution 51
8.3.2 Rotation Speed Fluctuation and Point Density 52
8.1 Firing Sequence
All 32 lasers are fired and recharged every 55.296 μs. Lasers are fired in pairs. 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 32
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 12 firing cycles in a data packet. 12 x 55.296 μs = 0.663552 ms is the accumulation delay per packet.
1 packet/0.663552 ms = 1507 packets/second
1248 bytes/packet * 1507 packets/second = 1880736 bytes/second
50 VLP-32C User Manual