How does phase-shift LiDAR differ from time-of-flight LiDAR?

Both phase-shift #LiDAR and time-of-flight (ToF) LiDAR measure distance by analyzing how long it takes light to travel to an object and back, but they use different approaches to get that measurement.

Time-of-Flight LiDAR directly measures the travel time of a laser pulse. The sensor fires short bursts of light, then calculates distance by multiplying the speed of light with the round-trip time. It’s straightforward, works over long ranges (hundreds of meters to kilometers), and is common in automotive LiDAR, drones, and topographic mapping. However, its precision depends on very fast timing electronics, so while it’s great for range, it can have slightly lower accuracy (typically centimeters).

Phase-Shift LiDAR, on the other hand, uses a continuous laser beam that’s modulated with a sinusoidal signal. Instead of measuring the absolute time delay, it compares the phase shift between the emitted and received waves. This method gives much finer resolution, sub-millimeter to millimeter accuracy, making it ideal for applications like surveying, plant documentation, and industrial metrology. The trade-off is range: phase-shift LiDARs usually max out at ~100–200 meters, and they tend to be more affected by ambient light and require more power.

In short: ToF = longer range, less accuracy; Phase-shift = shorter range, higher accuracy.