LIDAR does NOT rely on what for obtaining speed measurements?

The correct choice indicates that LIDAR does not rely on specific reference points to obtain speed measurements. LIDAR technology functions by emitting laser pulses and measuring the time it takes for those pulses to return after bouncing off an object. This allows it to calculate distances and, subsequently, speed based on changes in position over time.

In contrast to specific reference points, LIDAR systems can operate effectively in various environments and do not require pre-defined points to measure speeds. Instead, they can calculate the speed of moving objects without needing to establish fixed coordinates or specific benchmarks.

The role of fixed coordinates, environmental conditions, and GPS data in LIDAR functioning is significant. Fixed coordinates may help in setting up the equipment or for understanding the broader context of the measurements, while environmental conditions can affect the accuracy and effectiveness of the laser signals. GPS data can also be used in conjunction with LIDAR for applications needing positional accuracy, but it is not intrinsic to the basic speed measurement capabilities of the technology.