FAQ
LiDAR vs lidar
Should it be capitalized as “LiDAR” instead of “lidar”?
No! We should use the lowercase because it’s a commonly used word just like radar. When radar was some sort of highly exotic military technology, it made sense to use all caps for the acronym “radio detection and ranging”, but by now it is so common that we should use lowercase. Many other words started out capitalized when new and exotic, but became lowercase once commonplace:
- laser, Light Amplification by Stimulated Emission of Radiation
- scuba, Self-Contained Underwater Breathing Apparatus
- taser, Thomas A. Swift’s Electric Rifle
Now that most phones and some cars are equipped with lidar, it’s a good time to just use lowercase. Perhaps the main barrier to doing so is Apple’s autocorrect.
Are rectangular lidars solid state?
No, not necessarily. Whether or not something is solid state is based on whether it has macroscopic moving parts in it, not based on its shape.
Livox lidars are often mistakenly assumed to be solid state, but they are in fact mechanically scanning with some using Risley prisms and some using mirrors.
Likewise, Luminar lidars are often assumed to be solid state, but they are not. The Luminar Hydra uses galvos and the Luminar Iris uses polygonal mirrors.
Solid state lidars are often perceived to be more durable and reliable. Lidar manufacturers have taken note of this market bias in customers, and marketed accordingly. For example, the Velodyne HDL-64 was marketed as solid state (even though it is externally spinning) in their 2016 press release announcing the VLP-32A:
Based on his experience during this challenge, Hall recognized the limitations of stereovision and developed the HDL-64 Solid-State Hybrid LiDAR sensor.
As justification, however, one might consider that it has an array of 64 lasers to distinguish vertical bearing, so perhaps it could be called 50% solid state as mechanical scanning is used only for the horizontal direction! In contrast, Luminar and Livox lidars use mechanical scanning for both directions, despite being a single non-spinning box.
