The Problem
The terms “lidar” and “laser scanning” are often used interchangeably, but they refer to different concepts. So what is lidar vs. laser scanning?
Defining the Concepts
Let’s start with the Wikipedia definitions:
Lidar is a method for determining distance by targeting an object or surface with a laser and measuring the time it takes for the reflected light to return to the sensor.
Laser scanning is the controlled deflection of laser beams—whether visible or invisible.
Both lidar and laser scanning can refer to techniques as well as the devices that implement them, commonly called lidar scanners and laser scanners, respectively.
Rectangles and Squares
The distinction is similar to the rectangle vs. square analogy: all squares are rectangles, but not all rectangles are squares.
Likewise, all lidar scanners are laser scanners, but not all laser scanners are lidar scanners. Lidar scanners always use controlled deflection of laser beams to measure range.
Do all laser scanners measure range with lasers? No. Many laser scanners serve different purposes. Examples include:
- Barcode scanners, which deflect a laser across a barcode; a photodetector reads the reflected pattern to extract data.
- Laser engravers, which use high-powered lasers to cut or etch material surfaces.
- Laser printers, which use laser scanners to direct a beam onto a photosensitive drum, creating an electrostatic image that attracts toner and forms the printed content.
How do you think of lidar vs. laser scanning? There are a lot of other connotations associated with these terms, but I consider them to be based on convention rather than definition. Share your thoughts in the comments, please!
For more information about the basics of lidar, visit our Lidar Basics category.
