How do 3D scanners work?

3D laser scanners use light detection and ranging (LiDAR) technology to send out high-speed light pulses. These pulses reflect off of surfaces and objects and return to the scanner’s sensor. The scanner calculates the distance between the object and the scanner based on the time elapsed between emission and return of the light pulse. That number is then converted to a pixel coordinate, with XYZ coordinates. 

This process happens incredibly fast. A 3D laser scanner may send out anywhere from 200,000 to 1 million pulses per second. All that data is processed and aggregated into what is called a point cloud, a point-based 3D representation of the object or area being scanned.

Learn more about point clouds here > 

3D laser scanners are available in both stationary and handheld versions, both of which offer different advantages.

Handheld 3D Scanners vs. Stationary 3D Scanners: What’s the difference?

A stationary 3D scanner is usually mounted to a tripod or arm and placed on a level surface. Stationary scanners don’t move during operation; rather, the object being scanned is rotated, so the scanner can read all sides.

A handheld 3D scanner is either held by the operator or mounted to a backpack or pole. Handheld scanners are carried around a space or object, capturing data as they go. 

There are two primary advantages to a stationary 3D scanner. The first is efficiency. Stationary scanners are very convenient for scanning a lot of objects in a row, such as historical artifacts. The second is accuracy. Stationary 3D scanners offer truly unparalleled accuracy and resolution, generating extremely dense, highly precise point clouds. However, it’s worth noting that this level of precision is not necessary in many cases.

Handheld 3D scanners are fully portable and generally more convenient for field-based applications. Unlike stationary scanners, which require a desktop or laptop computer (and, consequently, an outlet), a handheld scanner can run off a phone, which is much more manageable in the field. Handheld scanners are great for scanning hard-to-reach areas and spaces that don’t offer any flat surfaces. Plus, handheld scanners require almost no training to use, making them a more accessible choice.

While handheld 3D scanners don’t offer quite the same level of precision as a stationary scanner, it’s important to note that handheld scanners are still highly accurate, usually beyond what is required for a given application, and are more than sufficient for many purposes and industries. 

Handheld 3D laser scanners are not the only option on the market for bringing LiDAR technology into the field.  A common alternative is drones.

3D Laser Scanners vs. LiDAR Drones

3D laser scanners share many capabilities with drones equipped with LiDAR sensors. Both tools send out light pulses and collect data that can be processed into highly accurate 3D models. However, the two are not necessarily interchangeable.

Many companies use drones to survey stockpiles, large buildings, swathes of land, and other assets and capture GPS data to create digital renderings. Drones can cover massive territories in a short period of time, including rough terrain and areas of land that are difficult to access by other means. Needless to say, a handheld scanner would be extremely inefficient for projects of scale.

However, operating a drone indoors or under any sort of covering can be difficult and even unsafe. Drones are not as practical as handheld 3D scanners for scanning smaller spaces or objects. And while drones can capture extremely accurate data, they only capture data from above, whereas a handheld scanner can be carried, for example, all the way around a stockpile or object.

Drones and 3D scanners both offer considerable advantages, depending on the application. Choosing the right tool for you will depend heavily on your needs and the limitations of your project.

Which 3D scanner should I buy?

A handheld 3D scanner, a stationary 3D scanner, and a drone each offer different advantages, and the best choice for you will depend heavily on your needs.

You can compare two of our favorite handheld scanners here and see our drone offerings here.

Our sister company, Event 38 Unmanned Systems, is a leading manufacturer of American-made drones well suited to large-scale LiDAR scanning and surveying products.