3D Scanning: Better Data, Accuracy, and Analysis
This article was written by Alex D’Amico as part of an internship project to re-investigate 3D scanning technology to evaluate situations where it can improve data collection for broadband deployment. Reach out with any questions at firstname.lastname@example.org! A terrestrial 3D scanner is a tool that utilizes lidar technology to measure distances from the scanner to objects in its environment around it. Unlike most other types of 3D scanners, terrestrial scanners are used in larger environments and are typically used to scan buildings in construction projects and survey land. Katapult has done research and testing to implement this technology for data capturing in the field, specifically in instances where traditional methods of data collection are difficult to utilize.
There were several constraints were taken into account when testing different models of terrestrial 3D scanners:
Range- In order for a scanner to be useful in the field, it must be able to scan at or above 150 feet (45 meters) away from the scanner.
Accuracy- In addition to range, scans must be able to provide the same or better accuracy than a client would expect from traditional scanning methods (<1.5 inches or 35 millimeters). 3D scanners use the time of flight form of measurement, utilizing the time it takes for a laser to reflect off of an object to measure its distance. Darker objects, such as wires, are more difficult for a 3D scanner to process due to their lower reflectivity, making accuracy more difficult than higher-reflective objects.
Price- 3D scanners can cost between $20,000-$120,000, so it is important to account for the economic viability of implementing this technology.
Usability- Field workers need to be able to collect data quickly and efficiently. Choosing a scanner that requires little setup time and effort is essential for proper implementation.
Scanners that were considered viable options were either rented for testing or sample scans were sent from a retailer to match our testing parameters. Scanners were tested for range, scan time, accuracy, and practical applicability to understand if they were capable of providing data needed to use for our services. Below are the scanners and their results in testing.
Leica BLK360 (tested at Katapult)
Price- $19,000 (new)
The Leica BLK360 is the company’s most budget-friendly, traditional terrestrial 3D scanner. At a price of $19,000, the scanner undercuts its most direct competition in cost by several thousands of dollars at minimum. The maximum range of the scanner is 60 meters with an accuracy of 4mm @ 10m, 8mm @ 20m, progressing on a linear scale. The scanner can be connected to an iPad Pro for scanning but is not required to do so. All scans must run through Leica’s proprietary software, Register360, before being exported.
Portability and Setup
The BLK360 scanner is 6 inches tall and 4 inches in diameter, making it one of the smaller scanners in the segment. The third party case that I used weighed around 50 pounds and included a tripod, adapters, chargers, and batteries, and it had both a carrying handle and wheels. The tripod was easy to use, and the BLK360 connected to it effortlessly. This process was simple and quick and would require little training for a worker to understand.
Ease of Use
To turn on the scanner, simply hold the button on the front of the device until the ring around the bottom lights up. The device auto calibrates, and the ring illuminates green when the device is ready to scan. To start a scan, press the same button, and the scan will begin. When the ring turns solid green again, that scan is complete, and it is ready to begin another scan. This process was quick and easy, requiring very little thought or effort to perform. To transfer the data from the scanner, the device must either have a wifi connection to the workstation, an iPad Pro, or a USB-C to ethernet connection to the workstation. Using the wired connection proved to be easy and effective, as the files transferred to the workstation quickly. Leica’s Register360 was somewhat intuitive, but I had difficulties seeing the full scans rather than slices of them, and I could not get several scans to register together from about 70 feet apart from each other. Register360, a software that is required for all Leica scans to go into first, requires training for users to use effectively.
Range and Practical Application
The maximum advertised range of the BLK360 is 60 meters. The most usable data came within a 40-45 meter range, as larger objects, such as the electrical poles, were tracked by the scanner moderately well at some distance. However, it had difficulty detecting wires at all anywhere above 30 meters. The battery life of the device is advertised to last for at least 40 scans on a full charge. While I only made a total of 7 scans, battery life was no issue during my period of use.
Below are pictures of the scans from different locations:
Image 1: side view of scan, taken from sidewalk adjacent to Old York Road. Distance measured comes from the wires to the base of the scanner.
Image 2: Side view of a scan with measurement taken from the furthest point of a powerline to the bottom of the scanner.
Image 3: top view of a scan with the maximum distance from the scanner measured with best resolution.
Image 4: Top view of 3 cloud points with “ghost connections” (dashed lines) lined up with overlay. Attempts to register these clouds failed.
The Leica BLK360 is a capable piece of equipment for the price point, and the device itself is easy to use. With scan times of about 3 minutes and 30 seconds, the BLK360 does not require large amounts of idle time for workers when running the device. However, Leica’s Register360 software requires training and is not as intuitive as it might immediately seem, and its limited range, especially when detecting wires, makes the BLK360 a nearly unusable product for the purposes of Katapult. While its low price, small size, and usability make it appealing, its limited capabilities do not allow the BLK360 to be a viable option for scanning electrical poles and wires at distance.
Faro Focus S70 (tested at Katapult)
Price- $25,000 (used) *These results were also used to analyze the Faro Focus M70, an older Faro model.
Overview The Faro Focus S70 is the company’s shortest range scanner of the Focus product family with a range of up to 70 meters. This used piece of equipment costs $25,000. Accuracy for the S70 is 2mm @ 10m, and 3.5mm @ 25m. However, range is limited to just 50 meters for dark objects (2% reflectivity). The scanner can be connected to a laptop, but is not required to be connected to any hardware while scanning, and it includes a touch screen display for scan settings. All scans must be processed through Faro SCENE before being exported.
Portability and Setup
The Focus S70 is a typical size for the product class, and it weighs about 10 pounds. While on the tripod, the total weight of the system was about 25 pounds, which proved to become mildly heavy if walking longer distances. Setup was simple, and the scanner intuitively connected to the tripod by loosening a screw, placing the scanner on the top of the tripod, and tightening the screw to secure.
Ease of use
The scanner has a touch screen embedded into the side, which can be utilized for scan settings, file organization, profile making, and for scanner operation. Scans can be adjusted for both resolution and quality, and adjusting these settings affects the scan time, which is estimated in real time. Scan times can range from 2 minutes to 2 hours, depending on the settings applied. With some training on where to find certain settings and how to navigate menus, the software was intuitive to use. However, the screen was difficult to see in direct sunlight due to a significant glare.
Using the scan menus and creating project folders was intuitive but took some time to prepare for going out in the field. While it is not necessary to create these folders to begin scans, they help considerably with file organization, especially if you are taking multiple scans at different locations.
The Faro Scene desktop software is very user friendly. When an SD card is connected to the computer while Scene is running, it will automatically prompt the user to download the files from it. The user interface is logical and straightforward. However, when all scans in a folder are processed and registered, they all appear on top of each other by default, which might not be immediately apparent. Toggling the visibility to off for every scan except one fixes this.
Range and Practical Application
The advertised maximum range for the Focus S70 is 70 meters. The maximum range of the scanner depends heavily on the resolution of the scan. For example, a scan with ½ resolution will produce far better detail than a scan even at ¼ or ⅕ resolution, especially from far away. In Katapult’s application, wires that were visible using the ½ resolution were faint or did not appear at all in lower resolutions.
The advertised maximum battery life is 4.5 hours. The battery percentage is displayed on the scanner in the top right corner. During the tests, the scanner went from 100% to 74% over a period of over an hour of scanning, proving the maximum battery life to be accurate. Higher resolution and higher quality require longer scan times, below is a table depicting the amount of time each resolution requires, isolated to only resolutions with adequate accuracy for the needs of Katapult (1.5 inch accuracy at 150 feet away). All scans include picture capturing, exposure metering, color capturing, and inclinometer scans, which account for about 2 minutes and 30 seconds of each scan time. Higher qualities take a larger number of scan passes, and higher resolution causes the scanner to rotate more slowly as it is scanning.
Detailed below are pictures of the scans in Faro Scene software.
Image 1: Overview of a single scan (½ resolution, 2x quality) showing the maximum scanning distance and the detail of the poles and wires.
Image 2: Overview of a bundle of 3 scans taken along the roadway. Total viewing distance is about 180 meters. ½ resolution, 2x quality.
Image 3: Cropped scan depicting the results of a ½ resolution, 2x quality scan at far distance.
Image 4: Cropped scan depicting the results of a ¼ resolution, 2x quality scan at far distance.
Image 5: Cropped scan depicting the results of a ⅕ resolution, 2x quality scan at far distance.
Image 6: Single scan taken at a baseball field to test quality and range. Distance shown is 67.44 meters. ½ resolution, 2x quality.
The Faro Focus S70 is a powerful scanner that is easy to use and provides adequate results when scanning poles and wires. Scan times are reasonable even at higher resolutions, and the Faro Scene software is capable and easy to use. While $25,000 is one of the more expensive pieces of equipment being tested, it is a worthy product for scanning poles and wires with good range and accuracy.
The Faro Focus M70 model has about 1/3rd the maximum resolution as the S70. Given that the near-highest resolution was required to provide an adequate scan of poles and wires at distance, it can be concluded that the M70 will not provide results that would be usable for our purposes.
Trimble TX8 (tested at Katapult)
Price- $10,000 (used)
The Trimble TX8 is one of the company’s older terrestrial 3D scanner models, dating back to 2016. It has a range of up to 120 meters with an accuracy of 5.7mm @ 30m. This used piece of equipment costs $10,000. The scanner is designed to be able to operate independently from other hardware, although hardware accessories are available. Data is saved to a USB flash drive. All scans must be processed through Trimble’s RealWorks software before being exported.
Portability and Setup
The TX8 is one of the larger and heavier scanners, weighing about 25 pounds. The total package weight of the system and all its components was 70 pounds, making this system cumbersome to travel with. Additionally, a surveying tripod had to be used because of the scanner’s size and weight, which is bulkier and heavier than the tripods competitors use. Aside from size and weight, setup is relatively simple, as a screw holds the scanner to the tripod. Batteries are inserted into a slot and can be easily replaced and recharged, and a USB flash drive is the device used for data storage, which is simply inserted into a USB port before powering on the device.
Ease of use
The TX8 has a screen embedded into the machine, which is the primary interface for file savings, settings, and starting scans. This system is easy to maneuver, and the scan “levels”, which change the scan times and accuracy, are intuitive. The scanner does not have an auto-leveling tool, but the user can adjust the scanner to level using mechanical knobs. This must be done every time the scanner is moved. In direct sunlight, the screen can be difficult to see, which is a common trait of these devices. The battery life was sufficient, but not outstanding, as the level reached near empty after about 90 minutes of use. Thankfully, batteries can easily be swapped, so long as there are extras available on hand. Moving the device can be difficult, as the system is heavy. The carrying case for the scanner comes with wheels, though, and can be maneuvered like a suitcase.
Range and Practical Application
The advertised maximum range of the TX8 is 120 meters, and the scanner performed this figure almost exactly on the Level 3, 10 minute scan. The TX8’s accuracy near its maximum range is impressive, as it picked up wires up to its maximum range with good clarity and accuracy. The 2 hour battery life appeared to be accurate, and having 4 batteries in total allows for enough power to last through a work day.
Below is the advertised accuracy and scan times for the TX8:
In theory, at these accuracies, a Level 1 scan gives sufficient accuracy up to 30 meters away, a Level 2 scan scans up to 90 meters away, and a Level 3 scan can collect data up to 120 meters away. Scanner accuracy and distance can be seen in the results section below.
Image 1: scan with a measurement showing the maximum distance of a point detected (119.32 meters)
Image 2: scan taken at Level 1, 2 minute scan
Image 3: scan taken at Level 2, 3 minute scan
Image 4: scan taken at Level 3, 10 minute scan
Image 5: scan depicting the short and long-range capabilities of the scanner
The Trimble TX8 proved to be a capable scanner with accurate scans even at its maximum range. However, the device is large and heavy, and it does not have some of the features newer scanners have, including auto-leveling and an optical camera. For the purpose of scanning electrical poles, the device is more than sufficient, and at $10,000, the TX8 is the best value of all the scanners tested.
Artec Ray (tested by 3rd party)
Price- $60,000 (new)
Overview and Analysis
The Artec Ray is Artec’s only terrestrial 3D scanner. The price for this product is $60,000 new. It has a range of 110 meters in its High Sensitivity mode, and it can be controlled remotely through a laptop, iPad, and any other tablet. The scanner weighs about 10 pounds, making it average sized for the product class. The accuracy of the Ray is 0.25mm @ 15m. Scans must go through the Artec Studio software, and scans from the Ray can be combined with any of Artec’s other scanners through the software.
The Artec was only able to acquire data on wires from about 35 meters away. While Artec Studio is a powerful software that has some capabilities other software does not have, the price for this scanner and its limited range of capabilities make it an unfeasible option for Katapult’s purposes.