High-Definition Inspection Goes Mobile
Documenting aboveground assets with mobile mapping
A telephone utility company required high-definition imagery to document various elements on telephone poles. Details included guy wires, wire sags, insulators, and snowshoe loops, as well as measurements to show eventual additional space to string more lines. The unique information detailed on a label on each pole was also required for asset identification.
Currently, telephone utility companies send crews to manually survey poles using a handheld GPS unit and a tablet for capturing the images. Since the surveyors spend between 30 and 60 minutes on each one, they are limited to about 10 to 20 poles per day.
Information Gathering Through Images
Founded in 1999, Alabama-based LiDARUSA builds affordable unmanned aerial vehicles (UAV) and mobile-mapping systems using the latest tools for scanning, imaging and navigation. The company identified an opportunity to improve productivity of asset data collection for the telephone utility company using car-based technology. By using its economical mobile-mapping system (MMS) ScanLook, the need for crews with handheld equipment could be removed.
LiDAR USA first tested the LiDAR-based ScanLook Highway Mapper system using a Ladybug 5/5+ 360 camera from FLIR (formerly Point Grey) to capture the imagery from a car. However, the company discovered that the Ladybug did not have enough resolution to zoom in and see all the details its clients required. The speed at which the ScanLook Highway mapper drove was not advantageous for image quality and accuracy.
In addition, the varying distances of the poles from the mobile mapping car could range from just a few feet at the road’s edge to up to 400 feet away, also affecting results. LiDARUSA had searched for a solution to capture images from distances that, in the past, were either too close for focus or too far away to achieve a high enough resolution.
Lighting conditions change drastically on a car, causing a further hurdle, unlike aerial applications pointing toward the ground with the sun behind you. With a car, especially when using a 360° system, it’s likely that each camera will be capturing an image in different lighting conditions — toward the sun or into shadows. Therefore, cameras used need to be able to capture fully lit photos, regardless of the lighting conditions. In short, LiDARUSA needed to add high-quality imagery from industrial-strength cameras.
High-Resolution: The Only Solution
After presenting its utility client with images captured from a variety of cameras, LiDAR USA found that those from Phase One Industrial met its needs, both spatially and radiometrically.
The company purchased four Phase One Industrial 50 megapixel cameras with wide-angle lenses to complete its LiDAR-based ScanLook Highway Mapper system. The system also contained a multiple-laser scanning system, an Inertial Measurement System (IMS), and a 360° camera.
Adding Phase One Industrial cameras extended the systems’ use for solutions that were once virtually impossible when using only high-definition 360°cameras or even more readily available directional cameras.
A combined four-unit camera system was mounted on a vehicle, with one facing forward, slanted right; one facing forward, slanted left; one facing backward, slanted right; and one facing backward, slanted left.
Improved Imagery That Captures Everything
The cameras reliably collected the required high-resolution images needed for the survey. LiDARUSA then processed the data using customized viewing software.
Out of the box, the system worked well, providing all the detail LiDARUSA needed right from the start. There was no trial and error.
The biggest advantage of the 50 MP Phase One Industrial camera is its quality. It is extremely reliable and holds the dynamic depths LiDARUSA was looking for. The dynamic range minimizes shadows for cameras looking down a road. With Phase One Industrial cameras, LiDARUSA can adjust the contrast to make it look like an image is taken in broad daylight when in fact it is shaded. Very few cameras have the ability to provide these results.
Adding the Phase One Industrial cameras enabled LiDARUSA to capture the required details, such as small text on asset identifiers, with high-definition resolution while driving at typical road speeds; acquire accurate images regardless of distance from the car; produce daylight-lit image quality, regardless of poor lighting conditions; and collect 150 miles of field data in a day, as opposed to 10-20 poles checked manually.
With Phase One Industrial cameras, LiDARUSA is able to capture amazing detail from close up or from several hundred feet away. Poles that are right beside the curb, usually too close for the cameras mounted on the car, can now be viewed with perfect clarity. Moreover, poles photographed now appear straighter and not distorted from the super fish-eye lenses that are normally used. This improved imagery appears more normal to the client.
Outstanding high fidelity and resolution are critical qualities in a camera being operated from a moving vehicle. This system’s ability to look forward, backward and to the sides from a distance ensures that LiDARUSA can collect enough images to achieve the results it’s looking for. UP
The Author: Jeff Fagerman is the CEO of LiDARUSA and a licensed surveyor. He is a graduate of Ferris State University and Purdue with a master’s degree from the School of Civil Engineering. He is also a PLS #22408 in Alabama and a Certified Photogrammetrist.