Using drones to inspect industrial structures is becoming a trend, not just due to the method’s low cost and efficiency, but also because of the lower risk incurred when compared to traditional inspection methods.
One monopole telecommunication tower on Vashon Island in Washington state is deemed un-climbable by a contracted tower crew, due to structural limitations.
In order for engineers to identify, analyze, and design a new antenna mount for the tower, a well known telecommunications company requested that Ryka UAS, a professional drone service company from Seattle, survey the tower and create a high-definition 3D point cloud of it.
In order to closely map this unclimbable tower, a professional quadcopter drone from Turbo Ace was used. The Matrix-E has a Sony A6000 camera and compatible Geo-Snap system from Field Of View LLC (a camera add-on which uses the onboard GPS/IMU to provide a stand-alone geotagging and triggering solution), and acquired 24.3-megapixel images with good geolocation quality.
Electromagnetic wave interference can be a challenge for operating near communication sites, but thanks to an experienced drone pilot, the team was able to fly close to the tower, capturing images with over 80% of overlap and getting a high ground sampling distance of 0.2 centimeters.
Roughly 400 images were taken, which provide detailed information of the antenna and the mount for inventory purposes.
It took less than a day to acquire the images and process them into a precise, dense 3D point cloud which focuses on the upper rad center mounts, wireless-panel style antennas, and associated mounts. The project engineer measured the mount brackets using the high-resolution images in combination with the LAS point cloud.
Pix4Dmapper outputs can then be seamlessly integrated with CAD software for final analysis. Within 2 to 3 days, Ryka UAS delivered final analysis results in CAD to its client.