- Chase Comeaux
LiDAR On and Around Bridges
Updated: Feb 6
SurvTech was called to capture data on, around, and below Centennial Bridge in Leavenworth, Kansas. While considering such a project, a 3.5-mile corridor straddling two states, its multiple points of interest, and a variety of obstacles to overcome, we needed to deploy various technologies to capture the information necessary to complete the task. Implementing strategic planning, careful execution, and robust processing methods, SurvTech was able to be successful in providing valuable data to our client.
To obtain a complete picture of the environment, we utilized four unique data collection platforms on many vehicles to cover the entire area of interest. In order to minimize the possibility of features changing while maximizing coverage of valid data, collection of each phase was accomplished and verified as close together in time as possible. We also needed to consider the level of water that was involved.
First, the staple was to obtain conventionally surveyed coordinates to control and check the remotely sensed data. We used vertical and horizontal checkpoints on hard flat surfaces and painted targets to ensure data accuracy and real-world positions. Next, we implemented remote technologies. A Riegl VUX-1UAV mounted to a Harris-H6 Hybrid UAS was flown to provide dense, topographic information across the site. The road corridor running through the project and crossing over Centennial Bridge itself needed highly detailed and accurate information to extract desired feature data along the travel path. The same Riegl VUX-1UAV was detached from its UAV carrier, locked into a custom Mobile scanning fixture, and mounted to a SurvTech crew truck. After loading the planned settings into the VUX, the crew drove the corridor at optimized speeds to collect the Mobile LiDAR phase data. Aerial imagery, which invaluably enhances the information that can be perceived in a LiDAR point cloud, was captured with a DJI Phantom 4 Pro, one of SurvTech’s capable imagery platforms.
At this point, we’ve only gotten data on and around the bridge. We still need information underneath it. This was when we inserted Bub, our 25’ aluminum vessel that we used to carry a Norbit iWBMS multi-beam sonar scanner to collect hydrographic data. Now that all data is collected, processing begins. Using the survey control, tailored workflows, and some critical thinking, our team, could process all phases of data individually and create a homogenous working dataset over the entire area of interest. Once validated for data quality within each phase, the extraction of desired information and product generation can begin.
At SurvTech, we are not limited to any single technology or what it can accomplish. We’re certainly not determined by what has or hasn’t been done before. We continue to be creative and innovative in how we maximize the plethora of equipment and technology available to us and have demonstrated many times now that if the proper procedures are followed from planning to products, useful data can be had, even when we find ourselves in unexplored territory.