New Techniques for Critical Infrastructure Inspection

Advancements in lidar, SLAM, and AI-driven mapping are transforming how engineers and surveyors capture data in challenging or hazardous environments. This session highlights innovative approaches to infrastructure assessment that reduce on-site risk while improving data accuracy and efficiency. Presentations will cover the use of combined static and mobile lidar techniques to safely capture detailed bridge data without disrupting traffic, the deployment of SLAM-based mobile mapping and unmanned surface vessels for under-bridge and hydrographic surveys, and new methods for performing precise surveys in GNSS-denied environments. The session will also explore how pretrained AI models are being applied to classify and map powerline infrastructure directly from lidar point clouds, supporting asset management and vegetation monitoring. Together, these case studies illustrate how next-generation mapping tools are enabling safer, faster, and more intelligent infrastructure management.

The following presentations will be shared in this session:

AI-Based Powerline Classification and Mapping

Presented by Nejc Dougan, Flai

This session will explore the use of pretrained AI classifiers to support powerline mapping from lidar point clouds. The models are capable of identifying key infrastructure components such as conductors, towers, insulators, shield wires, and guy wires. Building on this classification, the workflow includes vectorization of the detected elements and supports vegetation segmentation for corridor management. The process can be fine-tuned to accommodate different environments or sensor characteristics.
We’ll present a real-world use case involving the continuous mapping of transmission infrastructure with lidar data. Particular focus will be placed on practical deployment, including how the system can be run on-premise to meet strict data security requirements for critical infrastructure. The talk will outline both the capabilities and limitations of the approach, and reflect on lessons learned from real-world applications.

Utilizing Unique Scanning Techniques to Reduce On-site Safety Risk Exposure While Collecting Detailed Bridge Information

Presented by Matt LaLuzerne, McKim & Creed, Inc.

This presentation will discuss the methodologies for utilizing scanning technologies to develop a high-resolution and accurate 3D representation of the Cape Fear Bridge in support of the rehabilitation design. The existing bridge and adjacent roadway does not have safe areas to perform field operations without lane closures. Our team utilized a unique combined approach of static scanning and mobile lidar collection to capture information along the bridge without disrupting traffic. The presentation describes how the team was able to utilize safe areas around the tender house to scan bridge features, while observing survey ground control safely. The scan data was further used to calibrate the mobile lidar collection.This approach minimized disruptions to traffic, significantly reducing project schedules, and maintained design survey accuracies.

Using SLAM for Precise Hydrographic Surveys in GNSS-denied Environments

Presented by Greg Gibson, Woolpert, Inc.

The vast majority of hydrographic surveys are performed using a GNSS-aided inertial navigation system (GNSS/INS) which provides precise time, latitude, longitude, height, pitch, roll, and yaw of the vessel and sensor(s). But what if we need to perform a hydrographic survey in a GNSS-denied environment? Historically, the best solution was to rely on robotic total stations, but that approach has significant limitations with respect to line-of-sight and time synchronization. Point cloud generation using SLAM technology is becoming increasingly common. While some efforts have been made to use SLAM methods with acoustic sensors such as multibeam echosounders, there are limitations involved here as well. Acoustic data tends to have a much lower signal-to-noise ratio than lidar or Imaging sensors along with a wider beam width and therefore lower resolution. Further, most multibeam echosounders are configured in a 2D array (swath) while SLAM methods generally rely on rotating lidar sensors or 360° camera arrays. Instead of using SLAM directly with the acoustic data, our solution was to use a SLAM lidar system on the survey vessel as a navigation device in lieu of GNSS. While the most visible result of a successful SLAM survey is a cohesive point cloud, the relative position and orientation of the lidar sensor is also calculated. By extracting and formatting this position and orientation data to simulate a post-processed trajectory file (i.e. SBET) it can be applied to multibeam or any other sensor on the vessel in an otherwise standard workflow. I will discuss the original concepts and in-house testing we performed to bring this idea to reality and highlight a survey performed at Pier 39 in San Francisco which required high-accuracy multibeam data to be collected underneath an existing pier. We will share the methodology, the results of the survey, and the lessons learned. We’ll also discuss the accuracy and repeatability of the data, the time synchronization considerations, and the applicability of this method to different GNSS-denied environments.

SLAM Boat: Mobile Mapping For Under Bridge & Under Water Infrastructure Inspection

Presented by Ben Williams, Exyn Technologies, and Cody Carlson, Seafloor

With punishing recurring weather events testing the limits on aging infrastructure like our roads and bridges across the United States, civil survey teams will require new tools to quickly assess risk to get critical jobs underway to keep the public safe. Today, exciting advancements in lidar technology and mobile SLAM mapping have unlocked new tools and workflows to help these teams capture accurate, georeferenced 3D models quickly and efficiently. 

In this presentation, we will explain for attendees the current state of hydrographic and land surveying for civil infrastructure management and the technology being used to capture this critical data in the field today. We will cover how advancements in mobile SLAM – including the addition of sensors like the Trimble DA2 – have unlocked comparable levels of accuracy to a traditional laser scanner but captured in a fraction of the time. We will walk attendees through a recent use case using the mobile SLAM platform, Nexys, and an unmanned surface vessel to capture and quickly combine a hydrographic and land survey or a road and river into a complete 3D point cloud for inspection. Throughout our presentation, we’ll highlight the time savings and ease of mobile SLAM mapping for 3D reality capture. Equipped with survey tools like Nexys and advanced unmanned surface vessels, civil survey leaders will be better prepared to safely monitor their aging infrastructure for a fraction of the time and budget. Not to mention inspire a new generation of surveyors by demonstrating these exciting advancements in lidar and SLAM mapping in the field.