ASI Group

Remote Inspections and the Evolution of Technology

3D image of rock in tunnel

The emerging technology used for today’s inspections

At ASI we enjoy sharing images and announcements about new technology. This includes showcasing our fleet of Remotely Operated Vehicles (ROVs) and Autonomous Underwater Vehicles (AUVs), especially in action performing remote inspections out in the real world. ROVs aren’t only cool and exciting, they are an important tool used to deploy the technology we use for data collection. When it comes to completing an inspection of your underwater asset, a condition assessment is only as good as the data it contains.  Remote inspection technology applies to both the method of collecting data, as well as the platform used to deploy it.

Remote Inspection Technology

ASI uses customizable ROVs with varying penetration distances, some small enough to fit through a standard manhole access (about the size of carry-on luggage). Large ROVs can travel as far as 14 km (or more) via tether, all the while relaying information in real time to the ROV operator and team of technicians. AUVs also range in size and distances, but as they are untethered, they are limited by battery life. These platforms can be equipped with the latest technologies and tools.

High-definition (HD) and standard-definition (SD) digital video

HD and SD cameras capture live video and video stills both above and below the water line. When used during an inspection, the video is viewed in real-time and is recorded onto a data recording computer. ASI also utilizes a 360-degree camera/video array to collect visual data and allow for virtual walk throughs in dry and confined space environments.  

One or Two Multi-beam Sonars

Two-dimensional (2D) and three-dimensional (3D) multi-beam imaging sonar provides valuable feature detection capabilities for the inspection of variances in surface texture.

Profiling Sonar Mounted on a Remote Platfor (left) & Sample Profile Scan (right) - ASI Group
Profiling sonar mounted on a remote platfor (left) and sample profile scan (right)
 Processed 3D Tunnel Multi-beam Data - ASI Group
Example of processed 3D tunnel multi-beam data
Side-scan Sonar

A side-scan sonar (SSS system) can be mounted on any vessel, custom-designed frame, or ROV. The resulting processed sonar imagery results in a mosaic of the full face of the dam structure.


For above and below water inspections, WireScan uses laser for high precision measurements that can be combined with 3D data, resulting in high point density georeferenced data capable of accuracy in sub-millimeters.

Ultrasonic (UT)

ASI has various ultrasonic gauges used to accurately measure metal thickness through coating and corrosion. ASI, has also partnered with a specialist concrete testing company to develop an underwater ultrasonic concrete testing array that can provide the mechanical characteristics of concrete.

Hydraulic Saw (Cellula Robotics)

Cellula Robotics designed and built a hydraulic saw to the specifications outlined by ASI. This saw can be lowered by crane in up to 800 feet of water and has been used to gain access to inspect and survey low-level outlets, intakes and penstocks.


LiDAR (Light Detection and Ranging) scanner collects three-dimensional (3D) point cloud data above and below the water’s surface.

Light Detection and Ranging(LiDAR) - ASI Group
Example: Lidar-Bathymetry

As remote inspection technology advances and becomes easier to obtain, the choice of platforms will continue to evolve. For instance, ASI has utilized aerial drones for out of water areas during inspections and is exploring the use of walking robots and advanced autonomous underwater vehicles.

There are many emerging and currently used technologies for sensor deployment and sensors for data collection. Choosing the right technology and deploying it to collect the information that is needed, means tailoring the inspection platforms with the sensors best suited to collect the necessary data. Each assessment must be able to provide the client all the information needed to make an informed decision about the condition of their asset.

If you want to learn more about how to determine the best technology to use for your inspection, contact us today.