SHR3DR

FTL Labs’ SHR3DR (Sub-Seafloor High Resolution 3D Reconstruction) is a
hardware and software solution for the automatic detection of problems such as voids forming in the subterranean environments beneath Navy waterfront facilities. It is a tool intended to be used by NAVFAC and commercial site maintenance crews in the assessment of these areas, which are hidden and typically require expensive, destructive, and time-consuming dredging and digging to fully inspect. With SHR3DR, technician-level personnel can quickly and easily collect data for an entire wharf in a wide range of waterfront environments. The SHR3DR software acquires and analyzes seismic data using advanced acoustic signal data processing algorithms and a custom trained neural network, and outputs void locations and problem areas to a user.

FTL developed a proof of concept for the combined hardware technologies, automation process, and software pipeline that were developed and demonstrated. The SHR3DR system includes a custom survey rig with both a portable seismic impulse generator and a hydrophone reel that can be extended into the desired water depth. The entire apparatus can be deployed on an ATV or truck for delivery and ease of movement down the length of a wharf or pier. At regular intervals along the surface, the hydrophone array is lowered into the water, the impulse generator excites acoustic waves, and the signals are sensed and saved. The full signal dataset for a wharf is then imported into the SHR3DR software, which processes the data to reduce noise and highlight important features. The neural network then detects possible voids and calculates information such as pile depths. This data can be registered with a 3D LIDAR surface scan and then presented to the user in an intuitive interface.

The SHR3DR Phase I program’s primary objective has been to develop a proof-of-concept technology for the automatic detection of voids and calculation of pile depths in the subterranean areas below wharfs and piers. SHR3DR utilizes active seismic sensing with specialized algorithmic acoustic signal data processing and a custom trained neural network to meet these objectives, and the resulting survey tool is intended to be used by the Navy for determining whether facility repairs or maintenance are necessary.

The Navy has awarded FTL a Phase II contract to continue R&D on the SHR3DR program, during which the acoustic signal generation and sensing hardware will be built and tested, and a full software application will be developed.