Advanced sonar technology captures the USS 'Monitor' in unprecedented detail
In collaboration with the National Oceanic and Atmospheric Administration (NOAA), Northrop Grumman has released never-before-seen images of the historic USS Monitor, a Civil War-era vessel that sank on 31 December 1862. The images were captured using Northrop Grumman's highly advanced µSAS sonar technology.
The collaboration took place in September 2025, as part of Northrop Grumman's Technology for Conservation initiative. Together, the two organizations scanned the historic ocean-floor site, capturing detailed shipwreck imagery and gaining new insights into the current health of the sanctuary.
Having first been discovered in 1973, the wreck was designated as the United States' first National Marine Sanctuary by NOAA two years later. It rests 73m below the ocean's surface. NOAA, which monitors the health of the sanctuary on an ongoing basis, had been searching for readily available technology capable of evaluating the site in greater detail. Northrop Grumman's µSAS technology, short for micro synthetic aperture sonar and pronounced 'micro-SAS', proved to be exactly the tool for the job.
High-resolution 3D models
Using acoustics, the high-performance sonar solution produced the highest-resolution images of the USS Monitor wreck ever captured, delivering a remarkably detailed picture of the seafloor. The Northrop Grumman team went a step further, creating 3D digital and physical models for NOAA that trace the Monitor's journey from its launch in 1862, through its sinking and subsequent major recoveries, to its current status as a protected national marine sanctuary.
Kevin Gallagher, sonar architect on the µSAS team at Northrop Grumman, commented: “Our advanced µSAS sensor technology gives us a clear, detailed look at the USS Monitor for the first time since 1862 – capturing the ship's hull, interior, and surrounding debris through murky water. This breakthrough shows how Northrop Grumman's leadership in cutting-edge sensing expands what's possible, not just in aerospace and defense, but in exploring and preserving history.”
“Public-private partnerships like the one with Northrop Grumman help support NOAA's role as steward of the USS Monitor's historic legacy and as a testbed for new technologies,” said John Armor, director of NOAA's Office of National Marine Sanctuaries. “The Monitor was a technological marvel of its day, and it continues to serve the nation today by showcasing new technologies, scientific innovations and groundbreaking educational programmes. Thanks to Northrop Grumman's advanced scanning and digital reconstruction capabilities, the public will now be able to view images of the Monitor with near-photographic resolution and extreme three-dimensional accuracy. These products provide a valuable baseline for future monitoring and will inspire the next generation of marine scientists and archaeologists alike.”
