Underwater GPS being used to reconstruct 3D photogrammetry models.
Reprocessing old data to yield new results. Lessons learned from police forensic requirements applied to the SS Gwladmena.
Discussion around the use and benefits of accurate GPS values with image alignment in photogrammetry
Slope Analysis As we have discussed before Digital Elevation Models help us understand subtle changes in depth (or height) of the subject. We also think they are art in their own right. Tucked away in the 1.4 release of Agisoft Photoscan Pro is a preference that adds slope analysis. The colours applied to the model Read more about DEMS – Another View[…]
Gone Late last week a tanker in Weymouth Bay managed to snag a torpedo on its anchor. Royal Navy divers from the Southern Diving Unit dealt with the problem torpedo and a link to the full story is here. The torpedo in question is almost certainly one of Grahame Knott’s Deeper Dorset finds. The torpedo Read more about Gone But Not Forgotten.[…]
Background Way back 2011 Grahame Knott of Deeper Dorset found a small wreck site in Weymouth Bay. At the time the search was on to find more of the P47-D Thunderbolt but in true shipwreck hunting fashion Grahame found another mystery. Known as the Brandy Wreck, the site had four iron guns, two anchors, a millstone and ballast stones. Read more about The Brandy Wreck – Then and Now[…]
Background A few years back Grahame Knott of Deeper Dorset found the dispersed remains of an aircraft in Weymouth Bay. Over the years pieces of the jigsaw have come together, with pieces of information as diverse as component part numbers and an entry in the Portland War Diary (Held at the National Archives) all adding up to Read more about Bolt in the Bay – P47-D Crash Site[…]
The Project The SS Thistlegorm is rated a world class wreck dive. But only a tiny fraction of the world can don SCUBA and pay the wreck a visit, so the Universities of Nottingham, Ain Shams and Alexandria have collaborated to digitally record the heritage beneath the waves. Funding for this work has been provided by Read more about Project Thistlegorm – The Processing Begins[…]
The Art of DEM For some reason, I am drawn to Digital Elevation Models (DEM). They express so much information in such an elegant way. Their creation does require embedding GPS data, but thats almost a given these days as its a straightforward exercise pulling points out of sonar. In simple terms, a DEM is Read more about The Art of DEM[…]
Earlier this week Kevin Heath of Sula Diving kindly towed his side scan sonar fish past the remains of the UB 116, generating a very clear image of the wreck site: Relating the Model to the Planet With the GPS positions recorded in the sonar we can now extract a few key points and add them to Read more about Geo Referencing the UB 116[…]