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Arthur T Knackerbracket has processed the following story:
In 1918, the steam-powered SS Mesaba sank in the Irish Sea after being hit by a torpedo from a German submarine during World War I. The ship might have been forgotten, except that it had ties to the infamous Titanic disaster of 1912. On Tuesday, Bangor University announced that the shipwreck of the Mesaba has been located.
Mesaba was a merchant vessel traveling in the same waters as the Titanic. According to the Encyclopedia Titanica, a repository of Titanic research, the Mesaba sent the large passenger ship a radio message cautioning of heavy pack ice and a great number of large icebergs. The message, however, was never relayed to the Titanic's bridge. The Titanic struck an iceberg and sank later that evening, in a disaster that claimed more than 1,500 lives.
The research team found the Mesaba among 273 shipwrecks scattered across 7,500 square miles (19,400 square kilometers) of the sea. The researchers used an advanced seafloor mapping technology called multibeam sonar and combined the results with historical records and maritime archives to identify the merchant ship's final resting place. A dramatic sonar image shows the Mesaba split into two main parts.
(Score: 4, Insightful) by janrinok on Sunday October 02 2022, @06:17PM (5 children)
During the 1970s and 80s I viewed quite a few sonar 'images' of underwater objects. None of them really showed any significant detail other than the existence or absence of something.
Looking at the images in this story shows how much technology has advanced in that 50 years, but even these images are coarse compared with some that I saw about a decade ago, also from a research vessel. Digital signal processing made much of this possible and improved hydrophonics too, of course. The modern sonobuoys have incredible beam-shaping properties and the multi-beam sonar that was used in these discoveries was, until not very long ago, little more than a dream.
(Score: 2) by RS3 on Sunday October 02 2022, @08:09PM (4 children)
Yes, we've come a long way. A friend of mine works R&D at an acoustic transducer company. He probably divulges more details than he should, but it's amazing what they're doing in just the transducers, including various sound wave shaping, lensing, filtering, etc., all done with various materials and their sonic characteristics such as propagation speeds. Also the carrier frequencies have increased several magnitudes. 40KHz used to be typical, but now they're doing 50MHz and above. I had to think about 50MHz as being "sound".
So incredible transducer advancements, then put into phased arrays [hackaday.com] and as you mentioned huge advancements in digital signal processing- both hardware and software / algorithms.
(Score: 2) by Username on Monday October 03 2022, @09:48AM (3 children)
Yeah, the image looks too good to me, like they scanned, then sent the results through some 3d modeling software. When I look at sonar images, it's just a bunch of colored lines that make no sense. This sonar image makes sense, so I have to think that it isn't a real sonar image.
(Score: 2) by RS3 on Monday October 03 2022, @04:43PM (2 children)
By "colored lines", do they look like these: https://en.wikipedia.org/wiki/Spectrogram [wikipedia.org]
or in 3D, like these: https://en.wikipedia.org/wiki/Waterfall_plot [wikipedia.org]
The 2D plots use color to show the 3rd axis variable's amplitude.
My problem, and possibly for many people, is there's no absolute standard that correlates color to amplitude.
A great example is weather radar- different people render using different color schemes. Many times I prefer shades of gray rather than confusing color scales.
The real 3D images are real. Signal processing systems have been able to create true 3D images from sonar, radar, and other scanning technologies. What I find strange is the medical world often still uses the older sonogram displays for ultrasound diagnostic scans. But often, especially when looking at fetuses they use the true 3D imaging systems.
(Score: 3, Funny) by Username on Monday October 03 2022, @08:02PM (1 child)
Yeah, I'd call those sonar images. I have no idea what I'm looking at.
This is the point where Cypher will tell Neo, "There is too much information in the matrix to decode. You get used to it. I don't even see the code, all I see is blond, brunette, redhead"
(Score: 2) by RS3 on Monday October 03 2022, @08:26PM
So you're saying we need to use "blond, brunette, redhead" for false color rendering [wikipedia.org]. Well alright alright alright.