02-06-2016, 01:42 PM
Greets everyone!
LabratSR from Twitter here. Just stopping by to say hi and thank you guys for the great work you are doing.
I have been particularly transfixed by the AQON posted above. The selection of Fugro was always a puzzle to me, however, I am certainly no expert in such things.
I sent the AQON to a guy (thommo101) that rarely posts on Reddit but is a sonar and sub sea systems guy that even worked on a quote for a company that planned on bidding for the search contract.
He posted his comments in this thread.
https://www.reddit.com/r/MH370/comments/...use_furgo/
"Whilst I'm not an expert at sonar imaging, reading through the the tender response to the shortlisted tenderers (PDF page 55 on) it all makes sense.
The Svitzer Salvage proposal has a few negatives, use of low frequency SSS (unsure how they could meet resolution requirements when proposing use of large swaths), and the chosen vessel types which would be slow to transit and noisy.
The Phoenix tender looks pretty good, but synthetic aperture sonars are not yet as trusted due to their increased complexity and reliance on accurate inertial reference units. When they work, they work well. When they don't...
Fugro, well, they have some very nice ships dedicated to this type of work, which were available (also a plus for the tender). Using conventional proven sensors and survey techniques. I understand why they were picked. I'm pretty sure that James Fisher (who contacted us early on in the tender process for advice) ended up not bidding because they thought Fugro would be a shoe-in."
Further, I found this quote from the AQON to be on point and interesting.
"The vehicles (both deep tow and autonomous underwater vehicle or AUV) currently used in the search by Fugro Survey Pty Ltd (Fugro) use an independent sonar instrument to cover the nadir area (a multi-beam echo sounder) whereas other systems offered in the tender rely on a high proportion of overlap between the adjacent search lines to cover the nadir area. Similarly, more accurate positioning of the vehicle requires less overlap at the edge of the sonar swath to ensure complete coverage between search lines. The Fugro search vehicles are positioned using a combination of instruments on the surface vessel and underwater vehicle. An inertial navigation system in the search vehicle provides primary positioning which is corrected to an accuracy of around 50 metres using a very long range ultra-short baseline (USBL) acoustic positioning system to provide a very accurate position solution even in the deep waters of the search area.
While most of the other deep tow systems offered in the tender were also equipped with USBL systems, the ultra-deep water in the search area, where the deep tow vehicle may be up to 9 km behind the search vessel, is beyond the effective range of most of these systems. The effectiveness of any USBL system is also compromised when it is mounted on an acoustically noisy vessel. The Fugro vessels, which are also used for hydrographic survey work, are designed and built to be acoustically quiet and therefore the USBL positioning systems have been found to be very reliable and accurate."
That's it for now,
LabratSR
LabratSR from Twitter here. Just stopping by to say hi and thank you guys for the great work you are doing.
I have been particularly transfixed by the AQON posted above. The selection of Fugro was always a puzzle to me, however, I am certainly no expert in such things.
I sent the AQON to a guy (thommo101) that rarely posts on Reddit but is a sonar and sub sea systems guy that even worked on a quote for a company that planned on bidding for the search contract.
He posted his comments in this thread.
https://www.reddit.com/r/MH370/comments/...use_furgo/
"Whilst I'm not an expert at sonar imaging, reading through the the tender response to the shortlisted tenderers (PDF page 55 on) it all makes sense.
The Svitzer Salvage proposal has a few negatives, use of low frequency SSS (unsure how they could meet resolution requirements when proposing use of large swaths), and the chosen vessel types which would be slow to transit and noisy.
The Phoenix tender looks pretty good, but synthetic aperture sonars are not yet as trusted due to their increased complexity and reliance on accurate inertial reference units. When they work, they work well. When they don't...
Fugro, well, they have some very nice ships dedicated to this type of work, which were available (also a plus for the tender). Using conventional proven sensors and survey techniques. I understand why they were picked. I'm pretty sure that James Fisher (who contacted us early on in the tender process for advice) ended up not bidding because they thought Fugro would be a shoe-in."
Further, I found this quote from the AQON to be on point and interesting.
"The vehicles (both deep tow and autonomous underwater vehicle or AUV) currently used in the search by Fugro Survey Pty Ltd (Fugro) use an independent sonar instrument to cover the nadir area (a multi-beam echo sounder) whereas other systems offered in the tender rely on a high proportion of overlap between the adjacent search lines to cover the nadir area. Similarly, more accurate positioning of the vehicle requires less overlap at the edge of the sonar swath to ensure complete coverage between search lines. The Fugro search vehicles are positioned using a combination of instruments on the surface vessel and underwater vehicle. An inertial navigation system in the search vehicle provides primary positioning which is corrected to an accuracy of around 50 metres using a very long range ultra-short baseline (USBL) acoustic positioning system to provide a very accurate position solution even in the deep waters of the search area.
While most of the other deep tow systems offered in the tender were also equipped with USBL systems, the ultra-deep water in the search area, where the deep tow vehicle may be up to 9 km behind the search vessel, is beyond the effective range of most of these systems. The effectiveness of any USBL system is also compromised when it is mounted on an acoustically noisy vessel. The Fugro vessels, which are also used for hydrographic survey work, are designed and built to be acoustically quiet and therefore the USBL positioning systems have been found to be very reliable and accurate."
That's it for now,
LabratSR