[Milsurplus] More info - DIFAR ASW system on P3

[Al Klase]

Don't miss the tour!  It's excellent. - Thanks, Al

On 7/6/2020 10:02 AM, Brian Harrison wrote:
> All,
>
> Here’s a response from Bill Baker of The Hickory Aviation Museum
> (If anyone wants Bill’s email pse email me directly)
>
> Tnx,
> brian
> kn4r
> *
> *
> *...*
>
> That system was the AQA-7 that "burned" the recorded data on paper.  
> In it's original form it was call the "Jezebel" and we'd often call 
> the acoustic operators "Jez" even after it was long gone from the 
> aircraft.   It would scroll like a fax machine and at the end of the 
> mission, the paper would be turned in to the debriefing gang for 
> reconstruction.  One positive thing was the paper was an immediate 
> visible replay of the information gained by the sonobuoys and the 
> operators would also write and do computations on the paper itself. 
> Plus an operator could cut off the paper and remove from the machine 
> and review back in time while on the mission to maybe see if contact 
> was missed.   The negative was the nasty smell this machine 
> produced!!!!!!!   Initially the buoys were "Lofar", or basically the 
> buoy would detect a sound and give the operator a circle around the 
> buoy and it would take multiple buoys to localize to a small area to 
> search.  "Difar" buioys, which provide sound recordings, but more 
> importantly, direction from the buoy were the next important tool to 
> be developed and replaced Lofar.  Two or three buoys with lines 
> pointing to a noise source and there it is where those lines 
> intersect.  The USN went away from the AQA-7 when the P-3C Update III 
> came on line in the mid 1980s.  The acoustic processing system was now 
> all computerized, Lofar buoys were a thing of the past.  The new 
> system was called the UYS-1, and the big and probably final upgrade to 
> that system was introduction "CHEX" or channel expansion, allowing the 
> aircrews to have 99 channel capabilities for buoy channel numbers of 
> buoys instead of only 32.   Now, all the data is recorded on tapes 
> that had to be replayed on ground based computer systems to review the 
> mission and compare with operator notes.  (Operators could not do this 
> in-flight).  That system is what is featured in the Hickory Aviation 
> Museum's P-3C, with plasma panels to enter data and manipulate the 
> buoys.  When flying, the operator on the right was the lead, he'd 
> usually do the Difar work, which was passive only, just listening for 
> noise.  The other operator was usually in training and would help and 
> also do the Dicass, or active buoys should they be authorized. Dicass 
> would provide a range and bearing from buoy to target with burst of 
> energy, just like sonar..   I flew on aircraft with both systems, and 
> a lot comes down to the quality of the operator and numerous other 
> factors such as oceanographic conditions, and of course, the target 
> itself.  Hope that answers the question, if not, let me know., I had 
> 3k+ hours flying P-3C’s.
>
> Hickory Aviation Museum - 
> http://www.hickoryaviationmuseum.org/welcome.html
>
> P3-C interactive tour - 
> https://my.matterport.com/show/?m=4UgzaEpRdwr&utm_source=4
>
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-- 
Al Klase – N3FRQ
Jersey City, NJ
http://www.skywaves.ar88.net/

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