[Josh]

Random thought occured to me...I once found a study on dropping sonobuoys from high altitude and having them not retard until low altitude, for high altitude placement. The study found the absolute high end of being able to reliably place buoys was under ten thousand feet. But it occured to me, since the buoy is radiating its signal to the parrent platform (P-3), can't the P-3 orbit a bit and triagulate the exact site of the buoy? At which point, even if your pattern was a bit off, at least you would know where any targets were relative to the location of the buoy. Also, since the main factor in moving the buoys off intended location from high altitude drop would be cross winds, I would have thought the entire patter would tend to slide in one direction, not randomly dispersed. Also, tracking a single buoy could then allow for wind corrections to be added to future drops. Would this be at all practical for placing buoys from high altitude? I was basically wondering in the context of the P-8 and logshot delivered torpedeos being used from altitude...would an ASW plane need to come down from altitude for anything but a MAD run?

[Justin]

Wouldn't you just be able to put some kind of a cheap gps receiver on the buoy to get fairly exact placement information that could then be sent to the parent craft? I guess if you really really needed to have super high altitude placement of sonobuoys they could always develop some kinda JDAM kit for them. I can see operating at a high altitude being an advantage for fuel saving measures and putting the aircraft out of SAM range of snorkeling boats ect but wouldn't that also increase the engagement time on a target quite a bit having to drop down a significant distance in altitude to make your MAD run and then deploy a torpedo against the target.

[Brasidas]

Correct on the miniature GPS receivers.

Actually, if you think about the latest advancements in miniaturization for receivers, transmitters, and signal analysis that could be fit on a buoy, along with advancements in sub-munition dispersal from a JDAM like delivery vehicle, there shouldn't be any reason a P-8 couldn't drop a pattern almost anywhere it wanted from a higher altitude and get an exact Geodetic fix from the buoys almost as soon as they hit the water. This doesn't consider any use of higher density power sources or even use of solar power to extend the endurance of buoys.

[Josh]

Justin, on Thu 26 Mar 2009 2137, said:

Wouldn't you just be able to put some kind of a cheap gps receiver on the buoy to get fairly exact placement information that could then be sent to the parent craft? I guess if you really really needed to have super high altitude placement of sonobuoys they could always develop some kinda JDAM kit for them.

I was thinking of using existing stocks of type A buoys. Also, there is a JDAM type kit privately developed called SPAD, Sonobuoy Precission Air Deployment, however it takes up half the tube and only can be attached to half sized (A2?, G?) sized buoys. Price I expect also is an issue with such a otherwise disposable asset; I suspect that the kit costs as much as the buoy.

I can see operating at a high altitude being an advantage for fuel saving measures and putting the aircraft out of SAM range of snorkeling boats ect but wouldn't that also increase the engagement time on a target quite a bit having to drop down a significant distance in altitude to make your MAD run and then deploy a torpedo against the target.

I don't think MAD is required for engagement. MH-60R actually deleted the MAD boom for ASW. Some subs are titanium or have been wiped and won't read on MAD anyway. Given a directional active pinger on the target, like DIFAR (IIRC), I think target data is perfectly doable using onlyl buoys. There are also some more modern bistatic buoys to be used with command detonated explosive buoys for a loud active ping; I assume two of them receiving different echos from different bearings could give a very exact location with triangulation as long as the buoys location was very accurate. So I think the a/c can just release a glide kit delivered torp from altitude and never come down from that height if the buoys can be accurately laid; hence my question.

Other advantages besides fuel consumption: less ware on the airframe and larger detection radius of the other sensors (except MAD--surface search radar, electro optical, thermal, ESM, etc)

Edit for spelling


2nd Edit: So Brasidas, do current buoys employ GPS? Are they usually deployed from altitude now?

This post has been edited by jua: 27 March 2009 - 1237 PM

[Brasidas]

jua, on Fri 27 Mar 2009 1734, said:

Edit for spelling
2nd Edit: So Brasidas, do current buoys employ GPS? Are they usually deployed from altitude now?

No, present technology and methodology is to use low altitude deployments. Not sure if there are presently GPS position transmitters on USN sonobuoys, but there really should be.

[Cromwell]

As a matter of interest, how much does your basic western sonarbuoy cost?

[Burncycle360]

With GPS and glide kits, would it be technically plausible to just drop a bunch of sonobouys all at once and have them land at predesignated spots on a grid? Would it represent a significant leap in ASW effectiveness?

[shep854]

With a sonobuoy pattern, what is important is the position of each buoy in relation to the others to get the desired sonar/listening coverage. The farther a group of objects fall, the greater the dispersion, unless active measures are employed. If you release the buoys from too high, they disperse too much to give adequate coverage of the datum.

[Josh]

Burncycle360, on Sun 5 Apr 2009 2244, said:

With GPS and glide kits, would it be technically plausible to just drop a bunch of sonobouys all at once and have them land at predesignated spots on a grid? Would it represent a significant leap in ASW effectiveness?

On the former, yes that would be possible. The SPAD system I mentioned does that. How much this increased effectiveness as opposed to laying them individually I don't know. It would definately increase expense.

[Josh]

shep854, on Mon 6 Apr 2009 0304, said:

With a sonobuoy pattern, what is important is the position of each buoy in relation to the others to get the desired sonar/listening coverage. The farther a group of objects fall, the greater the dispersion, unless active measures are employed. If you release the buoys from too high, they disperse too much to give adequate coverage of the datum.

My understanding is that the dispersion was largely similar across all the drops. So the entire pattern might be a bit looser, but would tend to drift all in the same direction. I suspect patterns aren't severely disrupted by high altitude drops as long as buoy positions are able to be established; the study I read done in the 80's seemed to indicate that patterns were only off by hundreds of meters. How close are they usually employed? I was under the impression buoys could be separated by miles...

[Josh]

Apparently the navy is thinking along these lines; they have a requirement for a high altitude deployment system. However the system must take up no more space than the standard deceleration package on an A class 36" buoy and must *not* use GPS:

http://www.navysbir...._1/N081-023.htm



Apparentlly GPS on a buoy has several issues including cost, power, reception of signal when at such a low altitude/submerged, and alignment when stored for years deactivated:

http://www.navsys.co...ers/9609007.pdf

[Brasidas]

jua, on Tue 12 May 2009 0224, said:

Apparently the navy is thinking along these lines; they have a requirement for a high altitude deployment system. However the system must take up no more space than the standard deceleration package on an A class 36" buoy and must *not* use GPS:

http://www.navysbir...._1/N081-023.htm
Apparentlly GPS on a buoy has several issues including cost, power, reception of signal when at such a low altitude/submerged, and alignment when stored for years deactivated:

There are only three issues for using military GPS that are actual issues. That BS about power consumption is nothing but BS.

1)The PPS encryption keys would have to be loaded for each receiver.

2)A PPS receiver would take fifteen minutes just to load the overhead almanac if they didn't have an update capability before deployment.

3)Using an active antenna does consume more power, but they are not "needed" to use gps even at sea level. Examples abound.

Nice to see the USN bureacracy is gonna lose the next war for us by thinking within strictly defined boxes.

P.S. That paper is a bit old you know. It doesn't account for any hardware/software advancements in the last 15 years.

This post has been edited by Brasidas: 12 May 2009 - 1034 AM

[Josh]

A little further research found that the maker of most USN buoys did have some GPS options on their more advanced models. But apparently cost is still a factor even if reception isn't. The first requirement I posted was 2007; I can't imagine GPS tech has change drastically since. The buoys I saw with the GPS option was a 'barra' type array; the thing sprouts sensors like an octopus and I think its not for routine dispersal but more for triangulation in three dimensions (attacking a previously detected target). That said, look at a few of the articles I've read re-investigating the issue, buoys have come a long way. They tend to be multistatic arrays feeding pre-analyzed data back to the parrent platform. I'm not hip to ASW enough to fully gauge how effective that makes them, but one thing I did note is that modern types seem to be universally compatible with some kind of active illumination, be it a electric pinger or just command detonated explosives for broad band noise.

[Brasidas]

jua, on Thu 14 May 2009 0422, said:

A little further research found that the maker of most USN buoys did have some GPS options on their more advanced models. But apparently cost is still a factor even if reception isn't. The first requirement I posted was 2007; I can't imagine GPS tech has change drastically since. The buoys I saw with the GPS option was a 'barra' type array; the thing sprouts sensors like an octopus and I think its not for routine dispersal but more for triangulation in three dimensions (attacking a previously detected target). That said, look at a few of the articles I've read re-investigating the issue, buoys have come a long way. They tend to be multistatic arrays feeding pre-analyzed data back to the parrent platform. I'm not hip to ASW enough to fully gauge how effective that makes them, but one thing I did note is that modern types seem to be universally compatible with some kind of active illumination, be it a electric pinger or just command detonated explosives for broad band noise.

When I referred to "the paper" I meant the paper with studies (dated 1993) and then rerun in 1995 in full trials. There has been an immense amount of advancement in GPS reception and power consumption technology since the initial and full scale tests you referenced in that paper. SBIRs don't mean anything official anyway. Just that the PMAs in question are getting their small business solicitation out of the way before they put it out there for the big boys who will actually fill the requirements.

[Kenneth P. Katz]

You have described something that is referred to as an sonobuoy reference system. Combined with an INS, a digital computer and a graphical display, this was the basis of the enormous advance in airborne ASW provided by the P-3C and S-3A. The previous method had to been to get a fix on the sonobuoy by flying over it and marking its position with a grease pencil. Needless to say, that wasn't going to work against a fast nuclear submarine.

AN/ARS-2 S-3A Viking, (?) P-3C
AN/ARS-3 P-3C Update II
AN/ARS-4 S-3B Viking
AN/ARS-5 P-3C Update III

jua, on Thu 26 Mar 2009 2107, said:

But it occured to me, since the buoy is radiating its signal to the parrent platform (P-3), can't the P-3 orbit a bit and triagulate the exact site of the buoy?