Using sonar for navigation?

Marcantilan · 12-06-08, 06:41 PM

Hello well versed fellows.

Here´s my question. If you are in a submarine, could you use your active sonar for navigation (avoiding submerged rocks, etc) Or could you "fix" your position with a sonar echo?

In that regard, a military active sonar has the same capabilitie (well, not the same...) as a Decca series radar, for example?

Thanks!

SteamWake · 12-06-08, 09:37 PM

Perhaps contemporary submarines with their 3d imaging sonar but with WW2 subs youd be lucky to not run into the bottom.

PeriscopeDepth · 12-07-08, 12:19 AM

Modern subs just need a GPS fix every now and then to update their inertial nav systems. I can't see where active sonar would fit into this unless they are doing something requiring a LOT of precision. And something where you don't mind giving away your position.

PD

Frame57 · 12-07-08, 07:22 AM

The fathometer is what is used to hopefully make sure one does not run aground. HF sonar is used for navigational purposes. Go ICEX 79!

Marcantilan · 12-07-08, 01:24 PM

In fact, I´m thinking in the HMS Onyx and her collision (back in 1982 - look at the "HMS Onyx pics wanted post") with a submerged rock while she was on a covert ops mission.

Could the collision be avoided with a active sonar switched on?

Frame57 · 12-08-08, 12:06 PM

Hmmmm? Well, you may want to post this in the DW section here. There are a couple of former Sonar techs who could answer this for certain. I was an A-ganger so my knowledge is limited with regards to sonar.

However, I do know that HF works best for navigational purposes like detecting Ice bergs, Mines and operating under the polar caps. A rock being submerged? Well I would think the rock would have to be part of a land mass because rocks generally do not float or have neutral bouyancy, so again I think either they did not have a fathometer or it was not turned on in order to avoid this situation. The signal bounced back from active sonar will be dependant upon signal strength, target distance and density and thermal condition etc.. so I cannot say yea or nay but someone here will I am sure.

seafarer · 12-09-08, 10:02 AM

Quote:

Originally Posted by Marcantilan

In fact, I´m thinking in the HMS Onyx and her collision (back in 1982 - look at the "HMS Onyx pics wanted post") with a submerged rock while she was on a covert ops mission.

Could the collision be avoided with a active sonar switched on?

Would kind of take away from the "covert" aspect to use active sonar.

geetrue · 12-09-08, 02:54 PM

Quote:

Originally Posted by Frame57

The fathometer is what is used to hopefully make sure one does not run aground. HF sonar is used for navigational purposes. Go ICEX 79!

How close you are, but there is more than one fathometer on board. The nav techs also had a HF fathometer and if the SINS system didn't agree with the reading of the fathometer the alarms would go off.

Seems the whole Med had been mapped underwater from the numerous travels of other submarines and perhaps a lot more than just the Med by now.

Remember this was 37 years ago ... I haven't been on a modern boat and I doubt if they would explain it to me anyway.

Yes, sonar can be used to navigate, but we sure did hate the surface craft navies using it on us.

Frame57 · 12-09-08, 08:11 PM

I hear ya there, its been 20 years now since I have been there too, thanks for the info on the fathometer.

12-06-08, 06:41 PM	#1
Marcantilan Weps Join Date: Sep 2004 Location: Buenos Aires, Argentina Posts: 374 Downloads: 3 Uploads: 0	Using sonar for navigation? Hello well versed fellows. Here´s my question. If you are in a submarine, could you use your active sonar for navigation (avoiding submerged rocks, etc) Or could you "fix" your position with a sonar echo? In that regard, a military active sonar has the same capabilitie (well, not the same...) as a Decca series radar, for example? Thanks! __________________ Ultima Ratio Regis

12-07-08, 01:24 PM	#5
Marcantilan Weps Join Date: Sep 2004 Location: Buenos Aires, Argentina Posts: 374 Downloads: 3 Uploads: 0	In fact, I´m thinking in the HMS Onyx and her collision (back in 1982 - look at the "HMS Onyx pics wanted post") with a submerged rock while she was on a covert ops mission. Could the collision be avoided with a active sonar switched on? __________________ Ultima Ratio Regis

12-06-08, 09:37 PM	#2
SteamWake Rear Admiral Join Date: Mar 2005 Posts: 13,224 Downloads: 5 Uploads: 0	Perhaps contemporary submarines with their 3d imaging sonar but with WW2 subs youd be lucky to not run into the bottom.

12-07-08, 12:19 AM	#3
PeriscopeDepth Sea Lord Join Date: Jul 2002 Location: Pacific NW Posts: 1,894 Downloads: 6 Uploads: 0	Modern subs just need a GPS fix every now and then to update their inertial nav systems. I can't see where active sonar would fit into this unless they are doing something requiring a LOT of precision. And something where you don't mind giving away your position. PD

12-07-08, 07:22 AM	#4
Frame57 Sea Lord Join Date: May 2008 Location: 1300 feet on the crapper Posts: 1,860 Downloads: 2 Uploads: 0	The fathometer is what is used to hopefully make sure one does not run aground. HF sonar is used for navigational purposes. Go ICEX 79!

12-08-08, 12:06 PM	#6
Frame57 Sea Lord Join Date: May 2008 Location: 1300 feet on the crapper Posts: 1,860 Downloads: 2 Uploads: 0	Hmmmm? Well, you may want to post this in the DW section here. There are a couple of former Sonar techs who could answer this for certain. I was an A-ganger so my knowledge is limited with regards to sonar. However, I do know that HF works best for navigational purposes like detecting Ice bergs, Mines and operating under the polar caps. A rock being submerged? Well I would think the rock would have to be part of a land mass because rocks generally do not float or have neutral bouyancy, so again I think either they did not have a fathometer or it was not turned on in order to avoid this situation. The signal bounced back from active sonar will be dependant upon signal strength, target distance and density and thermal condition etc.. so I cannot say yea or nay but someone here will I am sure.

12-09-08, 08:11 PM	#9
Frame57 Sea Lord Join Date: May 2008 Location: 1300 feet on the crapper Posts: 1,860 Downloads: 2 Uploads: 0	I hear ya there, its been 20 years now since I have been there too, thanks for the info on the fathometer.