Datalinks

[Todjaeger]

I'm seeking information on the way datalinks work. More specifically Link 11 and Link 16.

I'm aware of the general operations, as follows.

For example Aircraft A (E-2C Hawkeye) detects an aircraft contact, and relays it to Aircraft B (F/A18-E) which is then able to engage with a BVR missile, without turning it's own radar on. Similarly, a vessel detects another ship, and relays position to a second ship, which is then able to launch SSM against the detected ship, despite not being able to locate with it's own onboard radar.

What I'm wondering specifically is.

For situation #1 above, the detecting sensor is aboard the E-2C, but which aircraft is carrying the system which achieves the target lock? The Hawkeye or the Super Hornet? What information does the Link (11,16, etc) relay to inform other aircraft/vessels what it detects? Does it relay information comparable to a GIS, or is it completely different.

Any info that can be posted, or links/sources where such info can be found would be greatly appreciated.

-Cheers

 

[butch4343]

Hi

Ok I cant say for sure on this but I suspect your E2C/F18E Scenario would involve AIM-120 Amraams, If so as far as I can recall lock on does not need to be achieved until after launch. The AIM-120 after launch recives an mid-course update to take account of target manouvering, usally this would be from the launch platform , but as long as the data reaches the weapon it cares not where it came from. In fact IIRC the AIM-120 can be fired without the mid-course update, although this can lower the AIM-120 Pk factor.

In your second scenario, are we talking AShMs with terminal active radar guidance (Harpoon,Exocet )? If we are, the ship that is acting as the radar emitter, merely tells the shooter ship where the target is and the mission planners in the CIC where the target is, they then programme the weapons flight path acordingly and enter the minimum range the weapons active seeker emits at.

As I said I am not 100% sure on this , so I stand to await correction, hope this helps

 

[Todjaeger]

Hi

Ok I cant say for sure on this but I suspect your E2C/F18E Scenario would involve AIM-120 Amraams, If so as far as I can recall lock on does not need to be achieved until after launch. The AIM-120 after launch recives an mid-course update to take account of target manouvering, usally this would be from the launch platform , but as long as the data reaches the weapon it cares not where it came from. In fact IIRC the AIM-120 can be fired without the mid-course update, although this can lower the AIM-120 Pk factor.

In your second scenario, are we talking AShMs with terminal active radar guidance (Harpoon,Exocet )? If we are, the ship that is acting as the radar emitter, merely tells the shooter ship where the target is and the mission planners in the CIC where the target is, they then programme the weapons flight path acordingly and enter the minimum range the weapons active seeker emits at.

As I said I am not 100% sure on this , so I stand to await correction, hope this helps

As part of the Link system, the radar emitter vessel/aircraft does, AFAIK, tell the shooter where the target is. What I'm interested in finding out, is how it goes about this. Does it transmit GPS coordinates, or is there other information that is transmitted. Granted, this might be classified info, in which case I'm out of luck.

-Cheers

 

[tphuang]

actually, one of the questions I've always had was how do ships and aircraft communicate with each. From a technical point of view, it doesn't seem possible for one side to be transmitting in link 16 format and the other side receiving using link 11 format. So, the most obvious solution is that most ships also have something that can receive send and receive link 16 messages and can convert bw link 16 and link 11 format, right?

 

[Todjaeger]

actually, one of the questions I've always had was how do ships and aircraft communicate with each. From a technical point of view, it doesn't seem possible for one side to be transmitting in link 16 format and the other side receiving using link 11 format. So, the most obvious solution is that most ships also have something that can receive send and receive link 16 messages and can convert bw link 16 and link 11 format, right?

Are you sure the aircraft and vessels you're referring to have different Link systems? As an example, the current RAAF and RAN aircraft and vessels are making use of Link 11 (except possibly for the Seahawk & FFG-7 frigates). However, there are upgrade plans to switch over to Link 16.

I suppose that it's possible for a Link 16 device to have as an additional feature the ability to communicate with Link 11 device. That might also be how the communications you're referring to are occuring. I don't imagine that a Link 11 could convert to a Link 16 level, but it makes sense that Link 16 could convert back down to Link 11. Still, this is all guesswork on my part.

-Cheers

 

[AegisFC]

The USN's CDLMS (Common Data Link Management System) can handle both Link 11 and 16, and can take the data from Link 16 ships and convert it and retransmit it on Link 11 and vice versa.

 

[barra]

Todjeager,

Link 16 and Link 11 are two totally different systems. Link 16 is a UHF line of sight system and Link 11 is a HF system used mainly in the maritime enviroment. Link 16 is not replacing Link 11 as such, platforms such as AWACS will be able to link both nets together so track files may be displayed on both sytems. If link 11 was removed from surface ships LOS for Link 16 would be restricted to about 20 miles without aircraft to relay messages. So you see they play different roles.

Hooroo

 

[kato]

Isn't Link 22 supposed to replace both Link 11 and Link 16 (as onboard systems)?

 

[radiosilence]

Isn't Link 22 supposed to replace both Link 11 and Link 16 (as onboard systems)?

Link 22 is an improved version of Link 11 which will replace Link 11 when its become operational. It was not meant to replace Link 16 but to compliment it. Both Link 11 and Link 22 operate on HF and UHF frequency bands, whereas Link 16 only uses UHF.

 

[kato]

It was not meant to replace Link 16 but to compliment it.

Hmm, thought i read somewhere that Link 22 is able to send Link 16 -compatible data packets.