IFF real procedures

[Joni]

Hi guys,

 

I would like to know more about the real operation on the two IFF (interrogator and transponder) equipments that are aboard the Mirage.

 

For example, the transponder behind the stick has the code number you will be replying, but the interrogator also has a 4 digit code window. What does that do? And what are the interrogator modes?

 

If I switch the transponder behind the stick off, will I stop replying to interrogations and show as enemy?

 

Im a civilian pilot so I know how the transponder works (most of it at least), but have not much knowledge about interrogators.

 

 

Thanks!

[jojo]

This is a limit of DCS here which doesn't fully simulate IFF procedure for now.

 

The transposer behind the stick allows to set in cockpit Mode 1 & 3 ©.

Mode 3 C being the equivalent of civilian mode, and C gives the altitude data from the altimeter.

It also allows to activate Mode 4 and to choose between 2 pre-loaded code (A or B).

The pilot can't set the Mode 4 code, it's encrypted and very sensitive date.

 

The IFF interrogator allows to select which mode to interrogate and set what code is friendly (apart from mode 4 I guess).

 

The only thing you can do on DCS M-2000 is turn on the interrogator, and click the HOTAS button to get a temporary answer from friendlies contacts.

If you don't do these 2 actions before firing you may shoot "blue on blue" :music_whistling:

 

It's very few but already a step up from FC3 modules which have automatic and permanent "magical" IFF. DCS assume IFF depending on coalition.

[BlazingTrigger]

There is normally a secure code, quite long that's changed daily and so if interrogated you'll show as friendly if another aircraft has the same code loaded as it'll cross refer it to the one it has loaded and so can determine friend from foe. I believe that's how real life IFF works on combat aircraft

 

Sent from my Pixel using Tapatalk

[BlazingTrigger]

Edit: the section I was referring to is mode 4, in the UK it's called Crypto and is loaded before a flight and very few people know what the code is, the next day the code is useless so a new one is made

 

Sent from my Pixel using Tapatalk

[jojo]

That's what I said. This is why you have Mode 4 code A and B. In case you must fly past midnight or something like that...you can switch the codes.

[Joni]

So those digits on the interrogator are to tell it what is friendly? So if I put 4376 and the mode 3/3, only aircraft that put mode 3 and 4376 code on their transponder will show friendly to me?

 

What if there are other air forces nearby? Of course they will not use the same code as my squadron. They'll show foe?

 

That doesnt seem right somehow.

[SDsc0rch]

The only thing you can do on DCS M-2000 is turn on the interrogator, and click the HOTAS button to get a temporary answer from friendlies contacts.

If you don't do these 2 actions before firing you may shoot "blue on blue" :music_whistling:

 

It's very few but already a step up from FC3 modules which have automatic and permanent "magical" IFF. DCS assume IFF depending on coalition.

 

IFF should be standardized across DCS - if it is automatic in the aircraft, it should be automatic in the sim - if you've got to actively initiate an IFF query in the aircraft, DCS should model it

[jojo]

You don't have to interrogate the full 4 digits. You can only interrogate the first 2 or 3 digits.

 

But like we said, in war time what count is Mode 4.

You only choose to interrogate the Mode 4, the dials doesn't count for Mode 4 AFAIK.

[jojo]

IFF should be standardized across DCS - if it is automatic in the aircraft, it should be automatic in the sim - if you've got to actively initiate an IFF query in the aircraft, DCS should model it

 

For what I know, no fighter continuously emit interrogation.

IIFF can betray your presence. This is why you have continuous or sectorial interrogation on M-2000.

 

But that aspect of electronic warfare isn't simulates within DCS.

 

M-2000C is the first AA fighter DCS module. We'll see how it's handled with Hornet and Tomcat.

 

Last thing, IFF doesn't say who is foe, it only says who is friendly.

IRL IFF can fail. This why during Iraki Freedom in 2003 a Patriot battery set to automatic shot down a British Tornado. I think there was a case with a Hornet too.

 

Then only exception was during Vietnam war. US did crack North Vietnamese IFF, and created a system called "Combat Tree", which triggered the MiG IFF. Very convenient...

[SDsc0rch]

+1

[Joni]

You don't have to interrogate the full 4 digits. You can only interrogate the first 2 or 3 digits.

 

But like we said, in war time what count is Mode 4.

You only choose to interrogate the Mode 4, the dials doesn't count for Mode 4 AFAIK.

 

I dont understand that. How do you choose how many digits you want to interrogate and what does that have to do with my noob example before?

 

Sorry, this is one of the few systems I never studied.

[jojo]

It's related to the mode selector:

1 - 4 - 3/2 - 3/3 - 3/4 - 2

And the selector G / D (Left/ Right).

 

But anyway, this is irrelevant in DCS.

 

For DCS, turn it on, push the HOTAS button...done !

[jojo]

By the way: you're welcome !

[Fri13]

Just for asking....

 

For the mode 4 code, is it really just short string of numbers or something? As I have thought that it should be more like a 12 character long or something that is impossible to crack in the period of time when it is usable....

 

With the limitations of change to get the system simulated accurately, IFF is again one of those things where I would totally accept it to be done in basic "estimations" manner by knowing just by what it should really be able to do (to tell is the target friend) so we would be required to go checking every contact that doesn't respond as "friend" so visually know is it a foe.

 

But all that would as well require that the Combined Arms would start to support more realistic radar systems and require human players to really dive in for the systems closer to the SAM system screens etc instead basic F10 map.

 

Maybe one day we get again closer that IFF system procedure where we can simulate it in basic manner and have fun to do even alone the random checks etc.

[Joni]

It's related to the mode selector:

1 - 4 - 3/2 - 3/3 - 3/4 - 2

And the selector G / D (Left/ Right).

 

But anyway, this is irrelevant in DCS.

 

For DCS, turn it on, push the HOTAS button...done !

 

I wanted to learn about the system, not how its done in dcs.

 

Thanks?? We werent finished yet :thumbup:

[GGTharos]

For what I know, no fighter continuously emit interrogation.

 

But many have the option to. The 63 does and I figure the 73 does also. Like you said, most of EW is not simulated ... Then again if you're in radar search detection via IFF probably doesn't matter.

 

This why during Iraki Freedom in 2003 a Patriot battery set to automatic shot down a British Tornado. I think there was a case with a Hornet too.

 

I have the investigation files for these incidents somewhere. I don't believe the IFF was the point of failure but it may have contributed. All IIRC, the depositions are quite long and I don't want to go through them again.

 

Then only exception was during Vietnam war. US did crack North Vietnamese IFF, and created a system called "Combat Tree", which triggered the MiG IFF. Very convenient...

 

I don't know how to tell you this, but the real apg63 has 3 AAI symbols ... Friendly, unknown and ENEMY ;)

[VampireNZ]

But many have the option to. The 63 does and I figure the 73 does also. Like you said, most of EW is not simulated ...

 

Depends on system and operator settings. Without going into specifics, there are heaps of different user settings for all sorts of different triggers to transmit, auto-scan, manual profiles etc. I will also say the IFF system works in conjunction with the RADAR, and leave it at that.

Edited July 31, 2017 by VampireNZ

[Joni]

It's related to the mode selector:

1 - 4 - 3/2 - 3/3 - 3/4 - 2

And the selector G / D (Left/ Right).

 

But anyway, this is irrelevant in DCS.

 

For DCS, turn it on, push the HOTAS button...done !

 

Ok, so you only interrogate the first two or the last two, is that right? Im interpreting this based on the G/D switch and the lines in the windows. Am I right?

 

And the mode selector selects the mode you will be interrogating right?

[Azrayen]

No you aren't right.

G/D is for mode 1.

 

And yes, (quite amazingly) the mode selector selects the mode. (sorry, couldn't resist :D)

[Joni]

No you aren't right.

G/D is for mode 1.

 

And yes, (quite amazingly) the mode selector selects the mode. (sorry, couldn't resist :D)

 

Whats quite amazing is the level of detail of your answer :doh:

 

Sorry me neither :D

[Azrayen]

Indeed. :) Damn phone and its little keyboard.

Your assumption was correct but, as I said, only for mode 1. And if you search how this one works, you'll soon get it.

Following the lines seems a good idea. There are more of them, plus the mode selector stops.

[jojo]

For anyone interested in how a real IFF set works go read here from P101 (early F-15)

http://www.avialogs.com/en/aircraft/usa/mcdonnelldouglas/f-15eagle/to-1f-15c-34-1-1-nonnuclear-weapon-delivery-manual-air-to-air-f-15c-and-f-15d-aircraft.html

[jojo]

I don't know how to tell you this, but the real apg63 has 3 AAI symbols ... Friendly, unknown and ENEMY ;)

 

Still curious to hear how the F-15 AAI system would tell the difference between a friend with IFF off and a foe with IFF off :music_whistling: (apart from NCTR)

[Joni]

I think i got it, it confused me when you said we could interrogate two or three digits, thats not accurate based on reading the article.

 

Thanks for the help

 

EDIT: maybe I jumped too fast, if I input only two or three digits will it only check for those? There's also the possibility Im right and if you put two or three then the interrogator will check for the whole number with the zeros and return not friendly.

Edited August 1, 2017 by JohnnyQ

[jojo]

Yet the IFF interrogator isn't exactly the same in F-15C and Mirage 2000.