F-15 TWS/Soft Locking Unrealistic?

[The AMRAAMer]

In Falcon BMS and DCS: Mirage 2000, not locking up a target will put you in RWS mode. Locking a target once, aka soft-locking will put you in TWS mode. And locking it twice will put you in STT mode.

 

In the F-15 however, a single lock while in RWS mode will put you in STT mode. If you want TWS, you'll have to switch to it with the keybind.

 

Why doesn't the F-15 RWS mode put you in TWS after you lock something up the first time, instead of going straight to hard locking in STT mode?

[PeaceSells]

DCS F-15C is a Flaming Cliffs 3 aircraft and because of that, except for the flight model, it's meant to be a "moderate realism" plane. Radar and systems are not accurate to the real life ones, you'll see many other things that don't correlate.

[Buckeye]

DCS F-15C is a Flaming Cliffs 3 aircraft and because of that, except for the flight model, it's meant to be a "moderate realism" plane. Radar and systems are not accurate to the real life ones, you'll see many other things that don't correlate.

 

Yup, it will be great when the Hornet and Tomcat are out so we can finally have something that behaves realistically without all the unrealistic oddities in the systems (or systems missing altogether).

 

If you want that at the present, you'll need to check "the other" modern fighter sim.

[KlarSnow]

Because thats not how TWS and RWS work in the F-15.

Just because it is an american jet and follows similiar conventions to what is in the F-16/18 does not at all mean the HOTAS or mechanization is similiar. I would expect the hornet to be a completely different beast as far as radar mech as well.

 

The F-15 radar (mech scanned version) does not "Soft lock" things. Commanding a lock puts you into STT just like in DCS. You have to actively switch to TWS, again just like in DCS.

 

There is a lot more functionality there that we don't have in the sim but the basic mechanization is spot on for the F-15.

 

If you want why its like that. Two reasons I can think of off the top of my head.

First: McDonnell Douglas product v Lockheed product. Think iPhone V Android, you can get a lot of the same stuff done and certain conventions are the same, but how you get there is very different.

 

Second: F-15 radar and HOTAS was designed in the days when men were men and your only BVR missile was the Sparrow. Since you are only going to be shooting one target at a time you want to immediately go from search to a shootable lock, no wasting around in other modes since they are not as conducive to seeing and shooting immediately.

Edited November 7, 2017 by KlarSnow

[LJQCN101]

F18 also go STT with single designate from RWS (without LTWS selected):

 

Trackfiles can be designated by slewing the cursor over the undesignated HAFU symbol and depressing the TDC. This mechanization only applies to visible HAFU symbols (e.g. TWS, RAID, A/EL format, or RWS with LTWS selected). Attempting to designate a raw hit from VS or RWS (without LTWS selected) will instead immediately acquire it into STT.

[Svend_Dellepude]

If you want why its like that. Two reasons I can think of off the top of my head.

First: McDonnell Douglas product v Lockheed product. Think iPhone V Android, you can get a lot of the same stuff done and certain conventions are the same, but how you get there is very different.

 

Second: F-15 radar and HOTAS was designed in the days when men were men and your only BVR missile was the Sparrow. Since you are only going to be shooting one target at a time you want to immediately go from search to a shootable lock, no wasting around in other modes since they are not as conducive to seeing and shooting immediately.

 

F-15 radar (an/apg-63) was designed by Hughes and F-16 radar (an/apg-68) was designed by westinghouse. They both recieved upgrades since men were men.

 

Besides, It does make sense to have a tactical overview and not alert your intended target until you get within parameters. TWS gives you just that no matter what missile you have to use.

[probad]

this is what happens when you use f*lconbms as your point of reference

[Fri13]

Second: F-15 radar and HOTAS was designed in the days when men were men and your only BVR missile was the Sparrow. Since you are only going to be shooting one target at a time you want to immediately go from search to a shootable lock, no wasting around in other modes since they are not as conducive to seeing and shooting immediately.

 

Since you are anyways going to shoot with STT mode even AIM-120, you don't care if enemy knows it, as they are already starting to maneuver when closing to get an advantage and opening.

Why STT? So you can update the target location and not lose a lock when target maneuvers between TWS refresh.

 

And SARH seeker doesn't mean you can't shoot in TWS mode for multiple targets simultaneously, nor that you need to lock on target with STT on launch.

 

Example Mig-23 firing a R-24R at enemy was done by first finding a target via radar, then launching a missile. Then you could keep radar in search mode or even turn it Off before the counter ended and only at that point turn radar On and lock on target just a few seconds before impact and that was the few second time when the target had a change to do the correct maneuvers.

 

The procedure to swap between TWS, SWT and STT (and some other modes) just requires to be aware when to do the lock, as being totally silent does as well mean something.

 

I too find the Mirage style to go from TWS to STT a little odd, as it is easy to double press a lock button when not meant to, while chasing the target with the cursor or trying to lock on other target just next to already locked.

 

But that is that I find the Mirage radar scope cursor more difficult to use, just like with the F-15C too and requires little adapting each time entering those cockpits.

[GGTharos]

And SARH seeker doesn't mean you can't shoot in TWS mode for multiple targets simultaneously, nor that you need to lock on target with STT on launch.

 

It pretty much does mean that for fighters, the only known exception here is the MiG-31 which thanks to PESA radar can guide multiple SARH missiles simultaneously.

 

Then you could keep radar in search mode or even turn it Off before the counter ended and only at that point turn radar On and lock on target just a few seconds before impact and that was the few second time when the target had a change to do the correct maneuvers.

 

That's a great way to hit nothing, and you're making a huge assumption about a lot of things that you shouldn't be. For example, any missile might self destruct in the absence of a target for x amount of time. Likewise the target, already warned of a launch might jink and then the missile won't find it when you lock onto it again. A subsequent lock-on might be prevented for any number of reasons. Your best bet with a missile in the air is to keep a high-Pk track.

[mytai01]

F18 also go STT with single designate from RWS (without LTWS selected):

 

Same maker as F-15.

[KlarSnow]

Yup Hughes made the radar but the overall point is the people designing the user interface and how it all works and is displayed to the pilot/aircrew for the F-15C/E were a totally different set of people with different design philosophies and needs and requirements than the people doing it for the F-16. Also remember that even though there is reprogrammable/replaceable hardware (LRU's) and OFP's, there are also still quite a lot of hardware limitations to how this stuff works, which can limit the modes and capabilities you have.

 

There is no such thing as a standard, or best set of practices for this stuff. We are honestly pretty lucky that a bunch of conventions translate fairly well from one to the other.

[KlarSnow]

So for SARH missiles how are they terminally guided to their targets IE how do they go from their mid course flight to impacting/getting close enough to fuse on a small maneuvering aircraft.

 

They do this with the CW illuminator that just provides a spotlight of energy on the target so the SARH missile can always see the brightest reflection with a continuous update rate as it is making its final and usually most aggressive maneuvers.

 

So even if you could TWS shoot with SARH missiles and they datalinked their way out to targets until terminal, you would still need the CW illuminator for the endgame for each missile, which (unless you are a MiG-31 with its fancy pants Flashdance radar) you only get one of.

 

The idea that lead to the first active missiles (phoenix) was to move the CW illuminator off the aircraft and into the missile. Thus removing that need for terminal guidance from the launching aircraft, while increasing the standoff range. It eventually became simpler/more capable to just give the missile its own radar and guidance logic, which leads us to present day AMRAAM and similiar Active radar missiles.

 

Remember missile datalinks aren't magical and give the missile the full data of the lock, at an instantaneous refresh rate.It is limited by the antenna, the technology, and whatever method the transmitting aircraft has to send it. So there is latency and an update/refresh rate. Which is far slower than the speed of light(RF) updates the CW illuminator will give.

Edited November 8, 2017 by KlarSnow

[GGTharos]

Err, didn't you guys get rid of the CW illumination quite a while ago? Not sure a strike ever had one ... pretty much agree with everything except the 7M doesn't even work with CW any more (or perhaps it's just no mentioned), but using a mono-pulse seeker it works quite comfortably with PD now ... so did the F, it seems.

 

On the other hand, a mechanical radar switching SARH guidance between two different targets is just ... not very feasible which is the simple/easy explanation :)

[KlarSnow]

CW or PD doesnt change the fact a SARH missile needs constant RF energy on the target for terminal guidance.

 

We still have the CW horn in the radar on the E model with APG-70's. Have never trained or done anything for the sparrow since its old as dirt and the USAF retired it well before I went through.

[GGTharos]

Yeah we're on the same page.

[Schmidtfire]

Very interesting thread. Couple of questions:

 

If I want to fly the Eagle 1980s style with Sparrows, how was TWS used in those days?

 

Is the "launch warning" on SPO-15 rwr and the TEWS unrealistic? By that I mean, would not

the rwr have the same hardlock tone for STT lock AND launch? Or maybe a different sound during terminal phase (like the amraam)?

[Flow]

STT tracks only one target only (no antenna scanning) but does not flood the target with RF waves.

When the RWR detects RF flooding, it associates this with a launch.

 

An SARH missile needs that RF flooding to track the target.

 

The AMRAAM floods the target in its final approach when it goes autonomous.

 

Someone correct me if I am wrong :)

[GGTharos]

Very interesting thread. Couple of questions:

 

If I want to fly the Eagle 1980s style with Sparrows, how was TWS used in those days?

 

Depends on which part of the 80's. TWS was implemented in '87 IIRC. However, the radar is missing features that would have allowed presentation of extra data in RWS without locking - again, IIRC.

 

Is the "launch warning" on SPO-15 rwr and the TEWS unrealistic? By that I mean, would not

the rwr have the same hardlock tone for STT lock AND launch? Or maybe a different sound during terminal phase (like the amraam)?

 

Launches are detectable based on certain signal changes. We don't know if such a signal is available for each weapon and mode that can be used. It's a game, so launch warnings are provided.

[*Rage*]

I wonder what the game would look like without launch warnings..

[Dudikoff]

That's a great way to hit nothing, and you're making a huge assumption about a lot of things that you shouldn't be. For example, any missile might self destruct in the absence of a target for x amount of time. Likewise the target, already warned of a launch might jink and then the missile won't find it when you lock onto it again. A subsequent lock-on might be prevented for any number of reasons. Your best bet with a missile in the air is to keep a high-Pk track.

 

I remember reading that on the Soviet/Russian systems in question (with monopulse radars), dropping the lock would drop the guidance frequency so, if true, reestablishing the lock (in which case the next guidance frequency from the programmed channel would get selected) wouldn't get the missile back on track.

 

Launches are detectable based on certain signal changes. We don't know if such a signal is available for each weapon and mode that can be used. It's a game, so launch warnings are provided.

 

Or, for that matter, I guess we also don't know if the RWR's in the game (belonging to a certain time frame) were programmed to recognize them or could even detect them.

Edited November 9, 2017 by Dudikoff

[Buckeye]

I wonder what the game would look like without launch warnings..

 

A lot like when an ET comes flying through my windscreen and scares the shit out of me :music_whistling:

[GGTharos]

You can easily simulate that by having a group fly with that particular sound deleted at least, though they'll probably be flying face-in-rwr :D

 

I wonder what the game would look like without launch warnings..

[GGTharos]

I remember reading that on the Soviet/Russian systems in question (with monopulse radars), dropping the lock would drop the guidance frequency so, if true, reestablishing the lock (in which case the next guidance frequency from the programmed channel would get selected) wouldn't get the missile back on track.

 

Most of the FCS' do that. They may continue transmitting on that channel until missile time-out to prevent that channel from being used by the next missile (depends on FCS and software obviously - F-15 radar does this). Re-establishing proper information on that channel would require the radar to know that the same target has been re-locked ... this is why the time-out exists.

 

Or, for that matter, I guess we also don't know if the RWR's in the game (belonging to a certain time frame) were programmed to recognize them or could even detect them.

 

We do know for the most part, or at least we can assume they're up to a certain level of programming (ie. in RL Serbian MiG-29 RWRs had not been programmed to warn against AMRAAMs, according to a bunch of testimonies which may or may not be accurate) but there's no reason to impose this in-game.

The capability has been there at least since Vietnam, which is obvious when we watch some youtube videos which meant to train pilots on how to operate their RWR :)

In addition to this, there are air force doctrines which may turn off such warnings. Why they'd do that is beyond me (I mention the possibility because I heard that from a good authority), but it's all software.

[Schmidtfire]

Great thread! Couple of more questions:

 

IRL can the Eagle slave the AiM9 seeker ro the radar-lock for off boresight engagements?

 

In DCS the IFF just sort of works automaticly. Guess that might be classified on the real bird, but is it known for having that capability IRL?

 

In RWS/TWS mode the contacts on radar are always the same size, disregard of targeting a chopper or a An-30. Is it suppose to work like that? On the DCS Flanker, contacts have different sizes.

 

Best PRF setting to keep STT lock from failing?

[GGTharos]

Great thread! Couple of more questions:

 

IRL can the Eagle slave the AiM9 seeker ro the radar-lock for off boresight engagements?

 

Yes.

 

In DCS the IFF just sort of works automaticly. Guess that might be classified on the real bird, but is it known for having that capability IRL?

 

It isn't classified. It does have that capability, it is an option that you can select.

 

In RWS/TWS mode the contacts on radar are always the same size, disregard of targeting a chopper or a An-30. Is it suppose to work like that? On the DCS Flanker, contacts have different sizes.

 

Yes, there is no differentiation or rather, no hint of differentiation in the RWS target representation.

 

Best PRF setting to keep STT lock from failing?

 

You want MPRF outside of 15nm if the target is turning cold, but that too has a limited range.