Some question about AIM-54 and AIM-7？

CW and range differences ??

Was an answer to the post above yours.

Was an answer to the post above yours.

Thanks:)

AIM-7F can be CW/HPRF (PD) illumination, but AIM-7M is only HPRF (PD) illumination. Semi-active data sampling of HPRF (PD) guided by the ATW-54A/C TWS (first illumination, missile memory illumination, hold control until the next illumination).

That's what I thought, thanks.

 

But, then, the maximum launch range should be shorter as the seeker needs to get a lock on before launch, which begs the question if this could (and would) be simulated in DCS? :)

There is also no mid course datalink for any sparrow version before the P.

The missile is launched with a programmed English bias maneuver that will set the missile on a course towards the target and orient the seeker towards it as well.

The seeker is programmed with the measured target doppler frequency and a narrow here around it. The seeker begins to search for the target after the bias maneuver is complete, IIRC, and the seeker is now outside of the interference caused by the launcher's radar.

CW illumination provides significantly less seeker detection range vs PD illumination. The latter can provide illumination powerful enough to out range the missiles aerodynamic range, especially when performed by a large radar like the awg-9 or apg-63.

There is no lock before launch with a sparrow, ever.

There is also no mid course datalink for any sparrow version before the P.

The missile is launched with a programmed English bias maneuver that will set the missile on a course towards the target and orient the seeker towards it as well.

The seeker is programmed with the measured target doppler frequency and a narrow here around it. The seeker begins to search for the target after the bias maneuver is complete, IIRC, and the seeker is now outside of the interference caused by the launcher's radar.

OK, I didn't refresh on the Sparrow variants; just presumed since the AIM-7M supports PD illumination that it also has mid-course guidance to make use of the longer engagement range (kind of like the R-27R does).

I remember the English bias thing, I guess it's a given for all SARH catapulted missiles, but without thinking about it, it seems somewhat unexpected the M variants were still being launched blind hoping that they'll track once they clear the airplane (i.e. without any follow-up guidance towards the target to ensure the proper seeker lock). Reminds me of the MiG-23M and R-23 missiles where they also had interference problems so their seeker was activated 3 seconds after launch, IIRC.

CW illumination provides significantly less seeker detection range vs PD illumination. The latter can provide illumination powerful enough to out range the missiles aerodynamic range, especially when performed by a large radar like the awg-9 or apg-63.

I guess that explains the necessity of the mid-course guidance on the M, but isn't it more susceptible to burning energy due to target course changes using PN all the way?

But, related to the earlier posts, I presume the WCS would still calculate a shorter maximum launch range if CW illumination is used for M (as compared to PD illumination), right?

I remember the English bias thing, I guess it's a given for all SARH catapulted missiles, but without thinking about it, it seems somewhat unexpected the M variants were still being launched blind hoping that they'll track once they clear the airplane (i.e. without any follow-up guidance towards the target to ensure the proper seeker lock). Reminds me of the MiG-23M and R-23 missiles where they also had interference problems so their seeker was activated 3 seconds after launch, IIRC.

I'm not aware of any SARH missile whatsoever that is 'locked on the rail'.

I guess that explains the necessity of the mid-course guidance on the M, but isn't it more susceptible to burning energy due to target course changes using PN all the way?

It moderates guidance constants based on its distance to the target.

But, related to the earlier posts, I presume the WCS would still calculate a shorter maximum launch range if CW illumination is used for M (as compared to PD illumination), right?

Depends on the WCS. The F-15/18 will display the aero cues and a DSR cue for the current target. Depending on what you're shooting at and other factors like altitude, the DSR cue may exceed the aero range or be well within it.

I don't recall the F-14 LAR construction too well unfortunately; but according to the charts, you can expect 30nm+ DSR cue vs a fighter.

It moderates guidance constants based on its distance to the target.

Yeah, something that R-27R is apparently lacking, but still, wouldn't hurt to have it, especially for less powerful radars I guess. Though, reading on the 7P Block I low-level fusing and seeker improvements, perhaps the Block II mid-course guidance was added primarily with extending engagement range against low-level targets in mind (or even cruise missiles)?

Depends on the WCS. The F-15/18 will display the aero cues and a DSR cue for the current target. Depending on what you're shooting at and other factors like altitude, the DSR cue may exceed the aero range or be well within it.

 

I don't recall the F-14 LAR construction too well unfortunately; but according to the charts, you can expect 30nm+ DSR cue vs a fighter.

Does the target RCS size play a role in these cue calculations? I mean, if the RCS is lower, the missile might need some time to get close enough during which the target might have changed course significantly enough.

I don't recall the F-14 LAR construction too well unfortunately; but according to the charts, you can expect 30nm+ DSR cue vs a fighter.

We have data on the LAR construction depending on if CW or PD is used but currently the AIM-7 in DCS doesn't model the different seekerhead options available in the AIM-7 variants so a single range is used for each model of the sparrow.

Yeah, something that R-27R is apparently lacking, but still, wouldn't hurt to have it, especially for less powerful radars I guess. Though, reading on the 7P Block I low-level fusing and seeker improvements, perhaps the Block II mid-course guidance was added primarily with extending engagement range against low-level targets in mind (or even cruise missiles)?

Not sure who still uses the 7P other than as a RIM-7P.

Does the target RCS size play a role in these cue calculations? I mean, if the RCS is lower, the missile might need some time to get close enough during which the target might have changed course significantly enough.

Indeed it does.

I'm not aware of any SARH missile whatsoever that is 'locked on the rail'.

 

 

the French R-530 is

Mirage III RAAF Weapon delivery manual, page 25

can be found here : https://forums.eagle.ru/showthread.php?t=219464

Thanks, I'll check it when I'm able. Is it locked on the rail or tuned on the rail? There's a difference, and all SARH tune on the rail (some might call that a lock, but it's not a seeker lock on the target, but rather tuning to the radar channel).

"[tuning things] … and alerts the pilot by audio signal when the missile has locked-on to the target. [ then a green light switchs on to indicate target in range]"

IRL ( not in DCS, for now ), the S-530D also gives an audio signal ( What for?... )

It's very clear that the old matra is locked on the rail - there is a little more detail on page 39. Even more clear on p61. As for 530D, who knows? It could just be a shoot tone.

Not sure who still uses the 7P other than as a RIM-7P.

Well, I guess that answers my question on the AP being added primarily for low-level targets like cruise missiles then (except that it's apparently primarily aimed at anti-ship missiles and shipborne use).

Can dudikoff or tharos provide some info or link where i can learn what an "english bias maneuver" is or what it does in reference to missiles?

Here you go.

https://folyoiratok.uni-nke.hu/document/uni-nke-hu/aarms-2015-4-papp.original.pdf

You can put 'english bias missile' in google, that should get you a few results.