Questions about AIM-7F/M/MH irradiation

[EcceHomo]

Starting with the AIM-7F, the missile's post-launch irradiation can be accomplished by the airborne pulse Doppler radar antenna, eliminating a separate CW irradiator (a interrupted cw guidance scheme). Can CW warning lights be used in CW or interrupted cw ?

[BeastyBaiter]

I think you maybe trying to massively over complicate it. Process for AIM-7 in game is lock target, shoot and keep locked till missile hits or misses. There is nothing else to it.

[EcceHomo]

I think you maybe trying to massively over complicate it. Process for AIM-7 in game is lock target, shoot and keep locked till missile hits or misses. There is nothing else to it.

 

Maybe, I want to talk about the RWR alarm after AIM-7M launch. Whether the AIM-7M alarm of ICW should be different from that of CW missile.

[VFA41_Lion]

What are you talking about? The AIM-7 missile does not radiate. It is guided by the launching aircraft's radar.

[BeastyBaiter]

Ok, I think I understand what you're asking now. I couldn't previously figure out why you mentioned rwr functions when talking about firing sparrows. To answer your apparent question, your own missiles should not trigger the RWR since it shouldn't see your own radar emissions. If this isn't the case, it's a bug. You will get launch warnings for friendly aircraft. I believe this is working as intended. There is an RWR filter knob near the power button for it. This may allow for removing NATO aircraft missile launch warnings, I have not tried it.

Edited September 2, 2018 by BeastyBaiter

[Alfa]

No he is asking whether launch warning indication on opposing RWR looks the same for an AIM-7 version using CW(Continuous Wave) illumination as for one using PD(Pulse Doppler) illumination.

[EcceHomo]

No he is asking whether launch warning indication on opposing RWR looks the same for an AIM-7 version using CW(Continuous Wave) illumination as for one using PD(Pulse Doppler) illumination.

AIM-7F（CW and interrupted CW），AIM-7M/MH（only interrupted CW）.

[Alfa]

AIM-7F（CW and interrupted CW），AIM-7M/MH（only interrupted CW）.

 

Its not "interrupted CW", but pulse doppler illumination. But yes the AIM-7F is compatible with both CW and PD, while the AIM-7M(and further) are PD only.

[EcceHomo]

Its not "interrupted CW", but pulse doppler illumination. But yes the AIM-7F is compatible with both CW and PD, while the AIM-7M(and further) are PD only.

This is the use of high PRF target irradiation, in some Chinese papers called "interrupted CW", it is different from the classical continuous wave (completely using continuous wave).

 

[Alfa]

This is the use of high PRF target irradiation, in some Chinese papers called "interrupted CW", it is different from the classical continuous wave (completely using continuous wave).

 

Sorry I cannot read Chinese, so I cannot comment on the bit in your attachment - at least I would need the text in a way so that it can be pasted into a translator :)

 

Anyway, the mechanically scanned pulse doppler fighter radars we talk about here(such as the F-15's APG-63) use either a separate CW illuminator(for early AIM-7 versions with conical scan seekers) or pulse doppler illumination(for later AIM-7 versions with monopulse seekers), which is "time shared" with the radar's "normal" operation.

 

The AIM-7F is a special case, since it can use both types of illumination - I guess as a transitional effort(making the weapon compatible with both old and new radar configurations).

 

"Interrupted CW" is something different - its a form of CW used e.g. for SAM systems and (I believe) in combination with electronic scanned phased array tracking radars in order to control multiple SARH missiles against multiple targets simultaneously.

[EcceHomo]

Sorry I cannot read Chinese, so I cannot comment on the bit in your attachment - at least I would need the text in a way so that it can be pasted into a translator :)

 

Anyway, the mechanically scanned pulse doppler fighter radars we talk about here(such as the F-15's APG-63) use either a separate CW illuminator(for early AIM-7 versions with conical scan seekers) or pulse doppler illumination(for later AIM-7 versions with monopulse seekers), which is "time shared" with the radar's "normal" operation.

 

The AIM-7F is a special case, since it can use both types of illumination - I guess as a transitional effort(making the weapon compatible with both old and new radar configurations).

 

"Interrupted CW" is something different - its a form of CW used e.g. for SAM systems and (I believe) in combination with electronic scanned phased array tracking radars in order to control multiple SARH missiles against multiple targets simultaneously.

 

 

 

You are talking about pulse doppler illumination, which uses Doppler shift to determine the target and solve the target information from the echo. In the airborne pulse Doppler radar system, there is no separate continuous wave transmitter, and the PD radar in HPRF is used instead of continuous wave for illumination. In order to distinguish between the two illumination systems, some people divide them into classic continuous waves (duty cycle is 100%) and discontinuous continuous waves (HPRF duty cycles are 30%-50%). Therefore, it is necessary to improve the original continuous wave missile to adapt to the new lighting system. The monopulse seeker you mentioned is not a beam describing the illumination, but a seeker technology that represents the new antenna technology.

The ICW you mentioned should be semi-active with intermittent illumination. The specific example is the end illumination of SM2 (which uses mid-range command guidance + semi-active end).

Original Chinese：

另一个收、发可以共用一个天线的方案是跟/照都用同一个脉冲多卜勒波形,取消CW发射机,当然也就没有交连问题了。在60年代初期国外曾对以往的各种全CW系统都改装过。此时可使用无距离选通的高工作比(30~50%)脉冲多卜勒,并用纯常的TR开关来保证隔离度,但在接收机信号处理电路中的某一点上,只选择利利用了脉冲多卜勒频谱中的那条中心谱线。脉冲重复频率要选得很高,使足以不产生多卜勒模糊,因此当接收机选出那条中心谱线时的频谱就和CW情况下完全相同。。。。。。在这二种情况下,接收机和倍号处理的其它部分是与CW系统相同的。这种波形有时也称仵间断式连续波,以区别于带多个距离门的经典冲多卜勒波形,因为在后一情况下,弹上往往采用主动式脉冲多卜勒波形。