Questions regarding Jamming strength and frequencies

[+HomeFries 29]

I've started work on the EA-6B Prowler variants for the next A-6 Superpack. So far I'm planning on doing the following:

• EA-6B_71 (the original prowler)
  
• EA-6B_73 (EXCAP)
  
• EA-6B (3W default, which assuming the 1979 timeline corresponds to the ICAP I)
  
• EA-6B_84 (ICAP II)
  
• EA-6B_05 (ICAP III)
  

 

The toughest part of this equation is determining the values for ECM. This problem is complicated by the following:

1. The 3W Prowler has a jam strength of 120 and jams freqs 1-20.
   
2. The ICAP II Prowler by Hawker/Agemmenon & 331KillerBee has a jam strength of 90 and jams freqs 0.1-10.
   
3. FastCargo's EF-111 Raven has a jam strength of 90 (no frequency range listed).
   

I realize that both the EF-111 and the Hawker/Agemmenon & 331KillerBee prowler were released before SF2NA, and SF2NA added ships with search/track/FC radars in the 15 freq range. However, 120 seems too strong for the ICAP I. At the same time, I don't want to nerf the default 3W prowler by 25% and possibly upset any balancing, especially since the Iceland campaign is hard enough as it is.

 

The other question I have is the level of ECM modelling in SF2. I'm assuming that the game engine compares jamming frequencies to platform frequencies, and if they overlap then the jammer strength is linearly compared with the radar strength with burn through distance depending on the differences in strength. Could somebody confirm or clarify this for me?

 

Finally, many of the ALQ-99 upgrades were in the form of being able to simultaneously jam additional frequencies. Is this modeled with any fidelity in SF2, or does the game engine assume barrage jamming of all frequencies at full strength? Could the increase in simultaneous jamming be modeled with slightly increased strength to abstractly represent the ECMOs being able to barrage a narrower frequency band?

 

Here are my proposed values for the prowler variants. Please provide your inputs and/or spitballs.

EA-6B_71

[ALQ99]
SystemType=ECM_JAMMER
JammerType=NOISE_JAMMER
JammerStrength=65.0
MinFreq=2.0
MaxFreq=8.0
CanJamCW=FALSE

I don't want to go less than 2-8 (the A-6B ECM freq range), and strength 65 seems a fair increase over the A-6A/B ECM

 

EA-6B EXCAP

[ALQ99A]
SystemType=ECM_JAMMER
JammerType=NOISE_JAMMER
JammerStrength=65.0
MinFreq=1.0
MaxFreq=13.0
CanJamCW=FALSE

The ALQ-99A on the EXCAP reportedly covered twice the frequency range of the original; this isn't a 2x increase, but it's fairly close without being able to cover some of the ship radars introduced in SF2NA.

 

EA-6B ICAP (3W Default)

[ALQ99C]
SystemType=ECM_JAMMER
JammerType=NOISE_JAMMER
JammerStrength=120
MinFreq=1.0
MaxFreq=20.0
CanJamCW=TRUE

Here's where it gets trickier. For reasons specified earlier in this post, I'm hesitant to reduce the strength or frequency range of the default prowler. However, a near 2x increase in jammer strength seems too much. Likewise, the ALQ-99 didn't expand its frequency range again until the D model used with the ICAP II.

 

EA-6B ICAP II

[ALQ99D]
SystemType=ECM_JAMMER
JammerType=NOISE_JAMMER
JammerStrength=120
MinFreq=1.0
MaxFreq=20.0
CanJamCW=TRUE

Identical in its entry to the ICAP I, though this time the values seem more representative of reality. Of course, we now have an ICAP II with a strength of 120 comparing to the strengths of 90 for both the Hawker/Agemmenon & 331KillerBee prowler and FastCargo's EF-111.

 

The ICAP III entry would be identical to the ICAP II, as both use the ALQ-99D. I'm considering scrapping the ICAP III variant altogether, as the tactical updates for the ICAP III seem to focus on mission planning and communications jamming, neither being of particular importance in SF2.

 

Please provide your comments and suggestions.

Edited June 9, 2012 by HomeFries

[MigBuster 2,884]

Actual coded implementation of how it works is probably something Thirdwire would have to answer.

 

 

ECM values have been derived through trial and error - and are probably specific to a certain patch level - so that might have been set up against 3rd party weapons only for example.

 

Over the years internal coding has changed missile behavior and frequencies and CW considerations only came in with SF2 - so you would be looking at seeing what values are best for the current patch based on what you are looking to achieve.

 

And is that correct - all ALQ-99s have had Noise/barrage Jamming modes only?

[+HomeFries 29]

And is that correct - all ALQ-99s have had Noise/barrage Jamming modes only?

I'm not an EW expert by any stretch, but I would find it hard to believe that the ALQ-99 was limited to noise and barrage jamming. In fact, later variants of the 99 are considered "smart" jammers, which would indicate to me that they would vary modes and hop frequencies to prevent against HOJ missiles. My supposition was only based on how I envision that 3W simplistically models ECM.

 

I figure the game models it like this:

• If you have a deceptive jammer, the ECM system will put its entire strength into jamming the highest priority threat within its frequency range. This makes sense from a tactical defensive perspective without unbalancing the game.
  
• If you select a noise jammer, the ECM system will apply its full strength over the entire frequency range (something physically impossible, but it keeps the algorithm simple and works for gameplay).
  

 

Of course, you bring up an excellent consideration, MigBuster. What if the later model ALQ-99 consisted of two ECM systems, with deceptive and noise jammers. If the gameplay would be affected, this could protect the prowler tactically as well as provide EW suppression for the package. Definitely some questions to ask at the 3W forum.

[MigBuster 2,884]

In game the ALQ-131/ 119 are dual mode - the actual implementation needs to be tested really - barage/noise jamming will give a HOJ target in some instances - and a lot of the missiles had this functionality (including Sa-2s in Nam) so the weapons do have a HOJ box - but again how it works not sure - might be basic and I don't think frequency hopping is there. - although I might be able to set up an ALQ-87 that just jams Fan song guidance frequencies - so thats not a bad level.

 

 

See here

 

http://combatace.com/topic/57249-ecm-jammers-in-sf2-for-sf2-kb/

Edited June 9, 2012 by MigBuster

[+HomeFries 29]

Roger all.

 

I actually reviewed that Kb thread just after posting my reply, and was thinking the same thing about implementing a combined jammer for the ICAP II, or possibly putting the ICAP III (or ICAP II Blk89A) back on the table.

 

EDIT: While we're on the subject of HOJ, I couldn't find any entries in the FanSong or BarLock data files, nor any of the SA-2L datafiles. Is there a particular entry I'm looking for?

Edited June 9, 2012 by HomeFries

[MigBuster 2,884]

You want the actual missile - the SA-2L is just the launcher.

 

Its a tick box on the weapons editor - you will need to extract and open weapondata.ini to see the stock weapons now.

[+HomeFries 29]

Ah yes, the weapons database. Was too busy thinking in objectland...

 

Thanks. I'll give it a look.

[Fubar512 1,350]

All of you realize that "dual_mode" is also available as a Jammer Type, right?

[+HomeFries 29]

Thanks, Fubar. I was wondering what the proper nomenclature was for it; now I can put this in for the D and later.

[+HomeFries 29]

Everybody,

 

I hit the motherlode of information the other day, and had a breakthrough with my Prowler datafiles.

 

Here's a graphic of the bands covered by the ALQ-99, as well as the corresponding frequencies.

 

The "Standard" (i.e. original) EA-6B/ALQ-99 could cover bands 1/2, 4, and part of 7. Therefore, I went with the following values:

[ALQ99_Low]
Name=AN/ALQ-99
SystemType=ECM_JAMMER
JammerType=NOISE_JAMMER
JammerStrength=65.0
MinFreq=0.07
MaxFreq=0.3
CanJamCW=FALSE
InterfereRWR=TRUE

[ALQ99_Mid]
Name=AN/ALQ-99
SystemType=ECM_JAMMER
JammerType=NOISE_JAMMER
JammerStrength=65.0
MinFreq=0.5
MaxFreq=1.0
CanJamCW=FALSE
InterfereRWR=TRUE

[ALQ99_Hi]
Name=AN/ALQ-99
SystemType=ECM_JAMMER
JammerType=NOISE_JAMMER
JammerStrength=65.0
MinFreq=2.5
MaxFreq=3.8
CanJamCW=FALSE
InterfereRWR=TRUE

[ALQ100]
Name=AN/ALQ-100
SystemType=ECM_JAMMER
JammerType=DECEPTIVE_JAMMER
JammerStrength=35.0
MinFreq=2.0
MaxFreq=8.0

[ALQ41]
Name=AN/ALQ-41
SystemType=ECM_JAMMER
JammerType=DECEPTIVE_JAMMER
JammerStrength=35.0
MinFreq=8.0
MaxFreq=12.0
CanJamCW=FALSE
VisualBlindArc=10,11,12,1,2
VisualRestrictedArc=3,9

As you can see, I created 3 separate Noise Jammers identical in capability, but covering separate bands. I also added the ALQ-41 and ALQ-100 DECM suites, though I have no idea whether VisualBlind/RestrictedArc works with ECM as it does for radars This is important since the Q-41 only covers the aft quadrant of the aircraft. If anybody can clue me in on that, I would appreciate it. Also, is there a way to make an ECM system interfere with the onboard radar as well as the RWR?

 

For the EXCAP, the bands covered by the ALQ-99A through 99C are 1/2,4,5/6,7(partial), and 8/9. I left the ALQ-100 and ALQ-41 intact, and made the following changes to the ALQ-99:

[ALQ99_Low]
Name=AN/ALQ-99C
SystemType=ECM_JAMMER
JammerType=NOISE_JAMMER
JammerStrength=75.0
MinFreq=0.07
MaxFreq=0.3
CanJamCW=FALSE
InterfereRWR=TRUE

[ALQ99_Mid]
Name=AN/ALQ-99C
SystemType=ECM_JAMMER
JammerType=NOISE_JAMMER
JammerStrength=75.0
MinFreq=2.5
MaxFreq=3.8
CanJamCW=FALSE
InterfereRWR=TRUE

[ALQ99_Hi]
Name=AN/ALQ-99C
SystemType=ECM_JAMMER
JammerType=NOISE_JAMMER
JammerStrength=75.0
MinFreq=4.0
MaxFreq=20.0
CanJamCW=FALSE
InterfereRWR=TRUE

I also increased the JammerStrength to 75 to account for the exciter, which significantly reduces the ECMO's workload, thereby providing an arbitrary increase in capability.

 

The ICAP-I is where things start to get interesting. It appears that the ICAP-I is the model physically represented by the 3W EA-6B, as it has both the ALQ-126 "beer can" on the back of the tail and "sawtooth" on the refueling probe, as well as the doppler radar on the belly (which was removed with the ICAP-II). This also meshes with the 1979 timeframe of SF2NA, at which time ICAP-I was state of the art. However, the capabilities modeled are those of the ICAP-II (and even the ICAP-II Blk 89 in terms of ECM).

 

The ICAP-I and the corresponding ALQ-99D introduced digital receivers and integrated computer controlled jamming systems, and reapportioned the ECMO workload so that ECMO 2 and 3 (the "kids in back") were responsible for tactical jamming. The work-leveling and digital integration prompted the increase in JammingStrength to 90, which also matches up with FastCargo's ALQ-99E, which was near-identical in capability to the Q-99D (albeit with fewer bands covered). Finally, since the ALQ-99D covers bands 1/2, 4, 5/6, 7 (partial),8, and 9/10 I have once again split the Noise Jammer into three separate, equally capable systems covering different freqency ranges.

 

To this end, I have significantly nerfed the 3W default ECM suite (JammerStrength=120, Freq from 1-20) to bring it more in line with the ICAP-I capabilities. However, I did add the ALQ-126A DECM suite, so the prowler isn't significantly weaker across the board.

[ALQ99_Low]
Name=AN/ALQ-99D
SystemType=ECM_JAMMER
JammerType=NOISE_JAMMER
JammerStrength=90.0
MinFreq=0.07
MaxFreq=0.3
CanJamCW=TRUE

[ALQ99_Mid]
Name=AN/ALQ-99D
SystemType=ECM_JAMMER
JammerType=NOISE_JAMMER
JammerStrength=90.0
MinFreq=2.5
MaxFreq=3.8
CanJamCW=TRUE

[ALQ99_Hi]
Name=AN/ALQ-99D
SystemType=ECM_JAMMER
JammerType=NOISE_JAMMER
JammerStrength=90.0
MinFreq=4.0
MaxFreq=20.0
CanJamCW=TRUE

[ALQ126A]
Name=AN/ALQ-126A
SystemType=ECM_JAMMER
JammerType=DECEPTIVE_JAMMER
JammerStrength=40.0
MinFreq=2.0
MaxFreq=12.0
CanJamCW=TRUE

 

This leaves the ICAP-II. I have split the ICAP-II into the Block 82 and the Block 86/89. The differences between the blocks are the enhancements to the ALQ-99F.

 

The biggest jump in capability for the ICAP II was the universal exciter which covered bands 1-9, thereby obsolescing the dedication of individual pods to bands. Additionally, band 7 was now completely covered. As such, the ALQ-99F system is now split into two systems representing separate bands. (1/2, and 4-10). The increase in JammerStrength is justified by the further reduction of ECMO workload by the TEAMS system, which significantly improves response time against known/planned threats.

[ALQ99_Low]
Name=AN/ALQ-99F
SystemType=ECM_JAMMER
JammerType=NOISE_JAMMER
JammerStrength=100.0
MinFreq=0.07
MaxFreq=0.3
CanJamCW=TRUE

[ALQ99_Hi]
Name=AN/ALQ-99F
SystemType=ECM_JAMMER
JammerType=NOISE_JAMMER
JammerStrength=100.0
MinFreq=2.5
MaxFreq=20.0
CanJamCW=TRUE

[ALQ126B]
Name=AN/ALQ-126B
SystemType=ECM_JAMMER 
JammerType=DECEPTIVE_JAMMER
JammerStrength=55.0
MinFreq=2.0
MaxFreq=20.0
DualMode=1
CanJamCW=TRUE

Also note the inclusion of the ALQ-126B, which increases the frequency response of the ALQ-126A and provides 1kW of jamming strength per band. While the TMF F-14 Superpack places a JammerStrength=70 on the Q-126B, I felt that a near-twofold increase in capability from the A seemed too much. This is a gut call with no quantifiable data to back it up (I couldn't find the power output of the Q-126A), so if I'm wrong please let me know and I'll make the correction.

 

And finally, the ICAP-II Block 86/89 (I combined the two because the capabilities are essentially the same). We now have an ALQ-99F that covers the 3 band, now providing coverage over the entire threat spectrum. Therefore, we are back to a single ECM system covering frequencies 0.07-20.0. This version of the Q-99F also provides 1kW per GHz, which IMHO justifies the JammerStrength=120. Additionally, this version of the Q-99F is a "Smart Jammer", which I interpret to be dual mode. The ALQ-126B (also included) is identical to the ICAP-II Block 82.

[ALQ99]
Name=AN/ALQ-99F
SystemType=ECM_JAMMER
JammerType=NOISE_JAMMER
JammerStrength=120.0
MinFreq=0.07
MaxFreq=20.0
CanJamCW=TRUE
DualMode=1

 

Please provide feedback. Likewise, if anybody would like to test the datafiles please let me know since I won't have time to playtest these variants for balance.

 

@Fubar, you also mentioned that "dual_mode" is a jammer type, yet I also saw the logic flag DualMode=1 in the TMF Tomcat. Is one way preferred over the other, or do both entries yield the same result?

[Fubar512 1,350]

@Fubar, you also mentioned that "dual_mode" is a jammer type, yet I also saw the logic flag DualMode=1 in the TMF Tomcat. Is one way preferred over the other, or do both entries yield the same result?

 

There can only be one....and it is Dual_Mode_Jammer as a type.

 

[+HomeFries 29]

Thanks, Fubar. I guess the TMF Tomcats need an update as well...