I was looking to understand jamming and ECM in general, how does it work in the game, the forums have some good posts on this but then ... why not ask the GE itself? In Harpoon I can do what ELINT officers can only dream of, invite the Russians to Red Flag!

Lets come over the Atlantic for a friendly what have you got! Red can have Keflavik, Blue is flying from Kinloss. Bring everything you have. The SE sets up the bases nicely, we are all friends but better ready as many Ferry loadouts as possible. Additionally Air Marshall General Bernard Show All will also keep a sharp lookout for anyone giving in to old instincts.

ELINT corps are strapping on ESM gear everywhere, the GE is already being trailed by a heavy load of "-l ecm" and "-l radar" debug flags and a hungry looking Perl script is ogling Miss Logfile so much so she can't help blushing.

Lets get started.

Maximum radar detection ranges

Tony has posted an excel table to calculate maximum detection range based on target RCS and radar range, but the older battlesets have their embedded DB (RCS) and playing is anyway better than calculus.
RCS values were rough cut in the classic and HDS battlesets, practically 3 RCS value was used to cover everything flying, small, medium, large. This is soon confirmed by the aircraft parading in front of the AEW radars.


ACMI pods are spurting data, log file is being crunched and we got results.

HDS1 AEW detection ranges


The first surprise, the APY-1 radar on the E-3 does not have LDSD capability, has 50% reduced range against off altitude targets.
Same for the IL76 Mainstay, no LDSD.


For an up to date picture I switch to the EC2003 GIUK battleset.
RCS values are more accurate here, there is more to crunch.

EC2003 GIUK AEW detection ranges
Blue sends up an E-2D Advanced Hawkeye,


Red flies out the A-50U Mainstay, both have LDSD.


Fighters pilots are also eager to test their gear.
EC2003 GIUK Fighter radar detection ranges

US Fighters


Russian Fighters


I wonder, was the LDSD flag removed from the Blue AEW planes to balance the game?
The original GIUK and NACV had it.
Check up of Blue AEW LDSD with few battlesets (feel free to extend it!):


ECM (Jamming) vs radar detection (part 1)

The Red Flag exercises confirm (reveal?) that the GE models two type of active ECM.

• The first type is "direct" jamming. It is also called "barrage" ECM in the literature. This is when the ECM gear is attempting to overwhelm the radar's emissions directly with brute force.
• The other is "escort" jamming. This covers different types of Deceptive ECM techniques when the EW plane protects other escorted planes by falsifying their returned radar signals (skin returns). The protected planes need to be in the vicinity of the EW plane for this to be effective.

The following Red Flag missions will attempt to determine the effective active ECM ranges of the radar and EW planes and the size of the area an EW escort is able to cover.
The game models ECM effect by degrading the effective detection range of the jammed radar. This is the only effect, for example probability of detection (pD) is not affected by ECM.

Which are the active ECM pods?
These are listed in the loadouts with TARGET=RADAR and have positive RANGE, that is RANGE is not "HORIZ" and not 0. They also have a HIT% but more on that in a separate post.

The GE calculates with this ECM RANGE for both for direct and escort jamming, but in different ways.

• To be able to jam a radar directly the EW a/c has to be closer than ECM RANGE to the radar.
• To be able to jam radar detection of escorted a/c the EW a/c has to be closer than ECM RANGE to the escort. The EW a/c and the target a/c also both has to be inside the radar's range.
  • The distance between the EW and radar aircraft can be much greater than that. Maximum allowed distance to radar for escort jamming is probably 10 x ECM RANGE.

Tu-16J direct ECM of an E-2D Hawkeye
On the first flight of the day an E-2D Hawkeye will be jammed by a Badger EW plane.
The Hawkeye loiters in place, tracking a Tu-95K Bear bomber loitering 165nm to the West from the Hawkeye. The Bear has huge RCS and loiters on high, the Hawkeye can effectively detect it at it's maximum 400nm range.
The Badger will merge with the Hawkeye closing from the North with ECM active. The Badger starts from 407nm out, outside of the Hawkeye's radar range. The ECM RANGE of the Badger's Buket ECM gear is 60nm.


ELINT will measure the effectiveness (maximum effective range) of the Hawkeye's radar against the Bear as it is degraded by the Badger's jamming.
The expectation is that the Hawkeye will detect the jamming as soon as the Badgers enters into it's radar range (indicated by the yellow lightning bolt) but this will have no effect on the detection of the Bear until the Badger closes within direct ECM range. (The Bear is outside of the escort range of the Badger, e.g. no escort/standoff jamming effect.)

This is confirmed, the skin return of the Bear is strong enough to detect it out to 400nm all the way until the Badger closes within 60nm of the Hawkeye. Then the barrage starts and radar is degraded as the Badger closes, drops down to 52nm. (52nm is 13% of the 400nm, this is a rock bottom constant, more on that later.)


The graph shows that between 60-80nm (and further out) there is no degradation.
It starts at the 60nm distance, kicks in at 40nm and reaches it's maximum at 14nm.

Next flight will be about testing out escort jamming.
To be continued.
Jump to part 2

Fantastic, keep em coming!

Very, very impressive :)

And the game keeps live and realistic, thanks Grumble!!!

Thanks guys! EW started with a question which turned into a hobby and now, I think, this is an obsession. I already got the escort jamming data, just need to find the time. But more to come soon.

One of the jobs that we have never had ample time or manpower to complete was the documentation to support this sim.

 

So you're certainly helping to flesh out the stuff we've had to try and explain piecemeal for years now. Thanks!

I should add that I will be most interested in hearing whether you think some of the ECM values (some of them longstanding) should be adjusted (upward or downward), and whether that will positively affect game play.

I should add that I will be most interested in hearing whether you think some of the ECM values (some of them longstanding) should be adjusted (upward or downward), and whether that will positively affect game play.

About this point I have retrieved some ECM comparatives and values along the years. Perhaps has come the time to clean up and put in common the data the next weeks ...

ECM (Jamming) vs radar detection (part 2)

 

Second day at the Red Flag, I am going to take a closer look at escort jamming.

I intend to test out other EW aircraft too but for now lets stick to the E-2D Hawkeye and the Tu-16P Badger J, two of the most powerful radar and EW gears.

For now I intentionally exclude factors as line of sight (LOS) and weather so it is easier to deduce EW rules, however LOS will have to be tested soon.

 

Tu-16J escort ECM (a.k.a. standoff jamming) of E-2D Hawkeye radar (EC2003 battleset)

 

The direct jamming test flight showed that the appearance of the yellow lightningbolt does not mean that the marked radar is "jammed" in general and in all directions. The jammer has to be (very) close to the radar or to the plane it wants to mask. I'm going to test now how far does the coverage of the Badger's ECM reach.

 

The Hawkeye is once again loiters over the Atlantic, our Badger some 270nm North of it, loitering too, ECM active. The Tu-95 Bear ELINT target will fly towards the Hawkeye from +400nm out on the axis of the Badger. The Bear will pass by the Badger as close as possible barring an accident.

 

 

And here is the ELINT data.

 

• The negative half of the X axis shows when the Bear is further out than the EW Badger, the positive half is when the Bear has passed the Badger and is between it and the Hawkeye.
• This radial slice of the ECM "bubble" is asymmetric, stretches to -28nm away from the radar (back lobe) but only to +10nm towards the radar (main lobe). The escort bubble is also smaller than the direct bubble, remember the Badger's ECM range is 60nm. It can not be seen on the graph but the log shows that the jamming actually starts at 59nm from the Badger, but it has no practical effect that far from the ECM source, the radar burns through outside of the bubble.
• The maximum ECM effect, that is the degradation of the radar range in this case is ~30%, the Bear closely escorted by the Badger would only be detected by the Hawkeye at 272nm instead of 400nm.
• The escort ECM decreases the radar's effective range roughly with a proportion two times the fraction of ECM range to the radar's maximum range.
• E.g. the Badger's ECM range of 60nm is 15% of the 400nm range of the radar, so escort jamming can reduce the max detection range by 30%.

For the second test the Bear will pass by the EW Badger perpendicular to the Badger-Hawkeye axis.

 

 

and the data:

 

• The tangential slice of the bubble is symmetric, as expected.
• It is 17nm wide on both sides.
• Maximum ECM effect is fortunately the same when we were moving radially.

We can draw the ECM bubble as this:

 

 

Next post I will send up other EW and radar birds.

To be continued.

Wow! Thanks Grumble!

ECM (Jamming) vs radar detection (part 3)

 

Lets take a look at some other Red Blue combinations.

The test flights use the same arrangements, direct jamming and escort jamming with radial and tangential pass of radar targets over the jammer.

 

HDS1 EF-111A Raven EW vs AEW IL-76TD Mainstay

 

IL-76TD - Mainstay AS radar - 250nm

EF-111A - ALQ-99 ECM Pod - ECM Range 50nm

Direct ECM

The Mainstay is tracking F-111F Aardvark (large), Tornado GR.4 (medium) and F-22 (small) targets while the Raven is closing in with ECM active.

 

Escort ECM - targets closing

The Mainstay is tracking the same targets (F-111F, Tornado GR.4, F-22) closing to the AEW plane. The Raven is between them, the targets pass over it.

Data

 

Escort ECM - targets crossing

The targets are flying over the Raven perpendicular to the EW-AEW axis.

Data

 

The EF-111A escort ECM bubble

front lobe 10nm

back lobe 21nm

side lobes 13nm

 

EC2003 EA-18G Growler EW vs A-50U Mainstay

A-50U Mainstay - Shmel M - 310nm

EA-18G Growler - ALQ-99 ICAP III pod - ECM Range 50nm

Direct ECM

 

Escort ECM - targets closing

Anomaly detected! ( ME2)

There are strange spikes on the graph when the target is behind the Growler. The Growler produces these consistently, also these are not byproducts of the "detection gear", the very least the anomalous detection ranges can be seen in the raw log files.

I first thought these are somehow related to the fact the the Growler has fighter radar, e.g. no 360 search and it is loitering, however the spikes appear at 2 minutes interval while loitering would induce 3 minutes cycles.

Here is the raw data of the graph for the interested:

 

I did a cross check, here the targets were loitering and the Growler was flying away from the radar.

The spikes are gone! Could this still be related to the loitering?

 

Escort ECM - targets crossing

No anomaly. This contradicts the theory that the Growler's jamming effect would be dependent on the EW-radar or EW-target aspect.

 

The EA-18G escort ECM bubble

front lobe 8nm

back lobe 25nm

side lobes 13nm

 

EC2003 Su-24MP Fencer F EW vs US Fighter radars

Direct ECM

Max detection ranges for US fighters against Su-27 while under barrage jamming from a Fencer F.

Target will also need to hide below LOS or it will be detected well before ECM can significantly reduce the radar range, even with escort jamming effect added. Well, with the exception of the F-16C.

**Hm, after a good night's sleep I need to reconsider this, better, lets send out the boys and try it, see next post.

 

To be continued.

Wow!

ECM (Jamming) vs radar detection (part 4)

 

I was ready to write off barrage jamming as a useful tool since the EW aircraft has to approach the radar well within it's detection range before the barrage can be started, but I did not consider the parallel effect of escort jamming. As soon as the jammer is within the maximum theoretical range of the radar escort jamming is already affecting it. This can be very effective against fighter radars due to the smaller output power (range) of these.

A Su-24 Fencer F EW aircraft escorting a Su-27 Flanker and Yak-141 freestyle will try approaching patrolling blue fighters.

 

HDS1 Su-24MP Fencer F vs F-15C Eagle

 

F-15C - APG-70 - 120nm

Su-24MP Fencer F - Fencer ECM Pod - ECM Range 40nm

The Fencer's ECM range is 1/3 of the Eagle's radar range so it can degrade it's performance with more then 2/3 !!

The red group approaches from outside the Eagle's radar range then closes within direct ECM range.

(In HDS1 the Freestyle and the Flanker has the same RCS (medium) so the graph shows just the Flanker.)

The Flanker's medium size means that the APG-70 can ideally detect it from max 80nm only.

 

 

Pretty scary. In the game the Eagle first detected the Fencer at 27nm due to the 30 second detection cycle and loiter heading changes.

 

HDS1 Su-24MP Fencer F vs JAS.39 Gripen

JAS.39 - PS-5/A - 85nm

Su-24MP Fencer F - Fencer ECM Pod - ECM Range 40nm

 

The Fencer's ECM obliterates the Gripen's radar already from standoff range. This effect is fortunately limited to targets in the close vicinity of the EW Fencer.

 

The scariest in all this is that neither the Gripen nor the Eagle has ESM. The only sign of the approaching red group is the lightningbolt, no Staff Assistant, no uncertain ESM detection until the Fencer warps in at 23nm!

I've just added ESM to the todo list.

 

To be continued.

Casually I'm reading today a very detailed book, "Tupolev Tu-22 Blinder", by Sergei Burdin and Alan E. Dawes, Pen & Sword 2006. On page 114 and 115 showing true world ECM range numbers very similar to employed in Harpoon in the descripted Tu-22P ECM systems:

SPS-4M/5M/6 range against enemy radars with 100% efectiveness: 54 to 70 nm.

SPS-77 range against enemy radars with 100% efectiveness: 27 nm.

SPS-44 Buket suite of Badger-J: range against enemy radars with 100% efectiveness: 81 nm.

(a lot of interesting points in the book, including mention to the Krivak I FFG Storozhevoy (Baltic Fleet) mutiny attempt in 1975 and Blinder interception, but at last bombed by Su-17 or Yak-28, page 144. Another point: training in attack formatión of 31 Tu-22K, page 179. Use of Tu-22PD Blinder-E jammers in Afghanistan against the Pakistani defences and F-16 to protect the Backfire incursions, page 186).

Here are the actual GE radar LOS values I got as byproduct running the radar detection scripts.
Shows that actual GE data has some deviation from the LOS values documented in the HUCE manual (page 63).

Red values show deviation, bold where it is significant.

Attached the test scenario and the data extract in excel, for the interested.

 

LOS.zip