April 25, 2011

Because of Falcon

The Falcon is a very infamous ship. The presence of a single one can turn the tide of battles, despite its looks.

Oh. Um... It cloaked. Dammit. Where'd it go? Come out, come out. It can't have gone too far...

I'm really sorry, I wanted to show you a Falcon, and it went and-- OH GOD THERE IT IS AND IT'S JAMMING ME AUGH.

Well then, let's try this again. So, what does a Falcon do? Well, it cloaks for one thing. And for another, it applies

Electronic Countermeasures
Or ECM, or jamming, for short. Whenever a ship is jammed, it is simply unable to target. Its drones continue to operate as they were, but no targeted attack (guns, non-FoF missiles, electronics, etc) works, as it has no lock. This makes ECM a very potent form of electronic warfare. But... how does it work?

Jammers come in 5 different types. The first, usually identified by a "multispectral" ("multispec" for short) designation, works equally well against any target. Unfortunately, in general it doesn't work as well as the others, has shorter range, and requires more capacitor to run.


Multispectral ECM
This module is usually used on ECM-focused ships that do not have the available mid slots to fit up large amounts of specialized jammers (such as the Griffin, or Kitsune). Specialized jammers can be much more useful, on the other hand, as they are racial-based:

From left to right: white noise generator, spatial destabilizer, ion field projector, phase inverter

Each of these are about 3 times as effective against their target race of ships than against the other 3 races, and about 1.5 times as effective as an equivalent multispectral ECM. But, what do I mean when I say effectiveness? How does ECM work?

First, let's throw out the names of each race's sensor type:
  • Amarr - Radar - How to remember: backward and inflexible society leads to backward, simple, and inflexible radar tech; the jammer is golden/yellow, like their ships.
  • Caldari - Gravimetric - How to remember: Caldari are businessmen, aka "fat cats", and fat things generate gravity; the jammer is blue, like their ships.
  • Gallente - Magnetometric - How to remember: Gallente girls are usually the most "attractive", aka magnetic; the jammer is aqua, the only non-primary color jammer, because Gallente are fabulous that way.
  • Minmatar - Ladar - How to remember: laser radar, because while backward, the Minmatar are more badass than Amarr; the jammer is red, the color of badassery (and of some of their ships).
Now, let's move on to how it works. Say a Griffin is trying to jam out my Rifter.

In essence, jamming works via random chance, and comparison of the jamming strength of each individual jamming module with the sensor strength of the target ship. This means we need to look at numbers. So let's look at numbers.

The Rifter has a Ladar strength of 8 points. At first, the Griffin is using a flat tech-1 multispectral jammer. Since his skills are perfect, he gets 4.37 jam strength. This means that he has a 4.37/8 = 54% chance of jamming my Rifter. That's... not too good.

So, instead, he swaps out for a Phase Inverter, which gives him 6.56 jam strength. He now has 6.56/8 = 82% chance of jamming me. Yes, the racial vs multispec jams make that much of a difference.


But, the Griffin has 2 other mid-slots that could fit ECM. What if both of them had Phase Inverters (he was extra-ready to kill Minmatar ships)? What happens if he uses his 3 inverters and the multispec on me? Time for some probability calculations!

There are 3 jammers with 82% chance to jam me, and 1 with a 54% chance to jam me. Or, in other words, there are 3 jammers with a 18% chance to not jam me each, and one with a 46% chance to not jam me.

In order for him to jam me, only one of those needs to work. Conversely, in order for me to survive the jam cycle means they all have to fail. The chance that a bunch of random chances will all happen is the product of all of them. Therefore, the chance all the jams fail is:
0.18 * 0.18 * 0.18 * 0.46 = 0.00268 = 0.268%
Therefore, for him, the chance I get jammed is 100%-0.268% =  99.732%. That's pretty good.

So good that there is a term for it: permajam. When your jamming is so good that the target ship will never realistically be able to regain its sensors, you get cake. Lastly, for those more mathematically minded:

ECM drones work on the same concept: the drones have jamming strengths in their attributes, and if the calculation works out in their favor the target's targeting is dropped. Unfortunately, drones do not jam as ships do, but only drop targeting (and the victim can start re-targeting immediately).

Edit: after messing around with ECM drones more, it appears I was wrong. They jam as if they were weaker Multispectral jammers. And are awesome. For reference, their jam strengths are: Light (Hornet EC-300) = 1; Medium (Vespa EC-600) = 1.5; Heavy (Wasp EC-900) = 2.5.  

There is also another ECM type of modules, ECM Burst modules, which act as multispectral jammers that drop the targeting of every ship in a distance close to you (similar to how smartbombs work). They use the same concept.

Lastly, there exist Electronic Counter-countermeasures (ECCM) modules, and Sensor Backup Arrays, both of which increase your ship's sensor strength so as to make it harder to get jammed. But, that's pretty much it! You now know how jamming works.

Oh and for the record? That Falcon is still there, and all my poor Rifter sees is

You are already managing 0 targets, as many as your ship's electronics are capable of.
It's going to be a long day.


  1. I hate ECM with a passion :) Nice write-up.


  2. Late to the party but I think this might be the best ECM explanation I've ever seen. Fantastic job.