No reason not to treat it the same. Radar and wifi use the same medium, just on different wavelengths (frequencies).

I thought it did.

Example
---------------
A Radar station 10 Kilometers away sends out a sensor signal that a sensor signal that covers a 50 Kilometer radius.

The runners vehicle is trying to sneak accross the border. It sends out a jamming signal that interferes and blocks the sensor signal.

However the signal from the jamming only has a range of a few hundred meters. So it never reaches the radar station which is 10 kilometers away.

So neither the original sensor signal which was blocked nor the jamming signal which doesn't have the range ever returns to the radar station, making it look the original sensor signal found nothing.
----------------------------

Now my thought was that a rigger who monitoring the signal frequencies using his Electronic Warfare skill would detect the sensor station's signal and adjust his ECM to compensate and use his vehicle skill or infiltration(vehicle) skill (whichever is lower) to allow him to fly close to the terrain to avoid detection.

Meanwhile the opposition would use its Electonic Warfare skill and its sensors and ECCM to try detect any intruders.

So

(vehicle(inflitration) or Vehicle skill) + Electronic Warfare + ECM
vs.
sensor rating + Electronic WArfare + ECCM

(with the possible addition that ECCM dice can only equal the ECM dice they cannot exceed them)

I'm speaking from an SR3 perspective. In SR3, signature is the TN you have to meet to "see" the object in question.

Booklord, let me quote from the rule book, then give the real life explanation as well:

(p. 225)

1. It seems fairly clear that jammers (ECM) can only work on sensors within their range.
2. Jammers work by overwhelming devices of a lower signal rating.
3. If a device (like our huge radar tower) has a higher signal rating, it will not be jammed.

So unless your ECM gear has a higher rating than the sensor array, it's a moot point.

In real life, as I said, ECM works by filling the radio waves with spam. The radio tower WILL notice this. If it doesn't, the ECM isn't working. However hopefully the signature of the vehicle won't be noticed amid all the trash.

I'd love to hear how you think a radio signal can "block" another signal. This really isn't possible. The best you can do is give an artificial echo, so the radar tower gets two echos from the same signal, creating 'ghosts'. Anything else done to block the signal would have to involve physical measures like radar absorbing paint or a sleek design.

This would fly in the face of logic, since it becomes beneficial to have a low level ECM unit, as higher levels would be detected. Remember, the ECM doesn't work on the radio waves, it works on the initial sensor array. If the array isn't within range of the ECM, the ECM has no effect.

This is exactly right, as anyone who has played a modern flight sim should know.

On this I agree, the jammer tech described in SR4 is not ECM. Or at the very least it's ECM at its most rudimentary form. I thought that ECM in SR3 was far more advanced.

Unless of course your ECM has greater signal strength and less range. Or the ECM signal is capable of disrupting the sensor signal by sending out a signal that messes with its wavelength or frequency.

Be careful bringing RL physics into this! I always thought that ECM in SR3 was a technological advancement that we simply don't have today. However in the electronic warfare section of the SR4 book it does say that a runner may:
1) Detect a hidden node
2) Decrypt its signal
3) intercept the signal
and finally
4) edit the signal
If you can do that with a comm signal then you can almost certainly interfere with sensor signals can't you?

Can't you match its wavelength or frequency or something along those lines? Take for example the concept of a "white noise" generator. It disrupts the frequencies that sound travels on and therefore blocks noise within its area of effect. But doesn't overpower them.

But this isn't a modern flight simulator. It's the future some 65 years from now.

It isn't. It still requires the affected sensor to be within the range of the ECM system -- it in fact works about exactly like modern, RL ECM systems. Which, considering SR3s track record with vehicles, is quite astonishing really.

It isn't. There's absolutely nothing special about SR3 ECM.

Too bad so much of the technology is behind current developments, then, eh? If you want futuretech, use ED (and ECD), which is much closer to what you're going for -- but still requires you to be able to reach the sensor you intend to fool.

But what does reaction have to do with it? I can see reaction in smaller scale tests, but I just don't see how it applies here.

I'm also unsure on the extended test bit. Generally extended tests deal with how long it takes to perform a certain task. Success is often just a matter of time and avoiding glitches. But success in this case is hardly guaranteed.

It is possible with noise (I'm not sure about radio waves) to sync up the waves with their precise opposite resulting in no noise. However, the amount of precision required is astonishing, so it really isn't feasible in any way if used on a flying platform against multiple targets and no advanced knowledge of what the pattern will look like exactly. So no, ECM doesn't do this. And no, a white noise generator doesn't work like this either. A white noise generator works pretty much exactly like ECM. Remember that a mic is vulnerable to a wider range of sound than our ears. So the white noise generator just fills the air with random air waves which cause such vibration on the mic that the audible stuff is overridden. It's exactly the same concept as ECM, it works by overriding it.

Reaction has a lot to do with this. Remember what I said about keeping close to the tree line? If you are within fifty feet of the tree line, your signature will be overridden by that of the terrain. If you're closer to 10 feet, you'll be practically invisible to radar. Of course, the treeline moves up and down (being full of trees), which means you'd better be a dang good pilot to be able to fly like that. This also has to do with precisely angling your aircraft so you present the smallest signature possible. The F-117 is more vulnerable to radar from the sides or rear than from the front, for instance.

Of course, the rule here is a gross simplification, and I'd throw it out. I'd require the pilot to determine how risky he's playing it. The closer he sticks to the tree line, the higher the TN (threshold, sorry) to avoid crashing, but the better cover he gets. Of course, an aircraft made for low speed, high maneuverability flying, sort of like the old Intruder jets in the Navy, or presumably a t-bird, will be easier to guide along like this than something fat and fast.

Your runners may also want to consider putting down, trekking over to the radar station, and putting it out of commission somehow until they can get the jet by. That is why you have deckers, after all.

It is apparently theoretically possible against radar (look up active radar cancellation), but it is indeed incredibly difficult and more likely to increase radar signature than decrease it under most circumstances.

Probably safer just to take your chances with the border patrol then mess with a military installation. The hacker can have loads of fun dealing with the drones.

A ship with a reasonable sensor suite should be able to detect stray radio waves before they're acquired as a target by the radar tower. A sensor test with thresholds based on how far out of range of the radar tower you are, modified by environmental factors may be appropriate. In my game, I generally run on the assumption that using radar makes it pretty obvious to everyone with the appropriate level of sensors that someone in the area is using radar. Lidar isn't quite so kind. However because radar is better for sweeping an area, it's safe to assume our radar tower will use it, and so our smuggler will likely know in advance there's a tower in the area (assuming he's trying to sniff out such things and isn't moving a kajillion miles an hour, and barring environmental factors. Sticking close to the tree line works both ways, so our smuggler could come over a ridge and be very surprised to see a radar tower sitting there waiting.)

Yes. That's what ECM is for, when the other guy already knows you're in the area and is just trying to get a lock on you (for indentification or engaging weapons).

As for actually visiting the tower in person... Hopefully they aren't stupid enough to go in shooting. There are plenty of other ways to temporarily jam a radar tower without the users ever being aware you're doing it.