Here is the first part of my house rules on Electronic Warfare.

The terms/words Jamming and ECM both mean the same thing; ECM to me is a more exact term.

I use or will use this optional rule from Arsenal in my house rules

As an optional rule, the Game Master can rule that jamming impedes sensors, and apply the ECM/Jammer rating as a negative dice pool modifier to all Sensor Tests and Sensor Targeting Tests.

To use a Radio Signal Scanner to detect and gain information on a active ECM signal.

Radio Signal Scanner (1-6) to detect a ECM signal is Electronic Warfare + Sniffer or Logic
1 success Detect a Jamming Signal General details, i.e. a ECM is active
2 successes Detect a Jamming Signal Major Details only, i.e. ECM is active, distance and bearing
3 successes Detect a Jamming Signal Major and Minor Details i.e. ECM is active, distance, bearing, make and model of ECM gear
4 successes Detect a Jamming Signal Completely detailed information altitude, and speed

Radio Signal Scanner is in the following distances, gains bonus successes to the test.

ECM signal source signal range equal to or less, +3 successes
ECM signal source signal range +1, +2 successes
ECM signal source signal range +2, +1 success

An active ECM signal is very easy to detect and then gain useful information about the ECM signal.

WMS

My first impression is that it makes ECM too easy to dected.

A short range SAM site (signal 6, 10km sensor range) is busy looking for smugglers to shoot down. The SAM site operator has an EW skill pool of 9 dice.

You are a smuggler with a rating 4 ECM (1 km footprint) trying to avoid being shot down.
The important range bands for this ECM are 4+1 (4 km) and 4+2 (10 km)

The smuggler crosses the detection range band of the SAM site (10km), so he turns on his jammer to give the SAM site some problems.

The SAM site tries to sort out his ECM signal, since they are within 10 km (ECM rating +2), they get +1 success. The SAM site rolls 9 dice, gets 3 +1 hits, and knows everything. Thus making your ECM useless.

If the smuggler had an more powerful ECM suite (rating 6), then the SAM site could get the same info on him at (ECM rating +2) 100km!

If the smuggler used a cheaper ECM suite (rating 2), then the SAM site could only get full info by listening at 1km.

That's anti-radiation homing for ya. Any really good evasion system 60+ years in the future would Spoof the missile's guidance or something. Just raising a huge ruckus on the radio isn't going to help at all.

(Really the jammer could transmit a copy of the radar's signal, like an echo, but out of phase so the radar gets a nearly constant feedback and zero information, but this will have been around for 100+ years in 2070, so let's just assume there's more to it than that).

Here's my quick attempt on this.

ECM reduces detection ranges by the signal range. (For example, a Rating 4 ECM suite would reduce your detection range by 1 km).
ECM suites may be easily tracked at (rating -2) range (altitude, heading speed) (So 100 m for a rating 4 jammer)
ECM suites may be detected as operating at (rating +2) range (So 10km for the rating 4 ECM)

So, to revisit our above example:

SAM, signal 6 (10km detection range)
Smuggler with ECM rating 4 (1km sensor reduction range)
The smuggler crosses the detection line of the SAM at 10km, turns on his ECM. The SAM site will burn through his ECM at 9km.

If the smuggler had a rating 6 ECM (10km sensor reduction range) instead:
Note that signals from this more powerful ECM can be detected by everyone and his brother at 100km, be careful with turning it on, it might make inquisitive airplanes fly your way.
The rating 6 ECM does completely blank out the SAM site.
But the SAM site can still fire on them at 1 km simply by listening to the signals the more powerful jammer gives off.

To what extent does ECM here refer to subtle and deceptive measures such as spoofing, deploying decoys, or tricks that were invented between 2008 and 20X6?

What about radar-absorbent paint and other measures to reduce one's radar profile?

Is "they don't notice us at all" one outcome to strive for, and "they know we're around but they can't get a targetting lock on us" another outcome to strive for? Are there tactics which give up on the former, to try for the latter?

Should we assume that the technologies and tactics of Sixth World are essentially based on current RL? (makes sense to me, just as we assume that 6th World revolvers work essentially the same with a few more ammo options)

See my previous entry on high-gain radio receivers:
forums.dumpshock.com/index.php?showtopic=19357&b=1&st=0&p=0&#entry0

You can do links directly in your posts like this, to that us lazy people don't have to copy and paste the link into a new tab.

this is done with the url tag
['url= (address goes here)'] (text that is linked goes here) ['/url']

(remove the quotes)

Please note that my post deals with a Radio Signal Scanner, and basically a Barrage ECM.

SAM's use sensors I would hope, and would have ECCM measures.

Yes in RL Barrage ECM's are that easy to detect and locate. As for Spot, Angle Deception, Range Gate Pull Off, Sweep, Base, DRFM, Active Cancellation and many others most here are not looking for that much details, as in like what Rigger 3 has, but even that was not complete. FYI the Spot Jammer listed in RAW is so wrong, it is funny.

Sensor ECM and ECCM will be posted when more complete. I posted the radio usage due to the fact the Sensors in SR4 are abstract.

If a smuggler gets with in a SAM sites Sensor envelope,, ie military grade sensors etc, I do not see a patch work system of ECM being used by a smuggler, being very effective against the SAMs sensors. I do not recall any borders with SAM sites in any published SR4/SR3 books. I see smugglers trying to get thru border security measures, a smart smuggler does not go where Military grade sensors are in place and used.

Basically ECM in RL does three things
1. Provides a Blinding wave of signal to blind enemy radars or radios
2. Changes target information like a Blip Enhancer changes the size of a ship ie destroyer is detected as a aircraft carrier.
3. Provides information that is not there like a ADM-20 Quail Missile, at the time it was developed, radars saw it as more than one B-52 inbound.
Link
Link

WMS

This point IRL is called Burn Thru.

WMS

I'd assume that most people want some ECM rules that more or less work and have some relation to RL, but don't want to deal stuff like exactly what kind of magic their ECM suite is doing to reduce the other guys ability to detect them.

If the sensor ranges (ratings of 0-9) were a bit more granular, then the rules could be more complex, but unless you want to completely rewrite the sensor/signal rules as well, the rules patch has to work in this collection of range bands.

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Using the sample rules you presented, a platform carrying an active rating 6 ECM can have a passive firing solution on it trivially done at 100km. It's also trivial to plot an intercept on the platform with the active ECM out to (we'll assume) 400km, since you can still get 3 hits on your EW pool alone. So what range band is it actually advantageous to turn your rating 6 ECM on? When you are further away that 400km from the people trying to detect you? But your theoretical jamming footprint is only 10km wide (actual signal 6 range)

A rating 4 ECM is 'safer', in that they can only get a trivial firing solution on you at 10km, and plot an intercept at 40km.

Of course, if the have something like a SA-5 site with an adept EW officer (who can generate 4 hits passive firing solutions based on his EW skill pool alone) and a bunch of spirits to movement the missiles, then turning on your ECM at all is basically asking for death, since the SA-5 never has to turn its radar on to kill you, and the missiles it fires all arrive horribly quickly.

The burn through example was:



The 1km firing solution was a passive solution based on listen to the ECM (firing in home-on-jam mode).

Detecting and targeting are two different tasks in SR4

For you SAM site example the SAM uses the sensor rules

SENSOR TESTS
To detect a person, critter, or vehicle with sensors, the character/vehicle must make a successful Sensor + Perception Test (Sensor + Pilot in the case of drones). If the target is trying to evade detection, make this an opposed Test versus the target’s Infiltration + Agility (metahumans, critters) or Infiltration (Vehicle) + Reaction +/– Handling in the case of vehicles. Since vehicle stealth is limited by the driver’s ability, the dice applied for Infiltration skill should not exceed the driver’s appropriate Vehicle skill. Sensors are designed to detect the “signature� (emissions, composition, sound, etc) of other vehicles, so modifiers from the Signature Table apply to the detecting vehicle’s dice pool.

SENSOR TARGETING
Characters can use the vehicle’s Sensor Attribute to help with Gunnery. They can do this by two means: passive targeting and active targeting.

Passive Targeting In passive targeting, the vehicle’s Sensor attribute substitutes for Agility (or Pilot) as the linked Attribute, so the attacker rolls Gunnery + Sensor. The target’s Signature modifiers are also applied as a dice pool modifier.

Active Targeting
Active targeting uses a vehicle’s Sensors to lock onto a target. To use active targeting, the character/vehicle must first make a Sensor Test to lock onto a target. This requires a Simple Action (see Use Sensors, p. 239). If the character/vehicle wins the test, the net hits are added as a dice pool modifier to the subsequent Gunnery Test. If no hits are achieved, the sensors fail to lock onto the target and an active targeting attack cannot be made.
Once a target has been locked onto, active targeting can be used against it without requiring additional Sensor Tests. If the target vehicle somehow breaks sensor contact, a new target lock must be acquired.

That is why I am keeping the two tasks separate.

No I do not want to rewrite the Sensor Ranges.

As of right now, in SR4 there are no rules that allow someone who uses a Radio Signal Scanner to fire/engage a detected target. You either "see" the target or you use the sensor test rules. Yes using a Radio Signal Scanner or a Commlink with the correct softwares you can attack a wireless node via the Matrix, but not physically attack it.

The ECM/ECCM sensor house rules are requiring more work, I do not wish to overwrite the existing rules merely add to them.

WMS

More devices

Device Grade ECCM Hardware (Rating 1-10)
Availability: (Device Rating X 4)
Cost: Rating X 1,100
Like a Pilot program each Device grade ECCM is purchased for a specific device like a Micro Transceiver or a Fairlight Caliban. Taking the device off a Micro Transceiver and putting it on a FairLight Caliban will not work. Each Device ECCM is basically built for each specific device.

Vehicle Grade ECCM Hardware (Rating 1-10)
Availability: 14F
Slot 1
Threshold: 20
Tools: Shop
Cost: Rating X 1,500
Special Skill: Hardware

WMS

From reading and comparing the rules for Electronic warfare in BBB and Arsenal, sensors ie vehicle mounted will require the ECM mod to affect vehicle or SAM site/missile sensors, the jammer listed in the BBB does not cut it.

WMS