Are you invisible with your Radar switched Off?

[Nerd1000]

but how could a radar on an aircraft flying east be detected on RWR on another flying west?

I know radar is a directed energy, not a hotspot, unlike radar on AD units that keeps swiveling 360 degrees and paints everything because of that.

 

Another thing I want to know, if an F-15 turns his radar on the ground and a ground crewman is standing in front of that radar, or a sandwich for example, does he or the sandwich get radiation sickness? or poisoning?

The radar energy isn't perfectly directed- while most of it goes where the radar is pointed, some escapes out to the sides and rear.

 

As for irradiating the hapless ground crew, take note that the energy emitted by a radar is not ionizing radiation. Generally an aircraft radar emits in the centimetric band, AFAIK usually between 1cm and 10cm wavelength. This is rather similar to the radiation emitted by a microwave oven, which doesn't give you cancer or radiation poisoning.

 

On the other hand, if you were to power up the radar and stand right in the middle of the beam for long enough you might get cooked like last night's leftovers. It could probably also interfere with or damage cardiac pacemakers, putting anyone with one at risk of going into cardiac fibrillation if they walked through the beam.

[Eihort]

Aircraft flying away from each other and RWR detections:

You don't. Not at 180 anyway. There's side lobes and other things that can make detections possible from angles outside the operating range, but they're kind of random at best and usually don't have enough power to trigger an RWR at meaningful ranges.

 

RF Hazards:

Yes. This is bad. Very bad. It won't kill someone with short exposure time but it's not healthy. In the case of the sandwich... well, what would a microwave do to it? Exact same principle. This is why a lot of aircraft have WOW (weight on wheels) safeties on radar and laser transmit functions. There are switches to override these so ground crews, in a controlled environment, can work on the systems, but in normal operation, they're kept off for a reason. In the case of Lasers, you could permanently blind someone, even though they're not in the visible spectrum.

 

NCTR:

Non-cooperative Target Recognition. One method for this is tickling the engine fans with radar and analyzing the results. Another is looking at the radar return itself. Each of these requires a certain processing time, and in the case of the engines, requires a specific aspect. A lot of how to do this is hush hush.

 

Passive RWR detections and EMCON:

So, as stated, an RWR is simply a spectrum and signal analyzer with a computer attached to it. Through various antennas located on the aircraft, it can determine direction of arrival of signals, and with some processing, tell you what system they're from, and what mode the radar is in. The MiG-21bis system is incredibly rudimentary compared to the A-10C and F-15C and tells you a lot less.

 

Now, repeat after me:

IN DCS RWRs WILL DETECT AN EMITTING RADAR LONG BEFORE THAT RADAR CAN DETECT THE AIRCRAFT. Use this knowledge to your advantage. This is why both the western RWRs and the SPO-15 have a method of determining the detected power level of emitters to try and inform you of whether or not you may or may not have been detected and/or the approximate range of the emitter.

 

EMCON or Emissions Control is a big deal on the modern battlefield. There are many systems such as VERA that are effectively ground-based RWRs on steroids. Flying around with your radar on in a modern IADS could leave you incredibly vulnerable to SAM ambushes and interceptors guided by GCI. The notion that pilots never fly with their radar off is false. If it were completely safe, they'd also fly around with jammers on too, and they don't, for the exact same reason. There are times where you do want them on all the time so it's not a pure blanket statement. How an air battle is going determines whether or not the risk of detection is worth it.

 

Keeping your radar and jammers off makes the enemy do all the work of detecting you, and that in and of itself can provide you with information as they'll have to turn on their radars to see you. With a decent RWR set, you can react to what they're doing and even avoid detection as you'll see their emissions long before they detect you on their radar.

 

Personally in multiplayer, when there's plenty of other allies flying around as a decent distraction, I keep the radar off and listen to teamspeak to get an idea where the bad guys are and sneak up on them as best I can. Contrails, missile launches, flares, afterburners all make other aircraft more visible at long ranges. If you know where they are but they don't seem to know where you are, you're at a huge advantage. I'll keep the radar off as much as possible, only transmitting to get positional updates as necessary to keep driving towards attack ranges.

[Yurgon]

Very good post, Eihort! :thumbup:

 

Now, repeat after me:

IN DCS RWRs WILL DETECT AN EMITTING RADAR LONG BEFORE THAT RADAR CAN DETECT THE AIRCRAFT.

 

Absolutely. But isn't this true for the real world as well? I think I read in the Falcon 4.0 manual that RWR detection range can easily be twice the radar's effective detection range. In other terms, if I can spot targets on my radar at 100 nm, the bad guys could detect my presence at up to 200 nm out.

[nomdeplume]

Absolutely. But isn't this true for the real world as well? I think I read in the Falcon 4.0 manual that RWR detection range can easily be twice the radar's effective detection range.

 

Makes sense. To detect a target at say 45 nm, the radar must emit enough energy for the radio waves to not just reach the target, but also be reflected back to the emitter. So it needs to be enough energy to travel at least 90 nm and still be recognisable, plus not all of the energy would be reflected to the emitter (some scattered, some absorbed).

 

I think it's also likely that you need a stronger signal for a radar system to be able to determine the precise distance a contact is away, in order to build a track and distinguish it from reflections from clouds etc. A RWR on the other hand only has to say "I'm getting a weak signal from this direction" and can be much more vague about the "distance", especially at long ranges. All it really needs to communicate to the pilot is "I'm picking up an emission from this type of radar, but it's too weak to currently be a threat".

[WildBillKelsoe]

so it is better to leave the radar turned off and get vectored by AWAC, then sneak up and turn the radar on at the last possible moment just before firing. I want to practice localising a radar location (EWR/SAM or EWR only) so the beam tells where that is. I think without a proper sized map or TAD it would be difficult.

 

So what happens really when a stealthy pilot who turned off his radar, lights, goes into a radar zone? Does he continue with knowledge of maximum range and what if that radar is supplemented by a momentary more powerful scanner to get accurate information on that pilots position, does he arc or turn back or extend range (beam the lighting blip)? keeping in mind he may not spot the more powerful, sneaky, radar or the two icons could be overlapping to tell which is active and which is not?

 

I know SEAD takes care of that with hunter-killer ® tactic, but what if that radar is dormant and never activates unless a phone call from a shoreline farmhouse to that brigade says "I see trails" or "I can hear a jet engine" or "I just got buzzed". How do they react and trace that sneaky bandit who by the way could be flying low?

 

Another question: do individual radars in real life project circular zones as in DCS or are they indiscernable areas (pizza slice shape, or blanket shape or other fuzzy shape) when looking down a territory in birds eye view?

 

So lets say an SA-3 is covering a 90 km x 90 km zone. what is the outline of this zone? I know it could be a square, or it could be a pie shaped if the emitters are pointing and fixed to an area, but what really is that zone looking like?

Edited April 12, 2016 by WildBillKelsoe

[nomdeplume]

So what happens really when a stealthy pilot who turned off his radar, lights, goes into a radar zone? Does he continue with knowledge of maximum range and what if that radar is supplemented by a momentary more powerful scanner to get accurate information on that pilots position, does he arc or turn back or extend range (beam the lighting blip)?

 

That's a bit like asking what really happens when a pilot engages in BVR combat. :) You can make generalisations, but the specific actions they take will depend on the particular circumstances. In general though, if things turn out to be not as expected, it's probably a good idea to get out of there while you still can and reassess your plans.

 

So in this scenario, was the pilot aware that the enemy possessed things with 'more powerful' radars? Was the pilot expecting to remain undetected at this point? If so, a sudden (but short-lived) spike might well inform the pilot that they aren't undetected, and therefore if their plan was to abort if they were detected early, then they'd abort.

 

On the other hand, maybe they weren't expecting to get all the way to a shooting position without being detected, but just wanted to reduce the amount of time the enemy had to react. In that case, they might well continue.

 

If the pilot is being supported by AWACS or similar, then they're probably providing better radar coverage than the pilot's own radar would provide, so they likely have pretty good situational awareness.

 

Another question: do individual radars in real life project circular zones as in DCS or are they indiscernable areas (pizza slice shape, or blanket shape or other fuzzy shape) when looking down a territory in birds eye view?

Search radars will generally perform a 360 degree scan, though I guess in some very specific circumstances they could be limited to a specific arc. Practically speaking though, you need to think in 3D: they scan a sphere (at least, the top half of a sphere). But it's common for parts of their search sphere to be masked by obstructions; terrain, trees, buildings, possibly weather.

 

So lets say an SA-3 is covering a 90 km x 90 km zone. what is the outline of this zone? I know it could be a square, or it could be a pie shaped if the emitters are pointing and fixed to an area, but what really is that zone looking like?

Depends on the altitude - a hill that's near the radar site could mask out a big slice of the airspace. But the air above it would still be in full view. Also, ground radar are just as susceptible to clutter problems as aerial platforms, so may have difficulty detecting/tracking contacts that are in line of sight, but have a mountain or similar behind them.

 

So generally speaking, higher altitudes will have better/more radar coverage than lower altitudes, and coverage will tend towards "circles centred on radar sites". Lower altitudes can get quite complex, though it's theoretically simple: anywhere that a radar within range has line of sight to will be covered. This is why most modern SAM systems are designed to be highly mobile. A fixed SAM site can be combined with a detailed topographic map to determine blind spots. If you don't know exactly where the site is, you can only estimate probabilities that certain areas aren't covered.

[Azrayen]

Another question: do individual radars in real life project circular zones as in DCS or are they indiscernable areas (pizza slice shape, or blanket shape or other fuzzy shape) when looking down a territory in birds eye view?

 

So lets say an SA-3 is covering a 90 km x 90 km zone. what is the outline of this zone? I know it could be a square, or it could be a pie shaped if the emitters are pointing and fixed to an area, but what really is that zone looking like?

See realistic profile here: https://www.lotatc.com/projects/lotatc/wiki/Detection_Profiles#The-REALISTIC-profile

 

This is LotAtc 4 DCS documentation. The realistic profile is this tool uses the same "rules" as DCS does.

The circles you see in DCS mission editor are just indications.

[FlightControl]

What about pulse and doppler radars? Your visibility will depend on your angle and direction vector with that radar?

[Azrayen]

If said radar is in look-down, yes.

[Eihort]

Absolutely. But isn't this true for the real world as well? I think I read in the Falcon 4.0 manual that RWR detection range can easily be twice the radar's effective detection range. In other terms, if I can spot targets on my radar at 100 nm, the bad guys could detect my presence at up to 200 nm out.

 

There are some radars that have LPI (Low probability of intercept) where they're difficult to pick out from all the other (un)natural RF noise, and can detect you before you realize you've been had. This is not modeled in DCS AFAIK.

 

Hypothetical SA-3:

First, 90km is way beyond the range of the system. Assuming reasonable numbers, it's as nomdeplume said. There's a lot going on there with WEZ (weapon engagement zone) and aircraft interacting. Nominally, all the earlier (single digits) systems require a search radar be attached to them so they know where to look because their detection zones are small beams. They have to know almost exactly where to point to see anything meaningful without attracting an ARM shot. The later systems are much more capable without EWRs attached, but then the later EWRs attached have FAR more range and are more capable (3D vs 2D without additional height finders).

 

IADS Sophistication:

Sometimes, all you really need to know is exactly where and when the target will be, and nothing else will be required, said no F-117 pilot shot down in the Balkans ever. The sophistication of an IADS can literally be that simple as someone just picking up a phone and calling another site to give them bearing and range information, or even a predesignated sector they "detect" an aircraft in with their "sensors". Insert whatever you want for detect and sensors.

 

I think it's also likely that you need a stronger signal for a radar system to be able to determine the precise distance a contact is away, in order to build a track and distinguish it from reflections from clouds etc. A RWR on the other hand only has to say "I'm getting a weak signal from this direction" and can be much more vague about the "distance", especially at long ranges. All it really needs to communicate to the pilot is "I'm picking up an emission from this type of radar, but it's too weak to currently be a threat".

 

Sort of. MTI (moving target indication) does an excellent job of removing false targets thanks to weather, ground clutter, etc. It's not perfect, but it get's the job done, even if it means that they're vulnerable to notch exploitation.

 

Range Determination with RWR:

Good luck. There are a ton of variables against you. Remember, in the western aircraft especially, the distance from the middle is roughly signal strength. It's really a function of "increased threat". It's different for each threat as an airborne system will have much less power at a given range than a ground based EWR system. The system accounts for this. A SA-10 will show "greater threat" at 50km while an SA-3 at the same range will show almost nothing. If the SA-10 is still at 50km and the SA-3 is now at 7km, they might show exactly the same threat level.

 

With the Russian system it's even harder, as you only have decent gradients on direction in your front hemisphere, and the best way to get bearing rate changes is to fly perpendicular. Also realize that the accuracy of an RWR can be off by several degrees and you need to be completely level for the antennas to pick up the signal and calculate everything correctly.

 

In short, the best you can get is "near, medium, far" out of it.