Radar

Before anyone can figure out how to interupt ECM between drones, they should probably learn how to effectively shoot down a stealth aircraft.

I didn't understand this ECM bit..
pardon me but the only ECM I know is the counter measures one..
Are we talking about that here?
And how will that interfere with comm. between drones?..
The way I see it, cell phone communication enables 100s of devices to comm with each other through a single central station..ANd on an average only 1 in every 150 calls/sms' is dropped. And the all work within a bandwidth of 50 MHz (control channel, voice channels and data channels all)

Also instead of storing all the processing power in one super comp.. why not distribute it amongst the drones themselves..programming them with decent enough levels of AI so that they can comm with each other w/o having to be routed through a central station..
A shortest path flooding algorithm of sorts..
And the mapping + fire control logic processors can be divided amonst the SAMs themselves..
Like co-processors comm with each other..

Say SAM 1 gets hits from drones 1,4,6,11
SAM 2 from drones 14,11,16
and SAM 3 from drones 11, 14

Each SAM independantly plots probable flight paths based on the data it has received and the sends this data to the other two SAMs via a physical line (reducing the wireless comm, and increasing comm speed/power)..
The common flight path(s) as predicted by all 3 SAMs is then inputed into the firing logic..

The key is distributing processing power..






Then the drones can directly comm. with the SAMs..

Again please explain this ECM bit to me

How did we get on ECM and drones? Isn't that in the "Jamming UAV's" thread?

[edit on 28-4-2005 by bios]

Originally posted by Daedalus3
The reason why LF radars are better suited to stealth detection are that LF waves dissapate much slower that HF waves..
In HF everything happens very fast, and hence is prone to quick loss of wave power..
And if LFs radar are boosted with more transmitting power, they're longevity increases in more..

As for intelgurl's note on LF interference due to similr freq. noise sources.. I am confused..

IMO most environmental/industrial/cosmic sources of noise are in the HF/VHF/UHF/EHF range..

Natalie~

THe only problems with LF radars that I can see are v high power requirements and large antennae sizes..
THe min. size and antenna can be to faithfully receive a particular frequency is 1/4th the size of the incoming wavelength...

Granted, I'm not an electrical engineer like you are, however the "low frequency" radar systems that represent a threat to LO & VLO aircraft are not necessarily in the "low frequency" range as you would see on a standard frequency spectrum (30kHz to 300kHz) but rather a comparative low frequency.

For instance the old Soviet era P-12 radar operates at 147-161 MHz (VHF) yet is considered a low freq radar, and according to various intel assessments could represent a significant threat to LO aircraft if proper processing were developed - this of course is a higher freq than what one would regard as "low frequency" if they are going by the book, but none the less it is considered low freq by the industry.

So in my reference to noise or more specifically electronic interference on a low frequency radar (not particle noise), I am actually meaning the frequency range that you pointed out as having the most "noise".

Sorry if I did not make that clear from the outset, I tend to leave out some details in my posts for times sake - otherwise I'd end up posting a thesis and bore everyone.

Natalie~

[edited to put the curl next to my name - gotta have the curl... ]



[edit on 28-4-2005 by intelgurl]

The ECM would make communications between the drones impossible, unless they had RJ-45 STP or fiber optics connecting them . Again, the idea is a great one on paper, but wouldn't work on a modern battlefield. And if you place processing in the SAM sites, as they get taken out by the stealth aircraft they're looking for you'll lose more and more inputs from the drones.

Umm.. wouldn't the drones in the air be shot down by stealth fighters before the stealth bombers go in and complete their mission? Then the SAM’s in the wont have any input from the Drones.

The drones are small.. and they being shot down itself is a direct indication of a breach..

Another question for the A2A missiles onboard a stealth aircraft.. are they radar enabled heat seeking stuff which acquire a lock before firing too?
Or are all missiles onboard stealth aircraft for ground strike only..
e.g: LGBs, GBUs, JDAMs etc..
I dont know if anyone's brought this up before if one has a PCL devices on the ground and say an F-22 tries to acquire an active lock then won't it give its position away?
Any radar guided missile or missile having its own guidance system will be like a 'torch beam in the darkness' for all passive listeners..

Again this "ECM".. what is this ECM.. can some please let me in on the term..
are you talking about noise?

As for taking out the SAMs themselves.. The strike aircraft will have to breach the drone patrol region to get to the SAMs right?
And say you do take a SAM out..or maybe a couple; that only reduces the processing power, it doesn't incapacitate it....
Moreover if the drones are programmed with decent enough AI, they should be able to alter course to get better returns..
Say a couple of drones get shot at or get faint readings in one region then they should be sentient enough to 'investigate' that..


As for cellphones, they don't need STP RJ-45 connectors..
They work just fine w/o any phy connection..
Relay all drone comm. through geosynch platforms maybe..I dunno..

Maybe a pictorial rep is required...
How does one upload paint bmps?

What I'm trying to say is that the drones,ground stations, PCLs, drone relay satellites and SAMS should be strategically placed so as to incur min loss before getting a decent firing solution..


intelgurl.. I ain't an engg. yet!.. Will graduate this June!!
But telecomm/wireless comm is one of my fav subjects!!

Note:In the ol' soviet being an engg. was considered to be good enough to get a prefix title like a med doc..
You'd have "Comrade Dr. Dostovsky"
and you'd have" Comrade Engg. Rozhdestvensky"

Fancy "Comrade Engg Daedalus3"...

And btw.. why the curl, intel-gurl?...



sorry ..Im a bit off the rocker today.. pardon the absurdities..







[edit on 29-4-2005 by Daedalus3]

I dont know if anyone's brought this up before if one has a PCL devices on the ground and say an F-22 tries to acquire an active lock then won't it give its position away?

that is a very good question?! Intergurl...???

Originally posted by 187onu

I dont know if anyone's brought this up before if one has a PCL devices on the ground and say an F-22 tries to acquire an active lock then won't it give its position away?

that is a very good question?! Intergurl...???

The scenario described does not have anything to do with a PCL system since the PCL system senses disruptions in the ambient noise of civilian sources such as cell phone, broadcast radio and broadcast television signals; it analyzes the data and determines through advanced processing that an aircraft is in the PCL's area of influence.

Therefore the pilot of an F-22 is not exposing himself to a PCL system by having his radar on, rather it is his mere presence and the manner in which his aircraft fluctuates these common broadcast signals that announces his presence to the operators of the PCL.

You may be interested to know that Lockheed's PCL system (Silent Sentry) was able to detect the space shuttle from over 370 miles away. That said, the specs for Lockheed's Silent Sentry lists it's detection range to be around 130 miles (220 km) with the following note: "Value based upon an RCS=10 m2 @ 100 MHz".

If you use the Fuhs formula with those values the PCL's sensory range would be about 43 miles (70km) against a 1 square meter target, and about 13 miles (22 km) against a 0.1 square meter target.

Therefore an LO (stealth) aircraft would have to be very close to the PCL system in order to sound off a warning. Also note that the ability to guide AA ordinance to said aircraft using the PCL is still not technically probable.

Natalie~

Formula taken from:
"Radar Cross Section Lectures," Prof. A. B. Fuhs


[edit on 29-4-2005 by intelgurl]

The ECM is jamming. Basically noise, transmitting garbage at the same freqs as the communications to drown them out. Think of it as a Denial of Service attack against a receiver. There is a whole thread about jamming in this topic.

As far as cellular technology, check out this article. It's about theater owners in New Zealand who want to start using cell phone jamming technology in movie theaters to prevent ringing cell phones from disturbing everyone else in the theater. This has ben in the news a lot lately, a lot of 'quiet' places like libraries, churches, etc., want to jam cell phones. Google it and you'll get a ton of hits.

I understand your system and I think it's great on paper. It just won't work on the modern battlefield with the amount of wireless communications you want to employ. That's why I recommended the shielded twisted pair ethernet cables.

Ah the jammers can work well IMO but there must be some specified ranges..
I do not know the basics of ECM so I cannot comment on their effect on my dear beloved drones..
How does ECM work.. Is it a spread pulse or a directed disruption..?
Will read up and then reply..

Originally posted by intelgurl
The scenario described does not have anything to do with a PCL system since the PCL system senses disruptions in the ambient noise of civilian sources such as cell phone, broadcast radio and broadcast television signals; it analyzes the data and determines through advanced processing that an aircraft is in the PCL's area of influence.

Therefore the pilot of an F-22 is not exposing himself to a PCL system by having his radar on, rather it is his mere presence and the manner in which his aircraft fluctuates these common broadcast signals that announces his presence to the operators of the PCL.


Natalie~

Formula taken from:
"Radar Cross Section Lectures," Prof. A. B. Fuhs


[edit on 29-4-2005 by intelgurl]

Ah.. interesting.. so the PCL doesn't listen for an active radar sweep from the target aircraft in question but listens to fluctuations in mundane braodcasts caused by the plane itself or its radar...

But wouldn't a listener or any omnidirectional receiver be able to detect an active radar pulse sent out by the F-22?
Or say the F-22 is trying to acquire a lock on noe or more of the drones..
Wouldn't its own doppler pulse sweep through the radio darkness like a torch beam?

[edit on 30-4-2005 by Daedalus3]

Yes, when the radar goes active, everyone knows it's there. That's why the 'stealth' aircraft prefer to hunt alone, without radio transmissions or radar emissions that would give away their position.

My ship, an Aegis DDG, was playing wargames with some German Tornadoes one time. We went to EMCON Delta, which means all electronic emmisions stop. We went into our 'stealth mode', using RAM coverings on anything topside that would increase our RCS, keeping our ship faced to the planes at the correct angle to minimize our RCS, and 'hiding' under a small storm cloud so we were always in the rain. We got visual on the Germans before they spotted us, but unfortunately we lit off our SPY-1D radar. It takes a few minutes for the tubes to warm up and the radar to stabilize. In that time we still couldn't track the Germans to fire at them but they picked up the SPY emmissions immediately, flew in, and waxed us. It was ugly.

Back to the pasive radars topic discussed before.
I was looking for info about todays most advanced passive radar system Vera (modernized Tamara) and it looks like the accuracy is similar to the low freq radar - tens of meters at 100km distance. Systems has 3 unmanned "listening" stations, microwave connection, and signal processor with 1 operator (at middle station). The max. range is 400km (220miles) and it can track 300 targets at the same time. The info is updated every 5 seconds. The antena weight is app 25kg.
link - pdf system info








[edit on 30-4-2005 by longbow]

Originally posted by Daedalus3
Ah.. interesting.. so the PCL doesn't listen for an active radar sweep from the target aircraft in question but listens to fluctuations in mundane braodcasts caused by the plane itself or its radar...

But wouldn't a listener or any omnidirectional receiver be able to detect an active radar pulse sent out by the F-22?
Or say the F-22 is trying to acquire a lock on noe or more of the drones..
Wouldn't its own doppler pulse sweep through the radio darkness like a torch beam?

[edit on 30-4-2005 by Daedalus3]

The vast majority of PCL's have a specific section of the spectrum that they listen to and target acquisition frequencies are generally not included in that bandwidth.
Case in point: Can you hear television broadcasts on your cell phone?

Having said that, there are certainly other sigint/elint systems that listen to that particular portion of the spectrum and could therefore endanger an F-22.

I'm sure that the F-22's AN/APG-77 could be detected but devices that typify what we would call a "PCL" are generally not listening for doppler pulses from a 77...

On the other hand, the AN/APG-77 transmits waveforms that change from burst to burst, and are sent at random frequencies. Such changing signals are supposed to appear as background noise and EW clutter to listening devices and are very difficult to detect and analyze - so just how easy the Raptor's 77 is to detect is another line of discussion I suppose.

Natalie~

Originally posted by longbow
Back to the pasive radars topic discussed before. I was looking for info about todays most advanced paive radar system Vera (modernized Tamara) and it looks like the accuracy is similar to the low freq radar - tens of meters at 100km distance.

Right, which is why currently these detection devices do not have the ability to specify precise locations for SAM targeting. With the Tamara you thought something was there, with the VERA you know something is there but you don't have a precise tracking. Give it a few years and it could become a considerable and significant threat...

Also, IS the VERA the most advanced? What does China have? How's the CellDar and Silent Sentry stack up against it? Silent Sentry can detect meteors the size of grains of sand ... Something to consider.

Natalie~

So for now niether system (VERA, Silent Sentra and Celldar) CANNOT "shoot" an LO aircraft down?!


Oh and Intergurl can you go back here and answere my last question?
www.abovetopsecret.com... (aircraft jamming 02)!!!





[edit on 30-4-2005 by 187onu]

Originally posted by 187onu
So for now niether system (VERA, Silent Sentra and Celldar) CANNOT "shoot" an LO aircraft down?!

To my knowledge none of these systems are actually feeding coordinates to SAMs. They can give a general location and then use a tactic of saturating the airspace with SAMs as is the suspected method used to bring down the F-117 over Kosovo.

Natalie~

saturating the airspace with SAMS would still have a very low probability of success...

That F117 would have been a very hard target it hit if they were just flinging missiles up there without a lock

That F117 would have been a very hard target it hit if they were just flinging missiles up there without a lock

Not unless you know the flight path of the F-117, which is what the Serbs knew. Then you can still fire without a lock, because when you combine general location with the flight path you increase your chances at shooting it down.