Talk:Kolchuga passive sensor

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[edit] Edit on 3 Oct 06

The edit on 3 Oct changed "Kolchuga is able to detect and identify most active radio devices mounted on ground, airborne, or marine objects." to "Kolchuga is able to detect and identify 500 specimens for 300 types of radio devices mounted on ground, airborne, or marine objects." I have reverted this as the English doesn't make any sense. It's not clear what a "specimen" is in this context, nor what the 300 types is referring to. A reference should also be included - where have these numbers come from? They are suspiciously round figures! I recommend that the author explains in more detail what he meant by this edit here (in the Talk page), with a reference if possible, and then I will help put it into better English. Thanks!

--Paul 05:53, 4 October 2006 (UTC)

[edit] RTD specimen identification

Hi Paul,

OK, I am sure that my English often is unreadable, so I will use a lot of words to be more explicit :).

I see you have a various contribution to the projects related to the ESM station. So, as you know, one of the important parameters of ESM is the time of the automatic identification of RTD (Radio Technical Devices) according to the Standard Description of the sources of radiated electromagnetic energy and the quantitative capabilities of that identification.

The number of signal parameters used for automatic identification depends on the implementeddetection algorithm. Detection and identification are diverse procedures. The Kolchuga (before 1996) uses 40 signal parameters for automatic identification, Ramona(Tamara)- 4 parameters.

The high numbers of used parameters give the ESM the possibility to do the identification in two stages: first identification of RTD type and second the identification of RTD specimens inside that type. That means, at least theoretically, that ESM can identify the individual characteristics of the RTD implicitly maybe the individual aircraft or land unit. It can be said that specimens are the "fingerprints" of the RTD :) That is the way the constructors have been defined the terms RTD Type and RTD Specimens.

Around 1997 it’s been believed that the Avax AN/AYR-1 has capabilities to keep up to 500 (round figures :) classified RTD type in their automatic database of Standard Description of the Source Type (SDST). Ramona(Tamara)has up to 100 SDTS capabilities directory. Kolchuga has up to 100 of SDST with automatic identification of up to 500 specimens inside each type. Ramona(Tamara) doesn't have the automatic "fingerprints" (specimens) identification capabilities. Around 2000, the Kolchuga tripled their automatic database directory.

EMS detects anything that they receive, but can identify only the RTD that they already have in the Standard Description of the Source Type Database (SDSTDB) and in number not more than the constructive limits. In that order the sentence: "Kolchuga is able to detect and identify many types of radio devices" is inexact. Kolchuga (as any ESM) is able to detect any radiated electromagnetic energy at the site in respect of their sensitivity and frequency band, but can identify not more than 300 types of radio devices, and can automatically identify not more of 500 specimens of the devices for each defined type. That is done evidently with some probability factor. If some signal was detected and identification failed they will be shown and recorded as unidentified type or specimens.

"Suspiciously round figures" obviously come from the initial design specification provide by army, which operate with the targets number not the bits number, and become the constructive element of the ESM as a part of hardware implementation of Automatic Identification Algorithm. (Old stations, about we talk, is more "hard" than "soft")

Maybe some data is not so real, as often happens in this mater :) but at least they have been released by officials with different occasions. Generally speaking, from the point of view of data flow structure the Kolchuga has more similarities with Avax systems than with Ramona(Tamara). Ramona(Tamara) is a very good implementation. It seems that the difference between these stations appear due to the different intended purpose of the stations at the design stage, and not due to the technological capabilities of the constructors (except the nanoresonators, that permit Kolchuga to achieve -145dB sensitivity and better).

By the words.., I don't understand what means in English from technical POV: "antennas, which provide for high radio sensitivity within a 110dBW - 155 dBW swath". Kolchuga's antennas gain, I think, is "only" about ~35dB. What you think?

I don't think that all that technical mater is suitable for the article that must remain the general purpose encyclopedic review and not technical topic. If you want to help put few ideas into a better English and very short form suitable for the article, you are welcome to do that.

Thanks!

--feelfree feel 13:15, 6 October 2006 (UTC)

[edit] Response

Hi Feelfree. Wow - thanks for the very detailed response. That's clear now. I've tried to summarise the essence of what you said in an additional paragraph in the main entry. Feel free to correct if you think I've misrepresented what you meant. As regards the "110dW - 155dBW" swath, I'm not at all clear what the author of that statement meant. I guess they were referring to the range of sensitivities the system has with its different antennas, and probably meant -110dBm to -155dBm. However, without further information I'm not confident to edit this.

--Paul 14:55, 6 October 2006 (UTC)

[edit] Edit 6 Oct, regarding plasma fields

This edit added "As against stealth aircraft, it has been speculated it coult detect the radiofrequency emissions of the plasma jet exhaust, or it could be used in conjunction with short burts of auxiliary active radars." I removed this pending discussion as it seems physically impossible. Specficially, I'm not aware that a plasma from a jet's exhaust emits any RF energy - plasma reflects and absorbs RF energy, but not radiate AFAIK. If this effect exists, what is the ERP of the emission and at what range could it be detected? I suspect it's unfeasible and hence not something for an encyclopedia entry. As for auxiliary active radars, this is highly unlikely. Firstly the stealth characteristics of the aircraft would apply equally to the auxiliary radar and, secondly, Kolchuga would not have a matched filter to the auxiliary radars and so would be at a significant disadvantage for detecting any reflection - even for a conventional aircraft, let alone stealth. Forward scatter is the only possible exception to this. If either of these claims is to be in the entry, some calculation or reference seems essential. --Paul 21:07, 6 October 2006 (UTC)

The info about 1)charged particles being in the exhaust and thus EM radiation emitters and 2) using auxiliary active radars for the super-sensitive Kolchuga ears to triangulate came from discussion at [1]. I believe I used the word speculate. Why so quick to delete Paul. Best Wishes. Will314159 23:35, 6 October 2006 (UTC)
Thanks for the comments. Speed of deletion was nothing personal - I just happened to be checking the pages around the time you posted. Reasons for deleting I gave above. The content you added is really not technically feasible, for the reasons I gave. Plasma does not radiate and if you do the energy calculations you'll see that using Kolchuga as an opportunistic bistatic radar receiver would also be very unreliable, save for a few lucky hits in forward scatter. Even then, efficacy against a stealth aircraft is unlikely. The forum you found this information on is very enthusiastic, but technically wildly off the mark most of the time. I work in passive sensor technologies for my day job (although admittedly not on Kolchuga) so I do have experience in this area. However, given that Kolchuga is a continual source of enthusiastic speculation, I'll modify the entry to add a section for "Rumours and speculation" which these kind of claims can be recorded. However, as an encyclopedia entry and following Wikipedia\s neutral point of view, I think we must be very careful about mixing neutral technical fact with enthusiastic speculation. Nothing personal! ---Paul 05:42, 7 October 2006 (UTC)

VERY nice work. I guess for stealth it's back to optical tracking and using cell phones. I wonder if there's a WP article on Stealth aircrat detection? Best Wishes Will314159 12:53, 7 October 2006 (UTC)

[edit] Horizon distance formula

Hi Paul! You are sure the formula: d=130(\sqrt{hr(km)}+\sqrt{ht(km)}) that you indicated in Kolchuga article is correct for any type of transmitter receiver pair. Can you give some reference for it? Thanks. -- Feel 22:25, 12 October 2006 (UTC)

Hi. This is just based on simple geometry - but I've given a reference now. Imagine an object at height h above a sphere, then the distance to the horizon is d=sqrt(2kah) where a is the radius of the earth and k is a factor to allow for diffraction (typically 4/3). The line of sight between sensor and target is limited by the horizon, so you can calculate the maximum line-of-sight range by adding the the distance to horizon of the sensor to the distance to horizon of the target. It turns out that if distance and height are in km then the factor sqrt(ka) for k=4/3 is approximately 130. Hence the formula I gave. It is explained on p.449 of (Skolnik 1981) but it's trivial to derive by hand. In reality, performance would be worse due to terrain screening, which this simple formula ignores.
--Paul 07:08, 13 October 2006 (UTC)
Reg. Cleanup
Hi Paul! Thanks for explanation but they are questionable. If I will use mentioned formula for ground level operation (3m emitter and 3 m receiver elevation) line of site will be only about 14km. That means that any ground level communication over14 km is impossible. That is non sense. Probably this mater must be discussed in the “line of site” article.
Additionally many details in article look none encyclopedically. For example: “can detect only very powerful emitter”. In that case “very powerful” is more powerful or less powerful than emitters that can be detected by the station that has 100dB sensitivity? Or the electromagnetic reflection of the small bird is the "powerful emitter" as they can be detected? Detection capabilities are defined in industry by the sensitivity. If the Kolchuga have 145 dB sensitivity they can detect in the same condition an emitter with 45 dB less power than the some station with 100 dB sensitivity. Article has a lot of such details and I don’t understand way the Kolchiga article look like election manifest instead of technical review. Can I help you in same way in that question? Thanks, Feel 03:21, 5 November 2006 (UTC)
Actually, it's not nonsense. It all depends on the frequency. If you are thinking of a microwave link, then 14km is all you'd get. That's why microwave point-to-point links require tall masts on hills to get decent ranges. Companies wouldn't waste money on that unnecessarily! However, at lower frequencies (VHF and below) then there is signficant diffraction and this will extend the range beyond this simple formula, which is why your FM radio works at ground level (although note that most FM radio transmitters are on 150m towers!). However, for the majority of Koluchuga's frequency range, these effects will not apply. The formula is therefore a pretty good approximation. It is also standard for calculations of this type, so I'd be very cautious about believing it is inaccurate beause it doesn't support the hype on Kolchuga.
I agree the technical parameters are poor. This is due to lack on any accurate information. However, given that people insist on stating the range is up to 800km, then it is necessary to caveat this with the warning that this will only be for powerful emitters. Exactly what "powerful" means needs detailed sensor parameters to quantify, but as a general statement it is accurate. I sincerely doubt that Kolchuga could ever detect the reflection of a bird - whoever is stating that is being rather liberal with the truth. Do the math!
Unless we get some better sourced parameters (eg. a manufacturer's brochure), I'm not sure the article can be improved much further and will inevitably be rather generic in language.
Cheers. --Paul 08:54, 5 November 2006 (UTC)

[edit] reg.: brochures

Hi Paul! Ok, I have the sense of humor and hope you have it too and I understand that ground to ground EM wave detection is impossible over the 14 km distance for ANY type of emitter receiver pair and will not try to do that at home. I also understand that ELINT station (that Kolchuga is according the official classification) are like my FM radio and the aircraft is so expensive because they a like the masts on hills. But come back to enciclopedical content of the article.

1. I never suggest that Kolchuga detect the reflection of a bird. I mention the bird in context that if typical radar can detect reflection of the bird, that means the signals of similar power can be detected also. Paul, not the emitter’s power are in the question, achieving the good detection capacity are the problem. If constructor knows what they must detect and in which way they can detect that, they can elaborate the detection algorithm. It’s easy: “Put the problem – solve the problem”.

2. Regarding the "Skolnik" line in site formula(by the way, in russian "Skolnik" means pupil) . Of course it is look like good formula. But you probably know that Atmospheric Radio Wave Diffraction that you mentioned is only one of multiple phenomena that happen in real Earth condition. Skolnik manual Introduction to Radar Systems (1981) is only introduction and introduction to radar systems. Kolchuga isn't radar they is ELINT station. Radars use primary emission detection (in radar case this is reflection) suitable for precise coordinate calculation. Secondary emission doesn't help yet in precise coordinate definition (the main purpose of radar). This formula treat only capacity to detect primary emission That formula isn't relevant for secondary emissions of normal propagation as is Scattering, Ionosphere Diffraction etc. and cant be used for another type of propagation as is Half Space Wave, Ground Wave, etc. All that phenomena have their own lain on site. ELINT can be built to use any of those emissions that help know something about target, but ELINT yet isn't capable to calculate the coordinates to shoot the target, for that we need radar that have line in site formula mentioned by you. That was the reason I have asked you about ANY TIPE of emitter-receiver pairs.

If the radios companies will succeed in one day make each of us to buy an ELINT station you may be sure that after that the company will use very cheap transmitters to cover aria and will not spend many for the towers on hills.

3.All that I write hire above is a speculation, because I remember the discussion of two general constructors of two concurrent artillery fire radar systems that took place long time ago. One was from NATO and one from Soviet. It was amazing how match information they exchange in the discussion: “I do that … In which way you solve that problem?” “O yes, I meet that problem, I do that and that to solve it …” But in one moment one of them asks: “What link you use in your phase detection matrix, horizontal or vertical?” Theoretically that is the trivial question, but the answer was: “O! Sorry, that information I can’t tell you.” At that time I learn that the big achievement is hidden in the concrete engineering implementation rather that in the general principles.

4. I have the manufacturer “brochures” for all three models of Kolchuga issued by Topaz. I have also the US and UK State inspection report regarding the Kolchga as well the UN weapons inspection report on the same mater but I don’t now were is the sense to transform wikipedia in the technical data sheet. What is your idea about how to proceed? Feel 01:26, 9 November 2006 (UTC) Feel 03:24, 9 November 2006 (UTC)

Hi Feel. The reason a radar can (sometimes) see a bird is because it has the advantage of being able to use a matched filter in its receiver. This can add 10's of dB's of processing gain. An ELINT or ESM system like Kolchuga can never have a matched filter, as it would have to be matched to 100's of types of waveform. Kolchuga can therefore never achieve anything like the sensitivity of a radar. I agree with you that, if we relax the requirement for Kolchuga to perform accurate *location* of a target, then you could consider some of the propagation mechanisms you mention, for some frequencies. However, I still think for approximating the basic tracking range, the formula is as good as we can get. Why not create a section called parameters, and list the key parameters given in the brochures there, as a list? It's more than the article has now. Mention the source too. Cheers. --Paul 19:05, 10 November 2006 (UTC)

[edit] The updated passive station for radio electronic control (Kolchuga M?)

The updated passive station for radio electronic control (Kolchuga M)

Are equipped

With four aerial antenna of VHF, UHF and SHF band of waves with narrow beam and wide beam, With the parallel receiver allowing to discover instantly and to analyze signals of RTE in range 100MHz -18,0GHz and to continual tracking into entire band along the field with sensitivity of approximately -145 dB/W With the equipment of analysis, processing and continual calculation and tracking of coordinates by triangulation and chronometrical-hyperbolic method. With equipment of identification, operative displaying of information, long term memory and booking of the results of processing.

Provide

The revelation, the analysis of signals with impulse and continual beaming and individual distinction of practically all known Radio Technical Equipment (RTE) settled up on ground, sea and air carrier that include radar units of all classes, identification systems, air traffic control system, navigation system Provide the composition, the character of operation and the routes of transfer of RTE in the zone of 600 km deep with complete exception of dead zones with continual high accuracy in any point of controlling space. Provide the detection of the fact of take-off of the aerial targets and formation their in the groups on the distance exceeding distance of the modern radars. The definition of the direction of the transfer of solitary and group targets and target indication to active facilities of AAS

Surce: Topaz brochure issued 1997 at AIDEX Feel 22:53, 10 November 2006 (UTC)Feel 22:54, 10 November 2006 (UTC)

Good information - I've updated the article to include this. I took the liberty of correcting the English to make it read better, but didn't change the meaning. --Paul 14:13, 11 November 2006 (UTC)

[edit] Rumours and speculation of performance

test Question Mar07 In the section History it says that the system actually cancels out the billions spent on stealth technology. But when reading the enitre article the article says that this is either unclaimed or that stealth planes dont go into battle with RF emitting. That sentence doesnt belong there and must be changed because it is contradicting what the whole article says.

[edit] Stealth RF modulation

It is not true that F-22 operate without being picked up by Kolhcuga as the datalink emits detectable UHF signal.