MiG-31 Avionics

overscan (PaulMM)

overscan (PaulMM)

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Thread to discuss MiG-31 Avionics.

Here's a pic showing the multicolour HUD... from Koku-Fan, October 1992.
 

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I would like to know the status of Mig-31 in RuAF fleet few questions regarding it are

1 ) How many Mig-31 in various variant exist in RuAF fleet

2 ) What kind of Modernisation did the Mig-31 go through , There were the M and BM program to give it a multi-role capability.

3 ) Is there any plan to replace the Zaslon-M with some other AESA variant or any other , The Zaslon-M in this age is not exactly state-of-the art
 
8TP/8TK IRST

Developed by a team lead by D M Khorol at Geofizika, starting in 1970.

The 8TP is installed in a retractable cylindrical housing, and uses liquid nitrogen cooling. Testing started in 1977, and was declared operational with the MiG-31 in 1981.

Scan angles of the 8TP are +-60 degrees in azimuth, +6/-13 degrees in elevation. Angular resolution is 15 minutes. Power consumption of the unit is 1.3kW, MTBF 350h, weight 124kg.

Range is about 40km against a rear aspect fighter target in military power, 100-120km against an SR-71 in full afterburner.
 
According to Valery Romanenko, who researched for Paul F Crickmore and interviewed ex MiG-31 pilot Mikhail Myagkiy, when flying anti SR-71 missions the IRST was the primary sensor. The radar would be set to combat frequencies but switched off, and the intercept would be flown using the IRST. The onboard computer could calculate range based on triangulation with "other onboard sensors".
 
The Zaslon is often compared to the AWG-9 in terms of range and features.
Bar the phased array, the published figures seem to indicate that the AWG-9 was in fact superior, both in terms of range, modes, and Situational awareness ( 24 targets in TWS!)

I'll post a few excerpts about the former.
 
PHASED- ARRAY RADARS: FACTS AND ILLUSIONS

AirFleet, 2002

Yuri Bely, Director, NIIP
Vladimir Zagorodny, Chief Designer, chief of a division, NIIP


It was an open secret that for the past quarter of the century the United
States has been working on active phased arrays to equip airborne radars to
be fitted to new-generation aircraft.
Various sources have been providing information on the status quo in this
field regularly enough, mentioning principle scientific and technical snags
hit in developing the primary element of the active phased array - the
transmit/receive module. In the long run, the module was supposed to feature
three main things to be given the nod, namely high electric characteristics,
minimal weight and dimensions and an affordable cost. Also reported were
high development costs and continuous lagging behind the schedule.
Nonetheless, having set many years ago the strategic goal, i.e. developing
an active phased-array radar for their future aircraft, the Americans have
stuck to it.
Some time later, European countries - France, Germany, the UK (the ones that
set up an APAR consortium) and Sweden - joined the race.
Mention should be made that all those concerned knew of the above programmes
full well but no one has expressed any concern until recently.
25 years of hard work of US scientists, designers and production engineers
could not but produce a result. Last year, the emergence of the first active
phased-array radar prototypes for the F-22 and F-35 fifth-generation
aircraft and their flight trials on flying testbeds were reported. The
reports shocked part of the Russian military industrial complex. Just two
years before, 'live' active phased-array radars were the matter of the hazy
future, and here you are - real active phased-array radars - rather than
mock-ups - equip warplanes and 'see' their targets.
A good reason for losing heart though! Today, the motto 'Go APAR!' is all
the rage. However, today, developing a Russian active phased-array radar is
no small beer at all.

It is high time to recall here the thirty-plus-year experience of the NIIP
Research Institute of Instrumentation named after V.V. Tikhomirov in
developing airborne passive phased-array radars (PPAR).
In 1968, the Tikhomirov-NIIP was tasked with developing the Zaslon fire
control system to equip the MiG-31 heavy interceptor. That unique system was
world-first to feature a passive phased array with the multiple-target
track-while-scan capability and the capability to guide long-range missiles
to four targets simultaneously.

In 1981, the Zaslon fire control system-equipped MiG-31 was fielded with the
interceptor fleet of the Air Defence Force. Even today - over 20 years
since - we cannot but recognise the novelty and courage of the technical
solution embodied in it both in terms of hardware and software.

Further upgrade of the system ensured a hefty increase in the lock-on and
engagement ranges totalling over 300 km and upwards of 240 km respectively.
The radar proved capable of tracking 24 targets at a time. "This is our
mini-AWACS," its developers would joke proudly. They were quite entitled to
be proud.

???

Naturally, NIIP chief designers wanted to use the passive phased-array radar
in developing future radars for lighter fighters like the Su-27. Alas, the
customer did not share their enthusiasm. The passive PAR's principal
drawbacks were believed to be its rather heavy weight and high cost.
Actually, as early as then those drawbacks decisive. A certain excessive
weight of the radar never scared the Designer General of the Sukhoi design
bureau. "We need a capable, 'smart' and dependable radar. As to the
excessive weight, we can handle this," Mikhail Simonov used to say. With the
passive phased-array radar in full-scale production, its cost was expected
to be affordable, which was later proved by the Zaslon's series production.
While developing airborne radars in the late '70s and early '80s, US and
European designers widely used planar slot arrays driven by three-stage
electric or electro-hydraulic actuators. The bad habit of copycatting the
Americans resulted in slot arrays for the Su-27's and MiG-29's radars
becoming all the rage. As a result, for over 20 years since the Zaslon
fielding (1981), no single aircraft fielded with the Russian Air Force has
carried an airborne electronic scanning radar.

It was only in the early '90s that many realised that 'single-purpose'
mechanically-scanned radars were a deadline with no future, since attacking
several targets in the track-while-scan mode is mostly publicity, a
promotional trick, rather than a reality, and could not be employed in
action in most of the cases.

At the same time, the Tikhomirov-NIIP started designing a drastically novel
passive phased-array radar featuring the so-called 'command-type' control
system ensuring a weight reduction and an electric characteristics
improvement. Despite the institute's dire financial standing, it still
manufactured and adjusted two prototypes of that passive PAR, with one of
them being installed in the Su-35 flying testbed (side number 712) as part
of the Bars radar. During the tests, the Bars' earlier variant, fitted with
a five-kilowatt transmitter, proved to be capable of acquiring Su-27
fighters at a range of over 330 km, tracking several targets while scanning
the airspace, identifying aerial targets, etc. Those achievements were
embodied in the latest version of the Bars airborne radar.

Mention should be made that latest passive PAR improvements have been
embodied in a most comprehensive manner in the Skat-M passive phased array
designed for the Osa radar. The array's flight tests are slated for the
later half of 2002. Thus, today Tikhomirov-NIIP is the only Russian defence
contractor capable of developing, manufacturing and operating electronic
scan radars.

The Ryazan Instrument Plant (Russian acronym - GRPZ) have mastered the
passive phased array production techniques in full. On the face of it, there
have appeared a feasible opportunity to quickly derive a radar for the
fifth-generation aircraft at first from the passive phased array mounted,
for instance, on a two-stage electro-hydraulic actuator. However, recently,
this variant have begun taking aggressive and unsubstantiated flak in
periodicals, dedicated publications and conferences on the part of certain
radar developers. What is most striking is the criticism is dished out by
specialists with no practical experience whatsoever in developing and
testing airborne passive phased-array radars. Their statements that an
active phased-array radar might have been built by as early as late 2002 are
bewildering, to say the least. Unbiased and comprehensive comparative
analysis of the passive and active phased arrays have never been made due to
complete lack of the technical characteristics of such an active phased
array. According to Tikhomirov-NIIP experts developing passive and active
phased arrays, today building an APAR with the use of the existing
componentry will result in such an APAR being too heavy, too expensive and
mediocre in terms of electric parameters.

With Tikhomirov-NIIP's work on active phased arrays being underway, the
company's strategic policy on the matter is very simple and easy to grasp.
It boils down to developing the so-called 'parity' active phased array
rivalling the best passive phased arrays by 2008-2010 through pooling Russia
's whole scientific and technological resources which could be useful in
resolving such a challenging problem.
At the same time, since active phased-array radars are expensive enough,
cash-strapped countries might be offered a passive phased-array radar
providing all advantages of electronic scanning at a far lower cost.
It is worth mentioning here that US and West European designers have yet to
resolve all problems inherent in active phased arrays, with the list of
remaining snags being large enough and deserving a separate article.
Development of a Russian active phased array radar is too complex a problem
for it to be resolved by a 'cavalry charge' - via unsubstantiated statements
and allegations. Different branches of science and industry have to pool
their efforts, with financial, technical and technological resources having
to be pooled as well. Tikhomirov-NIIP realise this full well and are ready
to accomplish the task they face.


---------------------------------------------------

Any ideas of which radar they are referring to when they mention those ranges and track 24?

Is it the Zaslon AM?
 
Airfleet #9, 1999

MIG-31 ZASLON
By A.I. Fedotchenko


The late sixties:
The Cuban missile crisis is already history, however, the Vietnam war keeps
raging on - a major war characterised by the wide use of aviation. The
memories are still fresh of downing the American U-2 Blackbird
reconnaissance plane travelling at Mach 3 over the Urals mountains - the
heartland of Russia. The Soviet Union had to find an adequate answer to the
threat posed by the US and NATO and, first of all, cover its northern border
from air attacks including cruise missile strikes. The situation caused the
development of a most efficient interceptor.
The thousand-odd kilometre border could not be effectively defended by the
then air defences and MiG-21 fighters. A new interceptor had to have long
legs to push the intercept range off as far as possible. It also had to
develop maximal airspeed and be able to win in aerial combat both against
single and multiple 'bandits'.
Even this brief outline of the situation in the second half of the sixties
indicates the Soviet Union had to design a radically new interceptor
aircraft.
Such an aircraft was designed and fielded in 1981 with the Aviation of the
Air Defence Forces.
The development of the S-155M interceptor aircraft was assigned to the
Mikoyan Aircraft Design Bureau, while the Tikhomirov Instrument-making
Research Institute (then known as Radio Industry Design Bureau) was tasked
with designing its guided weaponry.
In 1968, the programme was given green light by the resolution of the
Council of Ministers and Communist Party's Central Committee of 24 May, 1968
(?397-152).

While Mikoyan had built the MiG-25 with its performances closely matching
those of the prospect interceptor, the Tikhomirov NIIP had no such an edge.
And the task was formidable -the NIIP had to develop its first long-range
radar capable of detecting enemy aircraft against the ground with the
targets flying on the head-on or pursuit courses. None of the then radars
was that capable. To cap it all, the radar had to be able to track the
targets acquired (i.e. to update their coordinates and position regularly)
within the maximal wide coverage area.

The NIIP christened the weapons control suite as Zaslon - Russian for the
'barrier', 'obstacle' - the barrier at the Russian border.

Nearly all technological solutions were innovations. For the very first
time, there was the high-repetition pulse radiation (so-called
quasi-continuous radiation) employed, as was digital signal processing,
integral computer. For the first time, the navigator was provided with both
detection indicator and tactical situation display. For the first time, the
discrete target illumination and missile semiactive guidance through the use
of discrete signals were developed as was the multiple target tracking and
engagement capability. For the first time: well, one could carry on and on
with it but let us dwell on the most important things.

The Zaslon radar pioneered the phased array. To date, there have been no
interceptor across the globe that could boast a phased array. Almost all
combat capability of the new interceptor emerged due to the phased array
radar (PAR).

The radars of the time operated a mechanical drive to scan the aerospace.
When the antenna's ray hit a target, the drive would begin tracking the
target, while the pilot would be completely unable to keep abreast of the
situation and see any other targets.

The track-while-scan technique is only a partial solution to the problem,
since it can provide neither wide coverage areas, nor high precision of the
target coordinates.

The emergence of the PAR solves the problem radically. Reorienting the ray
in any direction within the cone of 120œ - 140œ takes the radar mere 0.001
sec.
The peak of the whole MiG-31/Zaslon FCS programme was the flight test of 15
February, 1978. On that day, the MiG-31 took off to detect, lock on and
track 10 targets simultaneously.

The targets travelled towards the interceptor in two groups at both higher
and lower altitudes than that of the MiG-31. The targets were detected and
locked on at a range of 140-180 km. Tracking was stable. The experiment was
crucial for the interceptor's designers. It became obvious that their work
had come to the fruition. Even though nearly two years of further tests
loomed ahead, they were sure they would succeed. The second landmark
experiment was the interceptor's simultaneous destruction of four led
targets.

As a result, the following MiG-31 characteristics were confirmed:
- programmed aerospace coverage; detection, lock-on and simultaneous
tracking of up to 10 targets within the 50-2,800 m altitude brackets in both
good and adverse weather conditions with the enemy electronic
countermeasures (ECM) (scan area of -/+ 60deg-70 deg;

- detection range for the SR-71 and F-16-like targets against the ground
makes up 200 km and 120 km respectively;

- 4-target simultaneous engagement with guided missiles in parallel with
calculation of launch parameters;

- control of the interceptor while cueing it in on the targets, discrete
target illumination;

- cannon fire;
- passive infrared (IR) target search capability;

- semiautonomous operations of 2-4 MiG-31 teams - a 4-aircraft team could
swap data on the 800-km frontage at a distance of up to 2,000 km from the
ground command post;

- cueing MiG-23s, MiG-25s, MiG-29s and Su-27s in on targets.

Twenty years later. July 1998. Four Su-30s and two MiG-31s took off the
Savasleika AFB (Nizhny Novgorod region) to be joined later by an A-50
airborne early warning and control aircraft and two Il-78 tanker planes. The
formation passed along the following route: Savasleika - Astrakhan - Moscow
region - Novaya Zemlya archipelago - Savasleika. The crews were not ferrying
their aircraft back and forth, rather, they maintained communications among
themselves and with the A-50 airborne command post, as well as accomplished
a variety of missions en route.

They would assume various group formations - a MiG-31 would lead the Su-30
strike aircraft and enable them attack ground targets, then the Sukhois
would protect the MiG-31s from surface-to-air missiles to enable the
interceptors to stalk a faraway aerial target and shoot it out of the sky.

The MiG-31 Zaslon is still in the inventory and "can destroy the aggressor's
strategic bombers even over the North Pole before they approach close enough
to fire their air-launched cruise missiles (ALCM)," says Chief of Russian
Air Force's Main Staff V. Sinitsyn.

For all of us, designers of the MiG-31 Zaslon interceptor, the song rings
true: "There's only 'MiG' between the past and the future:".
It is people who create everything in this world. What great designer teams
and beautiful personalities used to develop the MiG-31 Zaslon interceptor!
Even most prominent of them are too numerous to be mentioned here. However,
the three men whose incredible efforts resulted in the Zaslon should be
named - they are Boris Iosifovich Sapsovich, developer of the phased array
radar design and technology; Victor Konstantinovich Grishin who created the
MiG-31's general configuration - excellent manager and experimentator;
Yevgeny Yakovlevich Savitsky, chairman of the State Flight Testing
Commission.
 
[quote author=JCage]
Any ideas of which radar they are referring to when they mention those ranges and track 24?
Is it the Zaslon AM?[/quote]

They're talking about the old Zaslon-M for MiG-31M.
 
More in-action pics inside the MiG-31:

[links dead - Admin]
 
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Pit said:
JCage said:
Any ideas of which radar they are referring to when they mention those ranges and track 24?
Is it the Zaslon AM?
Click to expand...

They're talking about the old Zaslon-M for MiG-31M.
Click to expand...

Pit, any more details on the M and when did it enter service? Thats a hefty increase from 10 in TWS to 24!!
From what I had read, the M remained a toothless tiger, ie it never entered service and was restricted to prototypes.

Also, those engagement and lock on ranges seem bizarre and too high?!
The lock on is quoted as higher than the engagement (300 vs greater than 240 km) and against which target? Bomber sized?

Also what are your personal guess-estimates for the Bars-M detection and tracking ranges? Online claims seem a tad low/ conservative dont you think?
 
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Quotes from the Fedosov book:

is realized the regime [KNI] of the high pulse repetition frequency frequently by that of movement on the order of 200 kHz;
Click to expand...

is introduced the two-threshold detection of target ([valdovskoe] discrimination of the hypo
theses), on the average doubly reducing time of its detection;
Click to expand...

The development of the transmitting devices was produced taking into account the experience, obtained with the creation of complex “Kub”, in which the self-homing head of rocket worked during the continuous emission and the channel of illumination had the low level of noise. In contrast to the channel of the illumination of complex “Kub”, the transmitter [BRLS] had to work in the pulsed operation and in the considerably larger band of the carrier frequencies. The level of noise was required still smaller. Problem consisted in the fact that the harmonics of signal, brought with the pulse repetition frequency, fell into the Doppler range of receiver and was created the effect of decoy.
Click to expand...

Zone of survey (angle of elevation/azimuth), of deg:
5.5 secs 5/45
8.7 secs 20/90
The virtual displacements of the center of the zone of survey, deg ±35
Zone of tracking - semicone with the apex angle, deg:
in upper hemisphere 140
in lower hemisphere 130
Time of the displacement of ray from this position into any other, ms ~ 1,3
Dynamic range of receiver, dB 80
Width of the antenna radiation pattern, deg: 2.5
Average power of the transmitter of radar signal, kW 2.5
Power of continuous radiation of the transmitter of illumination, kW 2.0
Coefficient of receiver, dB 5.5
Diameter of antenna, mm 1100
Consumed input power, kW
alternating current 400 Hz, 200v 31
direct current 27v 2
Click to expand...
 
Regarding the 8TK IRST

Zone of survey (azimuth/angle of elevation), of deg:
in time 0.25 secs 6/6
in time 0.9 secs 30/13
Zone of tracking, deg:
along azimuth 120
on the angle of elevation 40
Click to expand...
 
That's what I mean. Radar power of MiG31 = 2.5 kW, radar power of MiG-23 = 70 kW? :-[
 
Well, average and peak are quite different things.

Regarding Zaslon compared to N-019 and N-001, the average power of both N-019/N-001 is 1kW compared to 2.5kW for Zaslon.
 
JCage this is for you ;D

Flight tests of SUV “Zaslon”
Vladimir Ilin
“Aerospace review”, №5, 2005, pages 42-43

Control system of armament (SUV) “Zaslon”, worked out for the fighter-interceptor MiG-31 - unique article, whose many characteristicss, until now, are not exceeded on the foreign analogs.
Characteristicss of complex maximally high for their time were to a considerable extent achieved due to the carrying out of multiple, now and then completely large-scale (as it is organizational, so also materially) flight tests and experiments. Some of these experiments, until now, are unique.

Should be noted the the fact that similar experiments, directed toward a increase in the possibilities of aviation complex, they were conducted also after reception MiG-31 for the armament. Let us pause only at the individual, most significant development stages of complex, carried out BY NIIP im. V.V Tikhomirov and OKB A. I. Mikoyan in the course of flight tests MiG-31.

On 15 February of 1978 in Akhtubinske took place not [povtorjonnyj], until now, not by some foreign aviation complex flying experiment on the simultaneous detection, the capture and the accompaniment of 10 aerial targets, which fly by wide front (on the order of 150 km) at different heights.

Interceptor MiG-31 executed flight at height 5000 m. of target were distributed to two groups. The first group flew at the altitude of from 8400 m to 9600 m, the second - from 1400 m to 2600 m. thus, in one experiment was evaluated the work SUV “Zaslon” both according to the targets, which fly against the background free space (sky), and along the targets, which fly (relative to interceptor) the against the background underlying (terrestrial) surface. The maximum detectable range of targets (had EPR on the order of 16 m2) was 210 kilometers.

Target Number Distance of detection/automatic target tracking Target Altitude, m
1 141,3 1400
2 162,2 9000
3 136,5 2000
4 124,8 1700
5 131,5 2600
6 137,8 9300
7 144,3 8700
8 121,5 9600
9 112,2 2300
10 115,4 8400

The total time of detection and tracking was 153,5 s. in this case the first seven targets were detected and tracked for 69,5 s. the time, spent directly on the procedure of the target of seven lock-ons, it composed 24,3 s , and 10 targets -49,05 s.

For the exclusion of the repeated target of one and the same lock-on and, as a result, “recycling” of the work of system was introduced the comparison of the coordinates newly locked on and inhibit to their repeated capture.

It must be noted, that the possibility of repeated lock on and tracking one and the same target in one flying experiment made it possible to estimate the load of calculating processes and to gather statistics according to the observation of the signals of target (mode for the experimental works) without the organization subsequently of the expensive flights of 10 of targets.

The creation of the phased antenna array (FAR) for SUV “Zaslon” made it possible not only to realize the multipurpose work of radar complex, but also to work out the application of mode of the so-called “consecutive feeler” for a increase in the range. In this case the analysis is conducted during two-four elementary temporary time (position of the ray FAR [ostajotsja] invariable). Lower and upper thresholds in each time are different. With the excess of the upper limit in each of 180 sectors of Doppler frequencies is developed the signal “target”. Consecutive feeler made it possible to obtain the gain in the range of detection of aerial targets, component approximately 20-25%. In this case entire procedure of consecutive detection is realized in special analog-digital processor.

The realization of this mode in the up-to-date digital signal processors is problematic because of the insufficient speed and the need organizing the special calculating process.

On 28 August of 1978 MiG-31 it successfully destroyed by four simultaneously released rockets R-33 of four radio-controlled airborne target.

On 18 August of 1993 was carried out a series of flying experiments on the interception of target at maximum range. In the course of the first of them the radio-controlled target, which flies at the height of 10.300 m with a velocity of 189 meters per second, was locked on by interceptor MiG-31 (flight altitude 8480 m, velocity - 669,3 meters per second) at the range if 319,5 kilometers the launch of rocket R-33 (successfully destroyed target) was carried out at the distance 228 kilometers.

Perhaps, the experiment, carried out on 21 April by 1994 became the most effective flying experiment, which entirely demonstrated the possibility of aviation complex, on the simultaneous fire of four aerial targets. As the latter were begun to operate the specially equipped fighters MiG-21 (guided from the surface control centers), that had relatively low RCS and high maneuverability.

The first target flew at the altitude of 7100 m, the second - 1720 m, the third - 2470 m, the fourth - 6230 m. the sequence of the fire of targets was determined by the program of computing system MiG-31: 4-2-3-1. All targets, which maneuvered on the course, were annihilated in several ten kilometers from the fighter-interceptor.

Thus, SUV “Zaslon” under the conditions, maximally approximating real, confirmed its unique characteristicss. It should be noted that and today aviation complex MiG-31, created still in 1968-1981 years, did not drain its evolutionary possibilities. Its modernization will make it possible to substantially increase combat potential and will attach to it the characteristicss, which correspond to requirements for the fighter-interceptors XXI of century.

For the creation SUV “Zaslon” and its modifications of 196 coworkers of NIIP they were rewarded with orders and medals of USSR.

But was begun development SUV “Zaslon” in 1968 at first it it advanced complicatedly and difficultly. All technical decisions were new: FAR, quasi-continuous emission, multipurpose work, group activities and other this now, 37 years later, they are steels customary, clear and as by itself understanding, necessary in each new development. In this case it is important to note that the fundamental technical decisions were immediately selected correctly, but their practical realization was extremely difficult task.

In the process of the work on SUV “Zaslon” was added the creative strategic formation of the specialists of different organizations. Implication to the solution of priority problem, scale of works and highest level of scientific and technological tasks drew together the specialists of the firm of the developer of – NII instrument manufacture, series plant “Leninist” and the set of enterprises and services of science, industry and client.

But by the meaningful result of development SUV “Zaslon” was creation in NIIP of scientific technical school for the development of antenna systems and radar with electronic control of ray, capable of today conducting the most complex and foremost developments both for the aviation and for the antiaircraft missile systems.
 
overscan said:
8TP/8TK IRST

Developed by a team lead by D M Khorol at Geofizika, starting in 1970.

The 8TP is installed in a retractable cylindrical housing, and uses liquid nitrogen cooling. Testing started in 1977, and was declared operational with the MiG-31 in 1981.

Scan angles of the 8TP are +-60 degrees in azimuth, +6/-13 degrees in elevation. Angular resolution is 15 minutes. Power consumption of the unit is 1.3kW, MTBF 350h, weight 124kg.

Range is about 40km against a rear aspect fighter target in military power, 100-120km against an SR-71 in full afterburner.
Click to expand...
I did this short table in hope to make a comparison among russian IRST sensors. The question mark indicates data I`m not sure about. Well, I know it`s not perfect, feel free to comment....
 

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Sorry to change the topic Mrdetonator I have a question:

When you are doing manteinance to MiG-23's IRST you need to pull off the radar as you do on Su-27S? I have readen on Aviatsia i Vremya 03/2003 special that on Su-27S manteinance of OEPS-27 was ugly due to need of removal of the RLPK-27 set to get access to the IRST. They also shared common refrigeration system. Any feedback on this on Flogger, maybe on Fulcrum?.

Sorry for change of topic.
 
Pit said:
Sorry to change the topic Mrdetonator I have a question:

When you are doing manteinance to MiG-23's IRST you need to pull off the radar as you do on Su-27S? I have readen on Aviatsia i Vremya 03/2003 special that on Su-27S manteinance of OEPS-27 was ugly due to need of removal of the RLPK-27 set to get access to the IRST. They also shared common refrigeration system. Any feedback on this on Flogger, maybe on Fulcrum?.

Sorry for change of topic.
Click to expand...
The article is funny to translate due to extensive use of slang, unless you know what they are talking about.
1. They are saying the OEPS-27 is cooled by a compressed gas (it use to be a dryed nitrogen gas which cooles the IR sensor to -196deg of Celsius). It is called "kryogen" sometimes.
2. The RLPK-27 is cooled with the "antifriz", a toxic mixture. Note: Usually, radars/targeting systems are designed to run without cooling for some minutes, from 10-20min.
3. I think they describe replacing a damaged OEPS-27 for a new one, not talking about on-field maintenance. You get access to it just by removing the radar conus. Other electronic blocks belonging to the OEPS-27 are placed behind and under the cockpit section. Although something might change since the Su-27 service entry.
4. The ShR connectors(joints) are used nowadays as well. I wish you meet them soon. ;)
5. At least you`ve heard that ground maintenance isn`t an easy job when support tooling for the aircraft is missing.

In case of the Mig-23 you have to remove the front fuselage setion too, but the radar stays on its place. The TP-23 IRST can be then unscrewed and moved downwards.
 
Re-reading such article it's clear for me they're talking on damaged OLS-27 (they were damaged due to overheating after not being switched off before landing), so you're correct. Thanks for the heads up!.

Now, where would I have to search such "ShR" connections?, in the airframe skin there is any visual aid on that?...

Are such ShR connections labelled just as "Sh" on cyrillic (yellow letters) like here:

detallesu30mk2bael10dicbe4.jpg


It's time to change place for discussion it seems ;D
 
Pit said:
Re-reading such article it's clear for me they're talking on damaged OLS-27 (they were
Now, where would I have to search such "ShR" connections?, in the airframe skin there is any visual aid on that?...
Are such ShR connections labelled just as "Sh" on cyrillic (yellow letters) like here:
Click to expand...
ShR connectors(the big, fat one on the picture) are on electrical cables which connect avionics blocks, radar blocks as well. Surely, you`ve seen them. You might find them stenciled on the skin near pylon attach points for example, mostly under the skin.
 

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Hmm, going by what I see here, I'd imagine that "antifriz" is similar to the water/glycol mix used to cool some US avionics. The ShR electrical connectors, assuming it's the large, multi-pin one in the picture definitely resemble MIL-DTL-38999 connectors, the resemblance would be even greater if these were hermetically-sealed connectors.
 
elmayerle said:
Hmm, going by what I see here, I'd imagine that "antifriz" is similar to the water/glycol mix used to cool some US avionics. The ShR electrical connectors, assuming it's the large, multi-pin one in the picture definitely resemble MIL-DTL-38999 connectors, the resemblance would be even greater if these were hermetically-sealed connectors.
Click to expand...
Yes, the most common cooling appliance used anywhere. It is a liquid mixture of ethyleneglycol,water and some additives.
The ShR stands for "Штепсельный Разъем", simply a connector standartized by corresponding GOST standards.
 
Here you have a nice overview of various electrical and data connectors (via. parallel port) standarized to Russian national standard GOST, including SNTs-23 and ONP-ZhI-8 connectors, which are also used to connect many Russian avionics suite.

http://www.uzes-iset.ru/cgi-bin/catalog/viewgroup.cgi?biggroup=4
 
Pit said:
JCage this is for you ;D

Flight tests of SUV “Zaslon”
Vladimir Ilin
“Aerospace review”, №5, 2005, pages 42-43
Click to expand...

Thanks Pit, we want more, more, more ;D ;D
 
 
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I read the Mr.Yefim Gordon's book about Mig-25 and Mig-31. In which he have mentioned to APP-46TD as the control system pod for R-46TD missile and when Mig-31 carried 2 R-40TD, it also carried an APP-46TD pod in the fourth fuselage hard point (In that case Mig-31 carried 3 R-33 only). However in Mig-31's pictures with R-46TD or R-40RD, it don't appear.

I have some queries and need your kind help to make them clear. Thank you in advance!

1 - Is APP-46TD pod true? (some people doubt if APP-46TD actually exits)

2 - R-40TD and R-40RD use inertial and ommand (I think SACLOS) in the mid-course guidance so do they be fired with or without APP-46TD support?

3 - If APP-46TD is true, why don't Mikoyan install it internally like the way they have done with Delta-NM system (radio command system for MCLOS Kh-23 missile) in Mig-27 in order to reduce the drag and save one fuselage hard-point for R-33 missile?
 
I am curious about how the original Zaslon radar compared to the more conventional pulse-doppler designs like the APG-63 PSP and AWG-9 used on the F-15s and F-14s or that era? From what I have read it was superior to the radar fitted to the Su-27 despite the original high requirements that project had.
 
Kopyo-21 said:
[...]

1 - Is APP-46TD pod true? (some people doubt if APP-46TD actually exits)

2 - R-40TD and R-40RD use inertial and ommand (I think SACLOS) in the mid-course guidance so do they be fired with or without APP-46TD support?

3 - If APP-46TD is true, why don't Mikoyan install it internally like the way they have done with Delta-NM system (radio command system for MCLOS Kh-23 missile) in Mig-27 in order to reduce the drag and save one fuselage hard-point for R-33 missile?
Click to expand...

Dear Kopyo-21, as it appears the mysterious APP-46 pod (АПП-46 in cyryllic which means Аппаратура Подготовки и Пуска дополнительного вооружения Р-40ТД) is certailny true and actually it's very real.

As you wrote ealier the APP-46 pod was carried by an MiG-31 fighter-interceptor in the fourth fuselage hard point (in that case Mig-31 carried 3 R-33 only). What is more important the APP pod was carried only on MiG-31 airframes coming from the very early production series (pre-1983 AFAIK). Since then the APP-46 pod simply vanished from late production MiG-31 fighters.

Although as it comes to APP-46 pod, IMHO a description of APP-46 which can be found on Overscan's guide to Russian Military Avionics is not entirely correct - it wasn't an "command link pod" but rather kind of podded launch preparation block device dedicated for R-40TD IR missiles. But, as I mentioned above, the APP-46 pod simply vanished from late production Foxhound's, including MiG-31B/BS and later production vatiants.

Few pictures of APP-46 pod (АПП-46: Аппаратура Подготовки и Пуска):

[pictures dead - admin]
 
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Hi John Cool, thank you very much for your information and photos. Could you please explain me more detail about what the real function of APP-46TD is? If APP-46TD is not "command link pod" so I guess it may be a "data transition pod" used to feed target data from Mig-31's sensors/FCS to R-40RD/TD missile that before were armament of Mig-25 and not compatible with early Mig-31 version.
 
From niip.ru website in 2007, specs for the Zaslon antenna.
SUV "ZASLON" PHASED ARRAY FOR MIG-31 FIGHTERS

MIG-31 fighter antenna system

The phased array for the MIG-31 fighter was developed in 1975-80. Since 1980, produced by industry. It includes two phased antenna arrays: a phased array radar operating in the X-band, and an IFF interrogator phased array operating in the L-band.

Specifications:
Scanning sector: 120 deg
Beam Installation Time : 1.28 ms
Weight : 240 kg
Uptime: > 1000 hour
Type of formed radiation patterns (DN):

- one total DN (variable width);

- two differential DNs (for monopulse direction finding)

The level of the side lobes (bl) of the total day:

Middle (first) bl <- 25db
The average level of distant bl <-43 db
Error setting beam to preset position (sko) 2.0 '
The number of emitters 1700

Phase shifter type: ferrite, mutual, with magnetic memory

Interrogator phased array for MIG-31
Type of formed beam patterns : one total, one funnel-shaped
Width of the total beam: 12 deg.
Gain
for non-deflected beam > 17. 5 dB
Number of emitters: 64

Type of phase shifter: three-bit, microstrip, on pin diodes

Waveguide distribution system: forms the optimal field distribution in the PAR aperture at high energy efficiency.
It has a compact design, small dimensions and weight.

Miniature phase shifters differ:

Low insertion loss;
Stable phase characteristics;
Small mass;
Low energy management.
Click to expand...
 
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Too bad that there seems to be no information on operating modes and their respective parameters being released so far.

As knowing the pulsewidth and the respective PRF being used in the modes, one can actually estimate the duty cycle.
 
Dear Colleagues, what kind of system, or 'complex' as it's named in Russia, was used for mid-course update feeds to an R-37 missile that was launched and enroute to a target? Was is a one-way or a two-way link?
 
so Mig-31 haven't got new radar yet? they could have just put Irbis-E on it I think
 
Ronny said:
so Mig-31 haven't got new radar yet? they could have just put Irbis-E on it I think
Click to expand...
The Su-35 gets its 20kw power from employing 2 TWT (as say the ASG-18 on the YF-12, oh so many years ago) which also gives wider channel coverage and greater ECCM options but only insofar as 'half of each' they are stepped between lower and upper X band (H/I Band) with an overlap in the middle.

My understanding is that this causes coherency and frequency lock issues which effects S/Nr at the PSP which in turn denies the use of a high end radar dataprocessor.

In any case, the VKS has lost a couple Su-35s over Ukraine under circumstances where the likelihood of techint recovery was almost certain. Putting No-35 Irbis tech into the Zaslon is thus kind've a yeah but...no deal at this point. The No-36 Byelka of the Su-57 would be a better option or one of the Type 1245/1248 series (Chinese) AESA if the russians cannot do the tech development.

The SBI-16 Zaslon gains it's power by virtue of being FMICW.

Meaning it operates at high PRF equivalent, all the time. At 2,600kg, it weighs almost twice as much as the AWG-9 and there is a good chance that that is at least partially a PAO cooling loop for a radar that operates at scaled outputs approaching 30kw (you can't measure FMICW by duty cycle).

This is why it has such an enormous range. This is why it can track TBM targets of .1m2 and guide missiles on them with closures above Mach 7.

This is why Zaslon was built to track and kill .3-.5m2 TLAM-N and .25m2 AGM-86B (mod 1) ALCM. And later was adapted to track the .01m2 AGM-129.

Even equipped with the older R-33 missile, it was never intended solely as a 'bomber/tanker/C4ISR killer' but rather to kill small, agile, targets over heavy terrain clutter, after handoff from central Russian EWR, acting as part of the Russian national air defense system in a nuclear environment.

In this, it is necessary to understand that FMICW radars work to a nominally 'older' style of LDSD capability. Where Pulse Doppler is based on eliminating anything that isn't generating frequency compression by movement, leaving a 'blank screen' effect.

FMICW takes an alternative, additive, approach of measuring real beam flashback from the immediate terrain under illumination and then looking harder at anything which is higher than the average db of that averaged return. This was standard as a means of locking up targets below the jet in the F-4 era and the machine-tracking was actually quite good at it, though the WSO/RIO needed effectively a video trick to adjust target display contrasts in seeing the initial bright-blip (which the filter also automated).

This is actually innately superior to PD tracking, provided you have an EPAR which can rapidly refresh and frequency surf the given illumination zone while having a large enough framing buffer that you can average out aspect shifts and chaff blooms etc. by a maneuvering target. A PD system is simply too vulnerable to beaming and the null speed doppler filter. Whereas a FMICW system will always see additive differences between base clutter and target multiplier, even if the latter is negative as a function of shadowing (due to multipath).
FMICW always has issues with range finding and ECCM inserts as it depends on specific waveform encoding to split targets into range gated filter stacks. But, conversely, it's never bothered by hi/lo interleave in determining range uncertainty, simply because it has such fast scanning.

The original Zaslon, which Adolf Tolkachev compromised to the West, being a product of the 1970s, was almost certainly an analogue system which was limited in it's tracking capabilities (numbers and active scan waveforms). But the later Zaslon A introduced a digital Argonne 5/7/11/15 and then the Baget radar dataprocessor which are actually pretty good.

Over Ukraine, one of the key commonalities of the rash of R-37 kills which has all but denuded the ZPU of fighter inventory (after 30 days of 6 missiles fired per day, even at .25 SSPK, we're talking ~45 downings with one Foxhound pilot claiming 9 kills...) has been the lack of hard track warning.

Back in the day (1980s) a lot of 'new' RWR like the ALR-56 did not pick up the signal or at least did not treat it as AI. This led to scenarios like the 36th TFW out of Bitburg being constantly bushwacked in their new-hotness F-15As by older-and-cunninger F-4Es of the Wolfhounds 'Royal Squadron' because the Phantom WSOs would unplug the APQ-120 breaker and perform the lock-on (from a zoom climb) with the TISEO. Then flip on the CW for Sparrow illumination and zap the Rodans without a hard pulse track since the APQ-120 was linked to the optics boresight and performing angle off calculations which the CW floods sent to the missile.

Something similar may be going on with the Zaslon/Axehead pairing in that the latter missile _does_ use PD as a range:rate lead steering mechanism and, with the parent radar offering radio correction updates and the VLRAAM using it's incredibly high cruise speed, the missile may actually be engaging in a form of track via missile as the datalink is confirmed to be two-way. TVM flies an inertial flight path for part of the trip, sees the SARH reflection and begins homing (for the R-37M) around 18nm and then says: "Okay, is _this the guy_" which the radar's long range angle tracking with the Zaslon confirms as the missile again uses it's spectacular (Mach 6.7) kinematics to always positive-lead steer to a high RCS aspect. And then, as LOS-R goes to zero, activates a separate, Ka band, active seeker which snaps the missile back to collision lead and scores the hit.

Again, this corresponds with what Ukrainian pilots have said it the 'bolt from blue' effect of sudden kills with no passive threat warning as the SARH becomes ARH.

Finally, the Russians have long used idiomatic scientific expressions which have rather different meanings in English or German (the two engineering languages) to strongly imply that the Zaslon is capable of not just datalink shared tracking but true _cooperative sensing_ which is to say that Foxhounds up to 200km apart can link scans and tick / tock \ derive common triangulated reads of target bearing from enhanced/multi-aspect illumination.

Again, if true, with such powerful baseline systems operating in a mode similar to the USNs CEC mode, flinging dual mode, dual band, hypervelocity VLRAAM; it would go a long ways towards explaining why the Russians are both confident in their ability to track stealth and able to achieve long range intercepts of 217km or more against fastjets, low in the clutter.

The Russians always admired the F-14, it fits in with their 'artillery rocket' mindset. When Belenko defected in the Foxbat, we gave him a fam ride in one and he said: 'How do you even get close...?'.

The MiG-31 is the answer to that question and, over multiple upgrades, now has an SBI-16AM radar weapons system specifically optimized to the delivery of the R-37M in three modes:

Anti-fighter, in which the missiles fly a direct trajectory and shift immediately to ARH in what we would call Fire And Forget or Skating.

Radio-corrected inertial, which is the primary long range mode for SARH-TVM.

And 'Reprogrammable' which has alternately been asserted to mean the ability to set a homing point (airfield baselane) where target activity is expected to be. Or/and a method of seconding illumination authority to another aircraft.

When the original K-37 (AA-X-13 Arrow) program achieved it's 308km, 1994, hit, the distance was so great that an intermediate Su-30 was used (as was the No-11 Bars-M antenna frontend in the MiG-31BM upgrade) to provide the midcourse update as the launching Foxhound was literally firing beyond its baseline tracking range.

While at least two of the operational R-37M kills are known to have been attributed to the Su-57 Felon. Of course the Axehead itself is a third of a meter shorter than the testbed missile. But the engagement circumstances and supposed LPI/LPD capability of the No-36 radar do highlight a possible 'feature not workaround' intentional operation mode which simply maximizes the missile kinematic capabilities while perhaps compensating for any residual Su-57 signature issues as well.

The point here is that the Russians are always methodical and careful with their planned mission increment changes in capabilities, rather than simply the 'More range, speed, or ECCM?' 'Yes!' approach of pushing boundaries for its own sake, in the West. They have to carefully weigh capabilities improvements and so have time to bring things all together.

Given the K-37 program nominally ended in 1998, yet incremental development continued until a 2016-18 service debut of the R-37M; it would not be at all impossible for the Zaslon to be what it (now) is because the Axehead is what the Russians deemed necessary as an ultimate counter to the AMRAAM evolutionary potential. All the way back in 1988 when development first started.

The very notion that Zaslon could grow that far is a hallmark of how capable the system, itself an artifact of a 1970s, pre-digital, era really may be. As a multi-role set, the No-35 is likely too compromised to be as good, in the pure air defense mission.
 
LEG said:
Ronny said:
so Mig-31 haven't got new radar yet? they could have just put Irbis-E on it I think
Click to expand...
The Su-35 gets its 20kw power from employing 2 TWT (as say the ASG-18 on the YF-12, oh so many years ago) which also gives wider channel coverage and greater ECCM options but only insofar as 'half of each' they are stepped between lower and upper X band (H/I Band) with an overlap in the middle.

My understanding is that this causes coherency and frequency lock issues which effects S/Nr at the PSP which in turn denies the use of a high end radar dataprocessor.

In any case, the VKS has lost a couple Su-35s over Ukraine under circumstances where the likelihood of techint recovery was almost certain. Putting No-35 Irbis tech into the Zaslon is thus kind've a yeah but...no deal at this point. The No-36 Byelka of the Su-57 would be a better option or one of the Type 1245/1248 series (Chinese) AESA if the russians cannot do the tech development.

The SBI-16 Zaslon gains it's power by virtue of being FMICW.

Meaning it operates at high PRF equivalent, all the time. At 2,600kg, it weighs almost twice as much as the AWG-9 and there is a good chance that that is at least partially a PAO cooling loop for a radar that operates at scaled outputs approaching 30kw (you can't measure FMICW by duty cycle).

This is why it has such an enormous range. This is why it can track TBM targets of .1m2 and guide missiles on them with closures above Mach 7.

This is why Zaslon was built to track and kill .3-.5m2 TLAM-N and .25m2 AGM-86B (mod 1) ALCM. And later was adapted to track the .01m2 AGM-129.

Even equipped with the older R-33 missile, it was never intended solely as a 'bomber/tanker/C4ISR killer' but rather to kill small, agile, targets over heavy terrain clutter, after handoff from central Russian EWR, acting as part of the Russian national air defense system in a nuclear environment.

In this, it is necessary to understand that FMICW radars work to a nominally 'older' style of LDSD capability. Where Pulse Doppler is based on eliminating anything that isn't generating frequency compression by movement, leaving a 'blank screen' effect.

FMICW takes an alternative, additive, approach of measuring real beam flashback from the immediate terrain under illumination and then looking harder at anything which is higher than the average db of that averaged return. This was standard as a means of locking up targets below the jet in the F-4 era and the machine-tracking was actually quite good at it, though the WSO/RIO needed effectively a video trick to adjust target display contrasts in seeing the initial bright-blip (which the filter also automated).

This is actually innately superior to PD tracking, provided you have an EPAR which can rapidly refresh and frequency surf the given illumination zone while having a large enough framing buffer that you can average out aspect shifts and chaff blooms etc. by a maneuvering target. A PD system is simply too vulnerable to beaming and the null speed doppler filter. Whereas a FMICW system will always see additive differences between base clutter and target multiplier, even if the latter is negative as a function of shadowing (due to multipath).
FMICW always has issues with range finding and ECCM inserts as it depends on specific waveform encoding to split targets into range gated filter stacks. But, conversely, it's never bothered by hi/lo interleave in determining range uncertainty, simply because it has such fast scanning.

The original Zaslon, which Adolf Tolkachev compromised to the West, being a product of the 1970s, was almost certainly an analogue system which was limited in it's tracking capabilities (numbers and active scan waveforms). But the later Zaslon A introduced a digital Argonne 5/7/11/15 and then the Baget radar dataprocessor which are actually pretty good.

Over Ukraine, one of the key commonalities of the rash of R-37 kills which has all but denuded the ZPU of fighter inventory (after 30 days of 6 missiles fired per day, even at .25 SSPK, we're talking ~45 downings with one Foxhound pilot claiming 9 kills...) has been the lack of hard track warning.

Back in the day (1980s) a lot of 'new' RWR like the ALR-56 did not pick up the signal or at least did not treat it as AI. This led to scenarios like the 36th TFW out of Bitburg being constantly bushwacked in their new-hotness F-15As by older-and-cunninger F-4Es of the Wolfhounds 'Royal Squadron' because the Phantom WSOs would unplug the APQ-120 breaker and perform the lock-on (from a zoom climb) with the TISEO. Then flip on the CW for Sparrow illumination and zap the Rodans without a hard pulse track since the APQ-120 was linked to the optics boresight and performing angle off calculations which the CW floods sent to the missile.

Something similar may be going on with the Zaslon/Axehead pairing in that the latter missile _does_ use PD as a range:rate lead steering mechanism and, with the parent radar offering radio correction updates and the VLRAAM using it's incredibly high cruise speed, the missile may actually be engaging in a form of track via missile as the datalink is confirmed to be two-way. TVM flies an inertial flight path for part of the trip, sees the SARH reflection and begins homing (for the R-37M) around 18nm and then says: "Okay, is _this the guy_" which the radar's long range angle tracking with the Zaslon confirms as the missile again uses it's spectacular (Mach 6.7) kinematics to always positive-lead steer to a high RCS aspect. And then, as LOS-R goes to zero, activates a separate, Ka band, active seeker which snaps the missile back to collision lead and scores the hit.

Again, this corresponds with what Ukrainian pilots have said it the 'bolt from blue' effect of sudden kills with no passive threat warning as the SARH becomes ARH.

Finally, the Russians have long used idiomatic scientific expressions which have rather different meanings in English or German (the two engineering languages) to strongly imply that the Zaslon is capable of not just datalink shared tracking but true _cooperative sensing_ which is to say that Foxhounds up to 200km apart can link scans and tick / tock \ derive common triangulated reads of target bearing from enhanced/multi-aspect illumination.

Again, if true, with such powerful baseline systems operating in a mode similar to the USNs CEC mode, flinging dual mode, dual band, hypervelocity VLRAAM; it would go a long ways towards explaining why the Russians are both confident in their ability to track stealth and able to achieve long range intercepts of 217km or more against fastjets, low in the clutter.

The Russians always admired the F-14, it fits in with their 'artillery rocket' mindset. When Belenko defected in the Foxbat, we gave him a fam ride in one and he said: 'How do you even get close...?'.

The MiG-31 is the answer to that question and, over multiple upgrades, now has an SBI-16AM radar weapons system specifically optimized to the delivery of the R-37M in three modes:

Anti-fighter, in which the missiles fly a direct trajectory and shift immediately to ARH in what we would call Fire And Forget or Skating.

Radio-corrected inertial, which is the primary long range mode for SARH-TVM.

And 'Reprogrammable' which has alternately been asserted to mean the ability to set a homing point (airfield baselane) where target activity is expected to be. Or/and a method of seconding illumination authority to another aircraft.

When the original K-37 (AA-X-13 Arrow) program achieved it's 308km, 1994, hit, the distance was so great that an intermediate Su-30 was used (as was the No-11 Bars-M antenna frontend in the MiG-31BM upgrade) to provide the midcourse update as the launching Foxhound was literally firing beyond its baseline tracking range.

While at least two of the operational R-37M kills are known to have been attributed to the Su-57 Felon. Of course the Axehead itself is a third of a meter shorter than the testbed missile. But the engagement circumstances and supposed LPI/LPD capability of the No-36 radar do highlight a possible 'feature not workaround' intentional operation mode which simply maximizes the missile kinematic capabilities while perhaps compensating for any residual Su-57 signature issues as well.

The point here is that the Russians are always methodical and careful with their planned mission increment changes in capabilities, rather than simply the 'More range, speed, or ECCM?' 'Yes!' approach of pushing boundaries for its own sake, in the West. They have to carefully weigh capabilities improvements and so have time to bring things all together.

Given the K-37 program nominally ended in 1998, yet incremental development continued until a 2016-18 service debut of the R-37M; it would not be at all impossible for the Zaslon to be what it (now) is because the Axehead is what the Russians deemed necessary as an ultimate counter to the AMRAAM evolutionary potential. All the way back in 1988 when development first started.

The very notion that Zaslon could grow that far is a hallmark of how capable the system, itself an artifact of a 1970s, pre-digital, era really may be. As a multi-role set, the No-35 is likely too compromised to be as good, in the pure air defense mission.
Click to expand...
Why do I feel like you just put a bunch of acronym together randomly ?
"The SBI-16 Zaslon gains it's power by virtue of being FMICW" => no, Zalson is a pulse doppler radar

"FMICW takes an alternative, additive, approach of measuring real beam flashback from the immediate terrain under illumination and then looking harder at anything which is higher than the average db of that averaged return." => if that was the case, a mountain would have higher return than any aircraft and therefore you can never pick up anything at lower altitude?

"This is actually innately superior to PD tracking, provided you have an EPAR which can rapidly refresh and frequency surf the given illumination zone while having a large enough framing buffer that you can average out aspect shifts and chaff blooms etc. by a maneuvering target. A PD system is simply too vulnerable to beaming and the null speed doppler filter. Whereas a FMICW system will always see additive differences between base clutter and target multiplier, even if the latter is negative as a function of shadowing (due to multipath)." => this honestly just look like a bunch of random acronym put together, PD is pulse doppler, FMICW is Frequency modulated interrupted continuous wave. But the rest make no sense at all.

"Over Ukraine, one of the key commonalities of the rash of R-37 kills which has all but denuded the ZPU of fighter inventory (after 30 days of 6 missiles fired per day, even at .25 SSPK, we're talking ~45 downings with one Foxhound pilot claiming 9 kills...) has been the lack of hard track warning."=> I highly skeptical at the notion that R-37 downed 45 aircraft in Ukraine

Finally, the Russians have long used idiomatic scientific expressions which have rather different meanings in English or German (the two engineering languages) to strongly imply that the Zaslon is capable of not just datalink shared tracking but true _cooperative sensing_ which is to say that Foxhounds up to 200km apart can link scans and tick / tock \ derive common triangulated reads of target bearing from enhanced/multi-aspect illumination.=> Iam pretty sure there is no source for this. Zaslon can share data basically the same way normal aircraft share datalink
 
For the purposes of whether Zaslon is an "FMICW" radar, we should be clear on what that means.

From GEC material, the FMICW Foxhunter is a high PRF pulse doppler radar with a high duty cycle of 0.5. Its chosen PRF is very high (above 100KHz), which makes it effectively clutter-free for closing targets and great at measuring target velocity, but unfortunately resulting in very little ability to measure range unambiguously as the gap between pulses is so small, any target beyond a few miles might be from one of many sent pulses, resulting in range ambiguity.

Therefore a stable low frequency, frequency modulation signal is superimposed on the high PRF transmission, which allows the radar to calculate the range based on the modulation present in received pulses to determine when the pulse was sent, and hence how far away the target is.

FMICW is not the only way to recover range information from a high PRF transmission. You can vary the PRF, for example, as is typically done with medium PRF pulse-doppler radars.

The advantages of a high PRF radar with an FMICW ranging approach is simplified processing and a relatively simple solution of lookdown radar for the most dangerous class of targets (closing in range).

Later radars with better signal processing capability tend to use a variety of PRFs and various range measurement techniques and lower duty cycles. FMICW is a "hack" whose time should be effectively over.

The first question is, what is the evidence Zaslon is an FMICW system?
 

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