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To my knowledge the TGS-23 seeker of the R-23T uses Indium-Arsenide (InAs) nitrogen cooled down to 63K.
R-23, R-24 & R-27 AAM
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Can you share the info on the red-top?
And yes, this doc sates the R60 was uncooled, while the 60M was cooled. Given that the overall detectivity of uncooled PbSe is not really great (though in the MWIR band), and marginally cooled PbSe is significantly better (and pushes the response further into the cooler parts of the MWIR band) It explains the general behavior you can attribute to the missile, i.e. uncooled PbSe would like be able only to see/detect the hotter parts of the engines, much like cooled PbS, while cooled PbSe would be more comparable (though inferior in specific detectivity) to InSb materials.
Interesting. You sure its not like 163K? The detectivity at lower temperatures shifts further into the NIR for InAs. So you'd be loosing all aspect performance.
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I can confirm that. The seeker of the R-60M was Peltier cooled and R-60 was uncooled.
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I have to correct me. It is 78K (195°C).
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Indium-Arsenide has very similar band capabilities to PbS at room temperature I believe. What would be the advantage?
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And actually when its cooled its moving the wrong way. So I'm really curious as to why InAs would be used.
Thanks, also is there something on the matra 530IR? I wonder if there was any sort of tech transfer going around with Frech/Brits/US missiles for these early IR seekers.
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The British early seeker work was initially based on testing of Gerrman IR equipment. It was also wholly separate from US and French IR development as far as I can see. The UK did consider collaboration with the French on radar seekers in the 1960s.
Mostly likely IR seeker development was based on original German equipment in all countries?
Mostly likely IR seeker development was based on original German equipment in all countries?
Well the British had their own IR testing establishment that produced usable IR scopes for Army/Naval use. And IIRC the optical properties of InSb was a British discovery in '54 IIRC. But yeah everyone cribbed off the German wartime work.
In regards to the AIM-9 I don't think German research played much of a role if any as when Dr. McLean initiated his project NOTS had actually been barred from developing AAMs due to a disastrous attempt at developing an IR seeker IIRC.
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The early documents on British airborne infrared seeker development specifically mention testing German PbS sensors as a first step. There was a robust British development of infrared to be sure from a basic science level upwards.
PbS as a detector material was known from the 30's onward, and really from what I know china lake didn't really do much actual development of the detector materials, that was sort-of farmed out to the universities. The Aim-9D for example was supposed to have a PbSe detector but it didn't work out for whatever reason. But McLeans engineering genius on the sidewinder seeker and how it worked had little to do with the actual detector material.
That isn't exactly perfect but it is good information. I would like to know more about the R-27 so if anyone ever comes up with a full or partial manual / description for it like there is for the R-24 manual.. I would like to see it thanks.
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I have some stuff, what specifically are you interested in? R-27 guidance really works the same for Su-27 and MiG-29. The extended range versions don't do anything different or special with guidance techniques to my knowledge. Some work was done on lofted flight profiles (R-27EM) but I'm not sure if those versions ever made it to service.
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No. As soon as Soviet then Russians figure that they can move to R-77. Alternative schemes were just died on tracks. Including even the R-27AE.
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An active seeker for the R-27 was developed and displayed at several airshows but not sure if it ever get actually tested.
An unusual way to use the R-27T by Yemeni Houthis.
www.thedrive.com
Aircraft Attacked Over Yemen With R-27 Air-to-Air Missile Modified Into A SAM
Houthi rebels have converted missile stocks intended for the country's MiG-29s into surface-to-air missiles, possibly with the help of Iran.
www.thedrive.com
For all we know they may've actually tried to make an active seeker version of the AA-10 Alamo in place of the AA-12 Adder but weren't able to due to internal and/or external factors, as far as I know Ukraine still has the technical talent for this type of work.
Ainen
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It isn't as much they didn't try as they simply never had money/resources to.
They probably could attempt to do it right now, with the economy on a war footing(=money) - but at this point, it's more or less clear that the future of PSU is Western. The development cycle will be just too long.
Battlefield SAM sounds like a far better investment, one that West visibly struggles to provide.
from what mig-29 it is?
That's MiG-29 not mig-29.
What is the lock on range in all aspect in the R73?
The su27sk manual says about 5km for a small cold target, but doesn't state at what altitude
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Hi Paul, I read somewhere that E versions were not in fact extended range versions but extended velocity versions. The idea was to shot in response to Sparrow but due to higher speed destroy carrier /radar before Sparow reach its target. Extended range was byproduct of overall higher energy that E version contain in fuel.
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No. It was specifically intended to outrange the Sparrow, for Su-27 requirement. It basically replaced the R-33, which was initially intended as the Su-27's 'long range' option. However, it does have a higher thrust/weight ratio than the R-27 as well as a sustainer, so it might reach a higher maximum velocity as well.
Due to limitations in Soviet seekers and radars, they were also forced into lock on after launch even just to match Sparrow range, let alone exceed it.
Due to limitations in Soviet seekers and radars, they were also forced into lock on after launch even just to match Sparrow range, let alone exceed it.
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So did they have data-links to enable a proper LOAL mode?
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Yes, correction commands were transmitted via the host aircraft radar signal (as Barker codes I think?) and received by the rear-facing reference signal receivers on the missile seekers. There wasn't a separate data link antenna. That's also why the IR versions did not have the same capability and had to be locked on before launch.
I can't see why the IR version of the AA-10 couldn't have kept the reference-aerial to use it as a datalink to enable a LOAL mode.
Edit: is this what you meant by Barker codes and do you have any links about this use of it?
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It didn't though. The rear-facing aerials are missing. They are part of the SARH guidance system - the seeker gets reflected signal from the target and the reference signal directly from the illuminating radar.
Not sure yet how the course correction process worked, whether it was transmitting the updated coordinates of the target in 3d space and getting the missile to work out how to find it or something less taxing on the missile (i.e. using the aircraft's computer to work out that stuff and then just sending "steer left 2 degrees", "antenna right 1 degree" type commands or what.
I would imagine it would need to retain some portion of the SARH seeker hardware in place or a totally different system to be developed.
The developers clearly decided not to bother with this.
Yep. I'll dig up the original documentation - it was auto-translated from Russian. Its possible the barker codes are for syncronisation.
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General information about RTS missile control
Purpose, composition and principles of construction
A radio control system (SRU) is a complex of functionally connected radio technical and other technical means, designed for automatic or semi-automatic control of an object (aircraft, missile) with the aim of bringing it to a given point or to a given position relative to another object in action destabilizing factors.
The information subsystem issues signals of missile deviation from the desired trajectory. The sources of information are radars, IR direction finders, other means of obtaining information about the target, radio technical information transmission systems, sensors of the parameters of the missile flight, the state of the missile and its subsystems, etc.. By processing the information with the appropriate algorithms of the computer (analog or digital), the deviation signal (SV ) rockets from the desired trajectory.
The control subsystem (missile control system - SUR) directly affects the missile control bodies (on the control object) in accordance with the SV to eliminate guidance errors.
During automatic missile control, the information subsystem equipment is located on the missile.
In case of non-automatic control with the participation of the operator, the equipment of the information subsystem is placed on the rocket and on the rocket carrier. The trajectory control signal generator (FSTU) provides the operator with information about the deviation of the missile from the desired trajectory by analyzing information about the relative position of the missile and the target. Based on this information, the operator adjusts the missile's flight using the control command generator (CCM). Control commands are transmitted to the missile through the command radio control line (CRC).
Destabilizing factors lead to deviation of the rocket from the desired trajectory and flight profile.
The missile control system (MSC) detects these deviations and produces control parameters ΔГ and ΔВ in the horizontal and vertical planes, which ensure the elimination of these deviations.
The deviation of the missile from the desired trajectory or flight profile is monitored by the information system of the missile or its carrier and is used to issue control commands that keep the missile on a given trajectory. During normal operation of the SUR
Δ ≈ 0.
In autonomous SUR, the control parameter Δ is formed by comparing the programmed (set) parameters of the rocket’s own movement (position) with the actual ones, which are controlled with the help of on-board information systems - gyroscopic, inertial, astronavigation, Doppler, radar, radionavigation, television, radio astronomy, barometric, control according to guidelines and others.
Autonomous SUDs are used to control missiles in order to impress stationary targets with known coordinates, as well as during the first stage of the missile's flight immediately after its launch to impress moving targets in non-autonomous and combined SUDs. In the latter case, thanks to the use of an autonomous air defense system at the first stage of its flight, the possible range of missile launches is significantly increased.
In non-autonomous SUR, the information received from the target (homing system) or from the control point (command radio control system, radio zone control system) is used to form the control parameter Δ.
In homing systems, missile control commands are formed based on the analysis of signals coming from the target - optical, infrared, radar, and the target's own radiation. Radar homing systems can be active, semi-active or passive.
In command control systems, the corresponding commands are formed on the carrier and transmitted to the missile via the command radio line. The measuring equipment of the information subsystem is placed completely on the carrier or partially on the rocket (for example, a television camera) and on the carrier.
In radio zone control systems, the carrier equipment creates a radio zone that sets the trajectory of the missile. The on-board equipment of the missile determines the current deviation of the missile from the axis of the radio zone for the formation of control commands.
Non-autonomous anti-missile systems are used to control missiles when hitting moving and stationary targets.
In combined SUR, both methods of obtaining and using information are used to form the control parameter Δ. Combined missile control systems by using the most rational control system at each stage of the missile's flight ensure the maximum quality of missile control and a long launch range. For example, targeting a long-range missile is carried out first according to the program, then by semi-active homing and finally by active homing.
In the pulse radiation radar, the illumination signal of the on-board fighter radar of the fP+FD frequency reflected by the target is followed in direction by the missile coordinator - the control parameter φ is determined or the additional selection of the target by range is carried out by comparing the moments of reception of the direct (tail antenna) and reflected (nose antenna) illumination signals.
In the radar of quasi-continuous radiation, reflected signals are selected by speed by comparing the frequencies of direct (tail antenna) and reflected (nose antenna) illumination signals. Modern missile coordinators are monopulse tracking direction finders. Thanks to this:
the coordinator is insensitive to amplitude-modulated interference created by the target; high accuracy of bearing is ensured.
Target selection by range or speed of approach during pulsed radiation is carried out by range or speed tracking systems.
On launch, the homing head (GOS) against the background of powerful signals from the aircraft's on-board radar transmitter cannot receive weak reflected signals. Therefore, only after launching the GOS to detect the attacked target, it searches for it. In order to avoid errors (when the target is not the same) and to speed up the start of homing, the target indication by angular coordinates and speed (range) is issued and memorized on the suspension in the GPS.
After launching the missile, the target can change its flight parameters. Therefore, a special radio correction channel is introduced to transmit changes in target parameters to the missile.
For coordinators, errors such as angular noise are characteristic, which are the result of the fact that when approaching the target, its angular dimensions increase and the target is no longer perceived as a point. This is taken into account by the missile control system algorithm.
Advantages of semi-active GOS:
long range of action with small size and weight;
independence from weather conditions and the target's own radiation;
the possibility of additional selection by speed (distance);
the possibility of correcting the parameters of the missile control channel after its launch.
Disadvantages of semi-active GOS:
the need to illuminate the target until the moment of its impression;
the possibility of creating interference on the reference signal channel (radio correction);
the complexity of the rocket equipment.
The passive GOS coordinator accompanies the target by its own (thermal) radiation or by the radiation of the radio-electronic equipment of the target.
Powerful thermal infrared (IR) radiation in the range of 1.8 ... 6 μm is created by the power plants of airplanes and helicopters mainly in their rear hemisphere (ZNS). The high spatial selection and sensitivity of thermal homing heads (TSH) allow to identify and track the target in its runway even before launch. After launch, such a passive missile homing system operates autonomously.
Passive radar homing heads (PRGS) are used in air-to-air missiles to impress emitting radio-electronic objects (RADS). As in the TGS, targeting, detection and capture of the target for tracking is carried out before the launch of the missile.
The launch is carried out when the permitted launch range is reached. The starting moment is determined by indirect methods - by ground reference points with known coordinates of the object, by the basic or angular method with unknown coordinates.
The flight of the rocket is carried out at a reference height. The moment of the start of diving on the target is determined upon reaching the calculated angle of elevation.
3. Command radio control systems
The principle of operation of command systems
Alignment of the control point (aircraft – missile carrier), target (biased point) and missile on the same straight line is provided by PU commands, which are generated based on the results of monitoring the current position of the missile relative to the given flight path.
The control parameter is the angular ε or linear h deviation of the missile from the given trajectory.
The angular deviation ε is controlled by the carrier's on-board equipment by tracking the directions to the target and the missile.
Linear deviation is calculated: h=ε·D. The current range D of the missile is monitored by the range finder of the carrier or calculated: D=∫V(t)·dt or D≈VSer·t, where VSer and t are the average speed of the missile and its flight time after launch.
The current value of the control parameter is transmitted to the missile via a radio telemetry line.
A possible option is when the control parameter is calculated by the rocket equipment. In this case, the current results of monitoring the position of the missile and the target are transmitted to the missile via the telemetry line.
The carrier receives information about the coordinates of the target εЦ, ДЦ and the missile εР, DR with the help of radar coordinates of the target (VKC) and the missile (VKR). VKTS is an active-type radar, and VKR is an active-response radar. The current coordinates of the target and the missile are used by the control parameter calculator (ОбчΔ) to determine the missile control parameter.
The current value of the control parameter and other information in the control command generator (CCM) are converted into control commands.
The transmitting part of the multi-channel command radio control line (KRU) transmits these commands on the operating frequency. From the received radio signal, the receiving part of the missile control unit issues control commands for the missile control system (MSC). The encoder (Ш) and decoder (ДШ) of the switchgear are means of protection against interference.
The command radio control system of the fighter
In the weapon control systems of modern fighter jets, command radio control of missiles after their launch is used to correct missile control algorithms at the stage from missile launch to the start of target tracking with missile homing heads.
Control commands are formed and transmitted over the target illumination radio channel by semi-active radar homing missiles.
A base-3 code is sometimes used to transmit air-to-air missile control commands; its alphabet consists of the symbols "-1", "0" and "+1".
Codes with a base of 2 can be used to encode the signals of each of the three symbols, for example, the 5-bit code 1-1-1-0-1.
In the ternary system, a “direct” code is used, that is, the sequence of symbols 1-1-1-0-1, a “reverse” code, which is an inversion of the direct code, that is, a sequence of symbols 0-0-0-1-0, and the so-called “ "zero" code, in which there is no coding of primary signals. If frequency modulation of the signal with frequencies Fm1 and Fm2, which correspond to elementary binary symbols "0" and "1" of the code, is used for coding, then signals according to the table will correspond to each of the three symbols of the alphabet.
With two-digit words in the triple number system, it is possible, for example, to convey the set of six corrections given in the table with a value that is a multiple of of some of the missile control parameters.
The remaining codes (-1; +1) and (+1; -1) can be used to transmit two more one-time commands.
Source:
Section IV
"Operation and repair of radio-electronic equipment of airplanes, helicopters and air missiles"
Topic 14. "Radio technical missile control systems"
Associate professor of the department candidate of technical sciences, associate professor V. A. Voychuk
Kyiv 2012
(Its from a Ukrainian course on the MiG-29 and Su-27 avionics systems)
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The seeker of the missile locked a target after launching. R-23 got angles from the plane before starting( very close to ideology of Sparrow 7E or Sky Flash). R-24 got angels, distance and velocity of a target from the plane which gave possibility to increase distance of a lanch.
