Information about F-35 nozzle are available, including pattern
http://www.f-16.net/f-16_versions_article20.html
https://www.google.com/patents/US20090072044
https://www.google.com/patents/US6983602
http://www.google.com.gi/patents/US20020036241
https://www.google.ch/patents/US6398129
I agree that F-22 on supercruise will have lesser tail signature than F-35 at 100% AB. But i don't think either will be particularly stealthy when they ran away. I think signature is the most important when you sneak on enemy.
Btw, reduce nozzle area will lengthen the exhaust trail because the flow velocity is higher
Datalink is around for a while, stealth datalink such as MADL is a recent invention.
Not really..., just in uninformed minds.
The Gripen TIDLS is described here:
https://m.blog.naver.com/jskimadd/10103300031
”One Gripen can provide radar sensing for four of its colleagues, allowing a single fighter to track a target, while the others use the data for a stealthy attack. TIDLS also permits multiple fighters to quickly and accurately lock onto a target's track through triangulation from several radars; or allows one fighter to jam a target while another tracks it; or allows multiple fighters to use different radar frequencies collaboratively to "burn through" jamming transmissions. TIDLS also gives the Gripen transparent access to the SAAB-Ericsson 340B Erieye "mini-AWACs" aircraft, as well as the overall ground command and control system. This system provides Sweden with an impressive defensive capability at a cost that, though still high, is less than that of comparable systems elsewhere.
TIDLS can connect up to four aircraft in a full-time two-way link. It has a range of 500 km and is highly resistant to jamming; almost the only way to jam the system is to position a jammer aircraft directly between the two communicating Gripens. Its basic modes include the ability to display the position, bearing, and speed of all four aircraft in a formation, including basic status information such as fuel and weapons state. The TIDLS is fundamentally different from broadcast-style links like Link 16. It serves fewer users but links them more closely together, exchanging much more data, and operating much closer to real time.
TIDLS information, along with radar, EW, and mapping data, appears on the central MFD. The display reflects complete sensor fusion: a target that is being tracked by multiple sources is one target on the screen. Detailed symbols distinguish between friendlies, hostiles, and unidentified targets and show who has targeted whom.
Today, Sweden is the only country that is flying with a link of this kind.
The Flygvapnet has already proven some of the tactical advantages of the link, including the ability to spread the formation over a much wider area. Visual contact between the fighters is no longer necessary, because the datalink shows the position of each aircraft. Leader and wingman roles are different: the pilot in the best position makes the attack, and the fact that he has targeted the enemy is immediately communicated to the three other aircraft.
A basic use of the datalink is "silent attack." An adversary may be aware that he is being tracked by a fighter radar that is outside missile range. He may not be aware that another, closer fighter is receiving that tracking data and is preparing for a missile launch without using its own radar. After launch, the shooter can break and escape, while the other fighter continues to pass tracking data to the missile. In tests, Gripen pilots have learned that this makes it possible to delay using the AMRAAM's active seeker until it is too late for the target to respond.
But the use of the link goes beyond this, towards what the Swedish Air Force calls "samverkan," or close-cooperation. One example is the use of the Ericsson PS-05/A radar with TIDLS. An Ericsson paper compares its application, with identical sensors and precise knowledge of the location of both platforms, to human twins: "Communication is possible without explaining everything."
"Radar-samverkan," the Ericsson paper suggests, equips the formation with a super-radar of extraordinary capabilities. The PS-05/A can operate in passive mode, as a sensitive receiver with high directional accuracy (due to its large antenna). Two PS-05/As can exchange information by datalink and locate the target by triangulation. The target's signals will often identify it as well.
The datalink results in better tracking. Usually, three plots (echoes) are needed to track a target in track-while-scan mode. The datalink allows the radars to share plots, not just tracks, so even if none of the aircraft in a formation gets enough plots on its own to track the target, they may do so collectively.
Each radar plot includes Doppler velocity, which provides the individual aircraft with range-rate data. However, this data on its own does not yield the velocity of the target. Using the TIDLS, two fighters can take simultaneous range-rate readings and thereby determine the target's track instantly, reducing the need for radar transmission.
In ECM applications, one fighter can search, while the wingman simultaneously focuses jamming on the same target, using the radar. This makes it very difficult for the target to intercept or jam the radar that is tracking him. Another anti-jamming technique is for all four radars to illuminate the same target simultaneously at different frequencies.'”
Our Swedish Data-link updates every second (or faster
, as compared to Link16 (every twelfth second) This makes it possible for us to fly 'radar silent' and even shoot its missiles from it without any own radar. And the data-link is able to steer you in, in every detail (close control) through its data commands. Which means that Gripen will be very operational even with its radio totally jammed. The NATO variant Link16 can, if I'm correct, open up to four(?) 'timeslots/channels' and if you place them correctly in time, give you a update every third second. (But we can also do that kind of stuff and as our systems each update every second by themselves (or faster
you might wonder how much info we would be able to transmit that 'NATO' way opening new 'timeslots'. Not that I know of course, just guessing here
Our system have the possibility to use AWACS, and satellites, and 'peer2peer'. It seems to me that Link16 first handedly is a 'centralized' system, now also trying to in cooperate some of the Swedish 'ideas'. As for what is best in a battle situation? I prefer the one with the most options myself, and that's not Link16. And it's not only Gripen using our system, it's used in all types of military vehicles, that's why it is so redundant. And that's why we still will have a 3-D sphere of information, even when all AWACS is down. We use all available radar, and their data links too. But remember, ours system is 'peer to peer', just like the Internet, built for durability.
“Link 16 (also known as TADIL J in the US) has been designed to optimize the use of the MIDS/JTIDS architecture. MIDS is a major U.S.-led international programme in which Link 16 compatible data communications terminals are being developed. Link 16 is defined as the designation for Joint Tactical Information Data System (JTIDS) waveform and protocol compatible radios that transmit and receive data messages in the TADIL-J message catalog. Gripen and Saab 340 with Erieye.
Link 16 has been developed to meet the information exchange requirements of all tactical units, supporting the exchange of surveillance data, EW data, mission tasking, weapons assignments and control data. Link 16 is the NATO-standard tactical datalink that is being adopted by more and more users, on more and more platforms, to support coalition operations. In addition to the Swedish data link, Link 16 is now an option in Gripens onboard datalink capabilities. This further enhances Gripen’s interoperability and gives users an even wider choice of networked systems to meet their national and international needs.”
Well, in a way, maybe, but for a prise. We lost some sweet capabilities to that adaption, but hey, look at the bright side, we gained some weight
“In BVR combat, where information and situational awareness are key to success, a datalink system gives the user unrivaled battlespace awareness. The advantages of datalink systems are well recognized elsewhere and include the JTIDS used by US armed forces and Britain's RAF, and NATO's Link 16. However, these other systems are fitted only to a few aircraft and are generally command-driven systems used to guide other aircraft. They do not allow a free flow of information between platforms and are limited in the type of data they can handle. Furthermore, compared to the CDL39 their basic data exchange rates are painfully slow. Types like the Super Hornet and Eurofighter Typhoon will be the first operational aircraft outside Sweden to have datalink capability that comes anywhere matching that of the Gripen.
The CDL39 is fully integrated with Sweden's new tactical Radio System(TARAS) - a secure radio network for JAS39 Gripen and JA37D Viggen fighters, S100B Argus AEW&C platforms, S102B Korpen SIGINT aircraft and ground-based Stridslednings Central, Command and Control Center (StriC) units. The FMV is currently working to make CDL39 capable of communicating with JTIDS for international Gripen operations. Up to four aircraft can be actively transmitting on the datalink at any one time and an infinite number can be receiving(passive).
As its most basic function the CDL39 can transmitt radar/sensor pictures and aircraft/weaponry status data anywhere on the TARAS network. To send data on the link all the pilot has to do is select the appropriate radio channel/which will be preset by the mission planning system) and transmit. extensive testing has shown the system to be unjammable.
The Gripen's datalink offers enormous flexibility. For example, in the air to surface role one aircraft "package" can attack a target, obtain a radar picture of the the target area and realy it to the cockpits of the next wave of attackers. Those aircraft would receive an accurate image of the target area, allowing them to know which targets have already been attacked. Furthermore this information can be relayed back to the StriC for decisions based on the actual situation.
In the air to air role it is possible for one Gripen to transmit its radar picture of an airborn target to the radar screen of another aircraft. The second aircraft can the leave its radar switched off, approach the target and engage it without ever betraying its precense. Weapons launch even can be guided from the first aircrafts radar. Using AEW&C radar, a much larger airpicture can be datalinked to a formation of Gripens, to increase their combat reach.
The Gripen/datalink combination offers formidable capabilities. The airforce has run air defence exercises deplying just six Gripens to defend half the country. Using the CDL39, three pairs of aircraft flying CAP are able to monitor Sweden's entire east coast, from the northern edge of the island of Gotland in the Baltic to Ronneby Air Base and beyond, to the souther tip of the country. Each Gripen pilot can be confident that everybody knows where everyone else is at all times, what they are seeing and what they are doing.
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