How does TIDLS(Gripen) and TRAGEDAC(Rafale) compare to MADL?

Military aircraft - Post cold war aircraft, including for example B-2, Gripen, F-18E/F Super Hornet, Rafale, and Typhoon.
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hornetfinn

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Unread post16 Jan 2018, 14:24

I have not found any info about MADL data rate, but Common Data Link (CDL) supports up to 274 Mbps speeds (other speeds being 10.71, 44.7 and 137 Mbps). It's uses quite similar frequency band to MADL. Like nutshell noted, MADL might well be able to reach those speeds depending on conditions.
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monkeypilot

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Unread post17 Jan 2018, 18:10

Probably yes.
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loke

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Unread post17 Jan 2018, 22:30

herciv wrote:About CONTACT ESSOR and SDR
https://www.defenseindustrydaily.com/Ma ... ram-07440/


With the advent of the F4 Standard, the
Rafale will be equipped with the new
Thales Contact software radios that
will be widely fielded across the French
Armed Forces in the next couple of
years. These new-generation radios
will remain fully compatible with legacy
radio waves and should be tested
on the Rafale as early as 2020.
The Rafale will also be fitted with a
new point-to-point, directional, discreet,
high-speed fighter data link to be used
exclusively for communications and data
exchange within a Rafale patrol. This will
use a new three-dimensional waveform
(FO3D, or Forme d’Onde 3 Dimensions)
generated by digital signal processing
using dedicated antennas for the required
bandwidths and the expected data flow.
This new fighter data link will supplement
– and not replace – the current Link 16.
Accordingly, the Rafale’s core avionics
system will have to be modified to
accommodate the two data link systems
that will operate alongside each other
(although they will not be linked).
The architecture of the internal network
will have to be modified for it to become
even more resistant to cyber attack. The
CAPOEIRA (Connectivité Améliorée Pour
les Evolutions du Rafale, or improved
connectivity for the Rafale’s future variants)
research programme has recently been
launched to help determine what sort of
architecture will be required for a future,
totally secure navigation and attack system.


From: download/file.php?id=25484

Will the new directional link planned for Rafale F4 be according to the ESSOR standard? Or something else?
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monkeypilot

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Unread post17 Jan 2018, 22:41

Essor's IOC was last spring.
There is a wids misunderstanding with FO3D
FO3D was the word used by the DGA engineer at PAS17, but he meant FO (waveform) FOR 3D. Experiements starting end 2018. (ground and marine waveforms are already being qualified)
ESSOR is a library of waveforms in fact.
Contact is similar to JTRS i think.

It is quite mysterious Loke. Would love to know.
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aprichelieu

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Unread post18 Jan 2018, 20:50

hornetfinn wrote:TIDLS is very similar to Link 16 in many ways, although it's more specialized because it was designed just for Swedish Air Force needs. Technologically it's very similar to Link 16 system with omnidirectional antennas and transmitting using TDMA network system using UHF/L-band. Just look at here:
http://flygteknik.mcistockholm.se/filer ... lstrom.pdf

It's in Swedish, but can be easily translated.

AFAIK, TRAGEDAC is not a data link system at all, but rather software improvement for sensor fusion and data transmission. From what I've heard, it still uses Link 16 to transmit and receive data, but TRAGEDAC improves how data is fused together. AFAIK, it also allows transmitting data from SPECTRA and FSO to other Rafales and combine the data with radar tracks.

MADL is totally different as it uses directional antennas and much higher frequency than TIDLS or Link 16. It thus has superior stealth (narrow beams), throughput (higher frequency) and lower latency (direct point-to-point). Of course the downside is that it's much more difficult to implement on fighter aircraft.


Anyone got any information on the high speed link allowing video transmission that is mentioned in the presentation.
(Will anyone write a Youtube App for Gripen E, LOL?)
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citanon

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Unread post20 Mar 2018, 09:42

So, for once I actually found out something educational and interesting from talking with people over at BF4C. I know. Shocking, but a guy named Axel dug up some really interesting information establishing the exact capabilities of the broad band AESA ECM antenna on the Gripen E/F's new Araxis EW suite.

The questions we were discussing were the exact capabilities of the updated "directional" TIDLS in the Gripen E/F, and the prospective communications capabilities that could be extracted from the broad band AESA ECM antenna on the new Araxis EW suite should a data link capability be added to it.

My conclusions are:

1: the updated TIDLS is a directional UHF system utilizing a new phased array UHF antenna.
2: should Ku band communications be eventually added using Araxis antenna, the best achievable beam width would be very similar to the beam width achieved on the MADL phased array.

Too lazy to re-summarize everything so I will just quote my disqus post:

http://disq.us/p/1r1dexk

Gripen E's data link mystery: solved

We've been debating what type of data link the Gripen E will have. Is it broadcasting? Is it directional? Is it a tight beam system like F35's MADL?

This SAAB slide deck from Farnborough 2014 seems to have the answer:

https://www.slideshare.net/...

The Gripen E will have a "smart directional communications". That sounds like it's not an area broad casting system and not a tight beam one but a directional system to manage signature and improve jam resistance. Makes sense for Gripen's signature management requirements and operational needs.

Not quite as hard to detect as MADL but still not broadcasting everywhere and difficult to jam.

UPDATE: Since we've identified the location of the Gripen's UHF antenna and with Axel's find of a paper with the exact dimensions of Gripen's AESA ecm array:

http://ieeexplore.ieee.org/...
https://saabgroup.com/media...

we can actually do a basic estimate the beam width capabilities of the UHF antenna, the Ku band antenna and compare it with the MADL array on the F35. This is because there is a simple relationship between antenna size, wavelength and beamwidth:

http://www.phys.hawaii.edu/...

BWin radians ~ lambda/L where lambda is the wavelength and L is the length of the antenna.

The Gripen's tail fin UHF antenna has 40 cm total height. Assuming useable height of 35 cm, the UHF phased array's theoretical beam width is ~45 degrees at the traditional legacy TIDLS / Link 16 frequencies near 1 GHz. If pushed to 3 GHz the best theoretical performance is ~ 15 degrees.

The Gripen's broadband AESA ECM antenna is 16 cm by 9 cm. SAAB patents show schemes using different antenna areas for transmit and receive to cut down on noise interference. Assuming for simplicity that they use a 9 cm by 9 cm area in the Ku band, that gives beam width performance of ~11 degrees at 18 ghz and 16 degrees at 12 GHz.

After carefully examining F35 photos, the MADL array is a hexagon with vertex to vertex width of ~9.5 cm. This gives theoretical beam width performance very close to the Gripen's wing tip antenna pods:

10 degrees at 18 GHz and 15 degrees at 12 GHz.

So we see that the UHF system is actually sized so that its beam width ranges from somewhat directional (45 degrees) to just starting to overlap with the low end beam width of a prospective Ku band beam forming antenna (~15 degrees).

For the high frequency antenna arrays, both the Gripen's AESA ECM antenna and the MADL antenna on the F35 have very similar dimensions. They are both designed to give 10 to 15 degree beams in the Ku band.

Although currently we can identify no concrete information from SAAB indicating that a Ku band narrow beam data link has been implemented, it would seem that were one to be added as a software update in a future block, the performance could be quite similar to MADL, at least in terms of beam width.

We can also surmise that current military thinking has settled on a consensus of 10 degrees to 15 degree beams as optimal for advanced low probability of intercept, high bandwidth, narrow beam data links.
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hornetfinn

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Unread post20 Mar 2018, 12:46

Using semi-directional (or sector) antenna and changing nothing else would seem most logical next step for TIDLS. That would keep costs down while giving better LPI/LPD characteristics and jam resistance. It could also increase effective range due to having higher gain. There have been similar systems for Link 16 and Link 22 like this:
https://www.army-technology.com/contrac ... -antennas/

I really doubt they are doing anything else with TIDLS as it would quickly become easier and cheaper to design a totally new data link system. Changing wavelength alone would mean very extensive changes to the system. Going to a totally new high frequency directional data link (like MADL) would be best bet, but it's not easy nor cheap to design and retrofit. I really doubt Saab and Sweden could do it. Even USA is using all kinds of workaround systems to connect legacy jets and 5th gen jets.
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monkeypilot

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Unread post20 Mar 2018, 17:31

It is already quite complicated to manage interferences between several apertures...
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citanon

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Unread post20 Mar 2018, 18:08

SAAB has been making a lot of noise about their new directional beamed TIDLS and apparently one of the significant physical changes is turning the tip of the tail fin into the new UHF antenna housing. (If I read their diagram right).

With the shape of the new housing I think it makes sense to have some sort of a uhf phased array in there. If they had one in the tail it would give them about a 45 degree solid angle beam at 1 ghz (ie no changes from the current operating frequency). They could do either source or receptor beam forming or both which would be very jam resistant.

https://en.m.wikipedia.org/wiki/Beamforming

UHF phased arrays are common and cheap. Your average consumer broadcast TV receiver antenna is a UHF phased array.

Since it's a bigbdesign feature for them maybe it's not too expensive to add.

That array in the research paper is 100% what is in the front of their new ECM pod. There is even a cutaway mockup from an air ahow. The research paper says it covers the entire Ku band and could be used for communications. No indication it's currently being used as such.

Rafael is apparently going to a full MALD style system for intra flight data link in the F4.2 stanfard according to this July 2017 article, page 7.

http://disq.us/url?url=http%3A%2F%2Fwww ... id=2394125
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Unread post25 Jul 2020, 00:12

Not so much about comparison with MADL, but some about TIDLS and L16 on the Czech Gripens, incl difference between them. Also a lot about the history of digital link systems in the Swedish airforce: https://www.secretprojects.co.uk/thread ... cle.33880/
I think description of the first system för J35 Draken in the beginning of the 60:s was interesting, were the individual aircrafts received position and heading of the enemy from ground radars, as well as commands about which action to perform. Yes, standard since many years, but I had not thought about how long that had been around for fighters.

The Gripen datalink has two basic elements - air-to-ground and air-to-air connections with other aircraft. TIDLS can connect up to four aircraft in real time in both directions (some sources even state 8), the number of recipients of data information is not limited. The range is about 500 km and is highly resistant to interference, transmitted in short time intervals. Each of the four participants uses 25% of their transmission time. Data is transmitted via pre-programmed broadcast channels. The Swedish manufacturer claims that the only way to disrupt the data connection is to place an active jammer directly between the two communicating aircraft.
TIDLS basic modes include the ability to display the position, direction, altitude and speed of all four aircraft in formation, including basic information such as fuel status, weapons, countermeasures, and even the cursor position on the multifunction display to allow pilots to highlight important targets for other aircraft. TIDLS differs in part from a similar alliance system, the Link 16. It provides connections to fewer users over shorter distances, but connects them more closely together, exchanges much more data, and works in near real time. The Swedish datalink is updated every second compared to Link16, which is updated every twelve seconds. TIDLS allows up to four aircraft to be connected in both directions over a distance of 500 km and at the same time allows access to data from the SAAB 340 Erieye early warning aircraft
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