F-35 Program Docs

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Dragon029

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Unread post28 Jun 2018, 06:09

Keep in mind that the numbers are going to be more around 1000x1000 pixels per sensor, each covering 95-120 degrees, meaning at 10nmi a pixel covers a max of roughly 127x127 feet.
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Unread post28 Jun 2018, 15:07

I am assuming the total pixel count goes up by 5x, not the count in each row/column. This would be more like 447x447.

If we use your numbers however, then each one EODAS I pixel is divided into 14 EODAS II pixels.

If I go back to 200x200 and say 120deg FOV (I suppose they do overlap) we are down to 0.6 degrees per pixel, which at 10nm is a 637x637ft block of space. Going to 447x447 for the sensor is 0.27 degrees per pixel, which at 10nm is a 286x286ft block of space. That is 5x the resolution. At 20nm the 447x447px sensor yields 573x573ft, still somewhat better than the EODAS I at 10nm. Seems to follow a square root for range relative to resolution, so 5x resolution is a 2.23x range.

Does anyone even have a clue what the current resolution is? A Megapixel count or anything?
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Unread post28 Jun 2018, 17:03

When I say 1000x1000, I'm talking about the current DAS; in the "Of DAS, EOTS etc.." thread it was discussed a couple of years ago how the DAS sensors were almost certainly using one of two FPAs from L3, one being a 1k (1000x1000) FPA (this one is most likely imo), the other being a 4k (2000x2000) FPA. Even if it were neither, you certainly wouldn't get the DAS imagery we've seen from a 200x200 sensor covering 90+ degrees.

A 5x resolution sensor would therefore be approximately 2240x2240.
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Unread post28 Jun 2018, 17:53

Thanks Dragon. 2kx2k would give a 64X64ft cell at 10nm. A planview of an Eagle would nearly fill that and the exhaust plume, even in Mil, would trail into several more cells. 5 times that resolution would give a 29x29ft cell at 10nm. Even a head-on Viper will fill up a large portion of that. Assuming 120 degree FOV. This jives more with claimed detection ranges, but not the 20/40 display to the Helmet. Granted, I was assuming the Helmet display was EO/DAS resolution limited and that may be a very incorrect assumption. The more I think about it the less correct that assumption sounds.
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Unread post29 Jun 2018, 08:53

Dragon029 wrote:When I say 1000x1000, I'm talking about the current DAS; in the "Of DAS, EOTS etc.." thread it was discussed a couple of years ago how the DAS sensors were almost certainly using one of two FPAs from L3, one being a 1k (1000x1000) FPA (this one is most likely imo), the other being a 4k (2000x2000) FPA. Even if it were neither, you certainly wouldn't get the DAS imagery we've seen from a 200x200 sensor covering 90+ degrees.

A 5x resolution sensor would therefore be approximately 2240x2240.


Correct. This L3 Cincinnati Electronics web page was source for that:
https://www2.l3t.com/ce/products/infrar ... format.htm

L3 Cincinnati Electronics is the industry leader in large-format MWIR with a decade of experience in providing IR technology for major programs such as the F/A-18 and F-35. In addition to our compact 1280 x 1024 and 2048 x 2048 pixel MWIR HD cameras, we are the only manufacturer with IR sensors of 16Mp (4096 x 4096 pixels) currently in use by U.S. assets in overseas combat zones.


That seems to imply that they used either the 1280x1024 or 2048x2048 detector in DAS. I think there was another statement by the company about manufacturing DAS detectors in factory that manufactures only those megapixel detectors. I think it's most likely that they used the lowest resolution 1.2 megapixel detector although I can't be sure. Incidentally almost all public DAS videos are recorded using 1280x720 resolution...

Five times the resolution is interesting statement as that does not directly fit any MWIR detector that I could find. Maybe that was not exact technical description but just general description about improved capabilties. Most likely new detector seems to be 2kx2k.
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Unread post29 Jun 2018, 17:51

I don't know how much an MWIR detector can be compared to a DSLR sensor, but my 10 year old Nikon D300 have a 13MP sensor, while my new D850 has a 45MP sensor. Both cameras represents the top amateur camera from Nikon at the time. That's 346% improvement over 10 years. An unedited picture comes out at 8256x5504 pixel dimensions at 300dpi resolution and 24bit depth.
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Unread post29 Jun 2018, 17:59

How well would the Nikon hold up to 9G. Or buffeting? Mil-Spec gear is, by necessity, more robust and trails the civilian market.
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Unread post29 Jun 2018, 19:21

sprstdlyscottsmn wrote:How well would the Nikon hold up to 9G. Or buffeting? Mil-Spec gear is, by necessity, more robust and trails the civilian market.


I doubt G or buffeting has much influence on the sensor itself, but rather how it is mounted. The extreme temperature differences an aircraft is exposed to is a different matter though. The rest of the Nikon would likely fail fast. However, that's not the point. What I'm trying to get across is that image sensors have improved a lot in 10 years, so if the current DAS is closing on 20 years, an improved version should get an impressive boost in performance.

I have personally seen testing of an electronic component, where it failed the Mil-Spec test, but passed for civilian purposes. It was a component to the precursor to the JSM, the Pingvin missile.
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Unread post29 Jun 2018, 19:28

Keep in mind that a DSLR has many moving parts while the EODAS has none as it's a fixed-focus sensor.
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Unread post29 Jun 2018, 23:51

The main reason (as far as I'm aware) that infrared sensors like the DAS have a lower resolution than your typical DSLR, etc, is simply because (similar to radar antennas), infrared light (MWIR specifically) is roughly 10x larger in wavelength than visible light (around 8-9x larger than green light).

And so, in order to have sufficient collection of infrared light, as well as sufficient resolution, you have to use larger individual focal plane arrays with larger photoreceptors (pixels), a bit like how going from X-band to VHF you need larger antennas to have sufficient gain and in turn, a much larger antenna array to have similar angular resolution.

And so to have larger resolutions, you either:

1. Make larger focal plane arrays (which isn't easy, because in electronics, chips are made from wafers; circles of either silicon, gallium arsenide, indium antimonide, etc that multiple sensors and processors, etc are made from; when it comes to making computer processors, not all of the wafer will be perfect, so some of the processors cut out of it won't work, and so having larger chips that take up more of a wafer is riskier / more expensive to have acceptable / profitable yields), or...

2. Decrease the size of the pixels and try to manage the decrease in gain with improvements in sensitivity through adjustments to the substrate material, or by using improved signal / image processing (like with new smartphones), or by increasing optics to bring in more light and focus it onto the same smaller chips (this solution has issues of its own like increased weight, size & fragility, increased potential to damage the sensor, etc).
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Unread post02 Jul 2018, 14:42

Here are links to all of the 2018 AIAA Aviation Forum F-35 technical papers that were released:

Program Overview Papers:

F-35 Program History – From JAST to IOC (AIAA 2018-3366)
https://arc.aiaa.org/doi/pdf/10.2514/6.2018-3366

F-35 Air Vehicle Configuration Development (AIAA 2018-3367)
https://arc.aiaa.org/doi/pdf/10.2514/6.2018-3367

F-35 Air Vehicle Technology Overview (AIAA 2018-3368)
https://arc.aiaa.org/doi/pdf/10.2514/6.2018-3368

F-35 Production – Advanced Manufacturing and the Digital Thread (AIAA 2018-3369)
https://arc.aiaa.org/doi/pdf/10.2514/6.2018-3369

F-35 Weapons Design Integration (AIAA 2018-3370)
https://arc.aiaa.org/doi/pdf/10.2514/6.2018-3370

F-35 System Development and Demonstration Flight Testing at Edwards Air Force Base and Naval Air Station Patuxent River (AIAA 2018-3371)
https://arc.aiaa.org/doi/pdf/10.2514/6.2018-3371


Air System Design papers:

F-35 Structural Design, Development, and Verification (AIAA 2018-3515)
https://arc.aiaa.org/doi/pdf/10.2514/6.2018-3515

F-35 Flight Control Law Design, Development and Verification (AIAA 2018-3516)
https://arc.aiaa.org/doi/pdf/10.2514/6.2018-3516

F-35 Propulsion System Integration, Development & Verification (AIAA 2018-3517)
https://arc.aiaa.org/doi/pdf/10.2514/6.2018-3517

F-35 Subsystems Design, Development & Verification (AIAA 2018-3518)
https://arc.aiaa.org/doi/pdf/10.2514/6.2018-3518

F-35 Mission Systems Design, Development & Verification (AIAA 2018-3519)
https://arc.aiaa.org/doi/pdf/10.2514/6.2018-3519

F-35 Information Fusion (AIAA 2018-3520)
https://arc.aiaa.org/doi/pdf/10.2514/6.2018-3520


Test and Evaluation papers:

F-35 Carrier Suitability Flight Testing (AIAA 2018-3678)
https://arc.aiaa.org/doi/pdf/10.2514/6.2018-3678
download/file.php?id=27706 [Courtesy of Spazsinbad]

F-35 Aerodynamic Performance Verification (AIAA 2018-3679)
https://arc.aiaa.org/doi/pdf/10.2514/6.2018-3679

F-35 Weapons Separation Test and Verification (AIAA 2018-3680)
https://arc.aiaa.org/doi/pdf/10.2514/6.2018-3680

F-35 STOVL Performance Requirements Verification (AIAA 2018-3681)
https://arc.aiaa.org/doi/pdf/10.2514/6.2018-3681

F-35 Climatic Chamber Testing & System Verification (AIAA 2018-3682)
https://arc.aiaa.org/doi/pdf/10.2514/6.2018-3682


A 6th Test and Evaluation technical paper was also meant to be released (for a total of 18) called "F-35 High Angle of Attack Flight Control Development and Flight Test Results", but this paper doesn't appear in the list of those released at the conference: https://arc.aiaa.org/doi/book/10.2514/MATIO18
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Unread post02 Jul 2018, 15:38

Good job on that, thanks.

--Edit.. Joy, a paywall :bang:

Those at a college (or local library via OpenAthens login) should have access, hint, hint :roll:
Last edited by SpudmanWP on 02 Jul 2018, 20:18, edited 1 time in total.
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Unread post02 Jul 2018, 17:23

PODcast at AvWeak by those who bin there talking about it - this one all about the F-35 - other things in later podcast:
Podcast: Hidden Gems at AIAA Aviation 2018
29 Jun 2018 Guy Norris and Graham Warwick

"Aviation Week’s Guy Norris and Graham Warwick have been in Atlanta, Georgia, for the American Institute of Aeronautics and Astronautics’ Aviation 2018 conference. They talk about insights from the many panels and presentations and some hidden gems in the exhibition hall."

Source: http://aviationweek.com/future-aerospac ... ation-2018
A4G Skyhawk: www.faaaa.asn.au/spazsinbad-a4g/ & www.youtube.com/channel/UCwqC_s6gcCVvG7NOge3qfAQ/videos?view_as=subscriber
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Unread post02 Jul 2018, 20:17

I just found out a FREE way to get the docs.

Use the OpenAthens login and search for your local library if you have a library card. OpenAthens also services many higher education colleges & universities.
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Dragon029

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Unread post03 Jul 2018, 00:03

I've found another means of downloading them all; I'll clean them up and upload them here later today.
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