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F-35 avionics system

This is a discussion on F-35 avionics system within the Air Force & Aviation forum, part of the Global Defense & Military category; Originally Posted by r3mu511 I'll admit though my tech interest is less on LO as a whole, and more on ...


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Old August 16th, 2016   #16
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I'll admit though my tech interest is less on LO as a whole, and more on just RF scattering.
rf scattering is only part of the sig management set though....
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Old August 16th, 2016   #17
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rf scattering is only part of the sig management set though....
Yup, it's a limited scope for me - just a personal preference of what I like to study
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Old August 16th, 2016   #18
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Do you happen to have any more info on this? Maybe the name of the person who worked on this software for Northrop? I'ld really like to read up on more papers which were used in the past by other manufacturers similar to the 1970's relationship of Lockheed to Overholser/Ufimstev's work.
I'll have a look for it, & see if I can find the place I read about it again. IIRC it named the software, but I don't recall any mention of whose work it was.
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Old August 16th, 2016   #19
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I'll have a look for it, & see if I can find the place I read about it again. IIRC it named the software, but I don't recall any mention of whose work it was.
Ok thanks, much appreciated.
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Old August 17th, 2016   #20
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Was reading up on diffraction (and hunting for some info on Northrop's work) and came across the textbook "Fundamentals of the Physical Theory of Diffraction" by Ufimtsev, which had a foreword by Kenneth Mitzner (who worked on the B-2 for Northrop), in which he said (in the quote "PTD" refers to Ufimtsev's physical theory of diffraction):

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At Northrop, where I worked on the B-2 project, we were so enthusiastic about PTD that a co-worker and I sometimes broke into choruses of “Go, Ufimtsev” to the tune of "On,Wisconsin." At both Lockheed and Northrop we referred to PTD as "industrial-strength" diffraction theory...
So it seems at least for the B-2, Northrop shifted to using Ufimtsev's methods to numerically approximate RF scattering.

There are alternative methods for numerical approximation of RF diffraction which like PTD account for the contributions from edges/discontinuities, but have more limitations than PTD. One method was devised by Joseph Keller around the early 1950s, called the "geometrical theory of diffraction" (GTD, and it's extension the "method of equivalent currents", MEC), but I haven't found any traces of a possible link of Keller's work to Northrop during their pre-B-2 development (ie. XST project).

For the timeline in question (1950s-1970s) published numerical solutions to RF scattering (which included edge/discontinuity effects) were either PTD or GTD based, so I'm really curious as to what Northrop might have been using for their pre-B-2 XST development.
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Old August 17th, 2016   #21
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For the timeline in question (1950s-1970s) published numerical solutions to RF scattering (which included edge/discontinuity effects) were either PTD or GTD based, so I'm really curious as to what Northrop might have been using for their pre-B-2 XST development.
you also have to factor in the unmanned developments - and a lot of the RCS minimisation discoveries were also accidental side effects.

in the 50/60's they literally were using chicken wire and tar for blending and signal absorption
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Old August 17th, 2016   #22
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^yup, definitely agree they had empirical, accidental, or even trial-and-error based techniques... but I have to admit I am more interested in what could be Northrop's historical numerical/theory-based method of RF scattering approximation used in their pre-B-2 project (ie. what was the computational model of the software @swerve mentioned which Northrop were using at the time)...
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Old August 17th, 2016   #23
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somewhere, in some place on this planet, you just know that someone will think that this has happened..... (it was on google, so had to be true)

F-35 Delayed After Fourth Prototype Becomes Self-Aware And Has To Be Destroyed
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Old August 18th, 2016   #24
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somewhere, in some place on this planet, you just know that someone will think that this has happened..... (it was on google, so had to be true)

F-35 Delayed After Fourth Prototype Becomes Self-Aware And Has To Be Destroyed
People dont seem to double check fact at all so i think a very large number of people will actually believe that like they did believe the moon conspiracy theory
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Old July 5th, 2017   #25
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New article up today
Infrared sensor

Apparently, the blog is written by GarryA from Keypublishing
Aircraft 101: Radars, stealth, ECM and more!!
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Old July 5th, 2017   #26
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New article up today
Infrared sensor

Apparently, the blog is written by GarryA from Keypublishing
Aircraft 101: Radars, stealth, ECM and more!!
I had a quick glance at the first link, very interesting for the scientifically inclined. These will require a significant time investment. I have tagged them for a winter read.
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Old July 8th, 2017   #27
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Interesting reference to the British Canberra. In the early '50s being able to fly a bomber at 70,000' was about as LO as you can get, tho that was a record altitude and not typical. But I get fuzzy thinking about cause I saw one of USAFs last operating ones on the tarmac, set for recce, in '79 during the Iran hostage grab.

Looking at its form ir seems that the English designers had radar LO in mind when they built it. Is that true?


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look at the first 4 american manned versions of stealth aircraft - all take unique approaches to the platform design - all use different approaches and design philosophies

ditto for every unmanned development

A brief history of LO
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Old July 8th, 2017   #28
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Looking at its form ir seems that the English designers had radar LO in mind when they built it. Is that true?
the key phrase is LO.

in the late 40's through to late 50's it was about penetrating russian air space and being able to defeat their defensive systems. LO as a construct was not on the lexicon

the US tried doing this initially with aircraft such as the B45 but they were sitting ducks. The Canberras were able to penetrate high and fast and the russians had nothing that could intercept them at either the platform or weapons system level

in fact its easy to establish that the success of the canberra drove russian missile developments from the mid 50's on

the USAF actually ran rebadged RAF canberras for a number of years until they started delivering their own modified licensed versions
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Old July 8th, 2017   #29
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Thanks for the reply. That B57 was at an air base in S/E Turkey in Nov. 1979 right after our Hostages were taken at that embassy. Rigged for recce. I always wondered why we used that plane. It was the only time Ive ever seen one.

Looking at its Lines it always seemed to have fewer sharp angles, except of course for the tail. And since the Brits were on the cutting edge of radar at the time I always thought "maybe" it was designed to bounce less radar then other era war planes. Most of all because of its recce mission profile, along with that of a bomber.


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the key phrase is LO.

in the late 40's through to late 50's it was about penetrating russian air space and being able to defeat their defensive systems. LO as a construct was not on the lexicon

the US tried doing this initially with aircraft such as the B45 but they were sitting ducks. The Canberras were able to penetrate high and fast and the russians had nothing that could intercept them at either the platform or weapons system level

in fact its easy to establish that the success of the canberra drove russian missile developments from the mid 50's on

the USAF actually ran rebadged RAF canberras for a number of years until they started delivering their own modified licensed versions
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