Saudi F-15 shot down over Yemen - Page 27 - ED Forums
 


Notices

Reply
 
Thread Tools Display Modes
Old 02-20-2018, 06:16 AM   #261
Mfezi
Junior Member
 
Join Date: Nov 2017
Posts: 9
Reputation power: 0
Mfezi is on a distinguished road
Default

Quote:
Originally Posted by Emu View Post
What I'm trying to say is simple. The maximum amount of heat that can possibly be generated by a kinetic-only strike, is limited by the kinetic energy, which is far lower than the energy in the warhead, hence it can't produce the same sized flash in IR or visible band.
Emu, the amount of heat produced does not determine the size of the flash on FLIR. It determines the intensity. In the video from the original post of this thread, the FLIR is set too sensitive. It is very obvious: In the first 20 seconds, the F-15 is completely white and you can clearly see the engine exhaust before afterburner is activated. This is in stark contrast to most infrared videos that I have of missile tests, where the target is a dark grey prior to missile impact. Some FLIR systems will auto-adjust the temperature range, but in this case the aircraft is still bright white in the section of video following the impact, which tells us there was no adjustment over the span of the video.

The result of this overexposed imaging is that you cannot measure the relative intensities anymore. White is white: The heat generated by the aerodynamic friction on the airframe only is enough to saturate it (first 20 seconds), making the airframe appear white in the image. The afterburner saturates it to white. The flares saturate it to white. The impact saturates it to white. The relative size of each of these contributors simply signifies the extent of the heated gas surrounding the source. The amount of heat generated determines the intensity, but that you cannot measure anymore on this video because it is saturated.
Mfezi is offline   Reply With Quote
Old 02-20-2018, 02:18 PM   #262
Emu
Member
 
Join Date: May 2014
Posts: 905
Reputation power: 9
Emu is just really niceEmu is just really niceEmu is just really niceEmu is just really niceEmu is just really niceEmu is just really niceEmu is just really niceEmu is just really niceEmu is just really niceEmu is just really nice
Default

Quote:
Originally Posted by Mfezi View Post
Emu, the amount of heat produced does not determine the size of the flash on FLIR. It determines the intensity. In the video from the original post of this thread, the FLIR is set too sensitive. It is very obvious: In the first 20 seconds, the F-15 is completely white and you can clearly see the engine exhaust before afterburner is activated. This is in stark contrast to most infrared videos that I have of missile tests, where the target is a dark grey prior to missile impact. Some FLIR systems will auto-adjust the temperature range, but in this case the aircraft is still bright white in the section of video following the impact, which tells us there was no adjustment over the span of the video.

The result of this overexposed imaging is that you cannot measure the relative intensities anymore. White is white: The heat generated by the aerodynamic friction on the airframe only is enough to saturate it (first 20 seconds), making the airframe appear white in the image. The afterburner saturates it to white. The flares saturate it to white. The impact saturates it to white. The relative size of each of these contributors simply signifies the extent of the heated gas surrounding the source. The amount of heat generated determines the intensity, but that you cannot measure anymore on this video because it is saturated.
You can clearly see the engine exhaust before afterburner activation on any function FLIR. The size of the flash is very much determined by the energy. The size of nuclear explosion could even be accurately estimated by the flash duration.
Emu is offline   Reply With Quote
Old 02-20-2018, 02:49 PM   #263
Emu
Member
 
Join Date: May 2014
Posts: 905
Reputation power: 9
Emu is just really niceEmu is just really niceEmu is just really niceEmu is just really niceEmu is just really niceEmu is just really niceEmu is just really niceEmu is just really niceEmu is just really niceEmu is just really nice
Default

Quote:
Originally Posted by kolga View Post
What i am saying is since we don't know when it was launched we can't say how far anything has gone. But seriously are you still going to be bringing up MANPADS? No one actually believe it to be the most likely.



Yeah, i am not saying that any time a missile hits something it breaks up, just that in this specific incident it looks like it did. Just as in that incident it didn't.



I did and i didn't come up with anything other than the video that proves the motor can explode.



The way they are traveling at intercept does not always indicate exact launch aspect.



Have you ever been in a dark room and there is another person, I don;t know about you but I can't see them.



Yes, i agree, as long as all the parameters are identical.



???

I was talking about the blast not bleeding.



Ok, so after looking at the video again, It looks like the flash goes from 0 to its biggest in one frame so assuming 24FPS:

644,077,500/24=26,836,562.5

So in the lead wall no sound scenario you have 110% of the energy and then if we assume in real life 0.2 of the KE is converted to heat we get 22% plus the rocket motor burning off which makes a large flash perfectly possible.

So is what your trying to say that if there was an explosion of 90% of the energy of afterburners we wouldn't see it at all? To me that is preposterous.



Yep, i am not arguing MANPADS.



How do you know it was launched before the burners? It seems more likely for him to forget to pull out of burner than lighting them with a heat seeking missile inbound.



It shows a blast the same size, not a glowing flash.



There is no evidence of a third flare other than the Dutch journalist. Watch it again frame by frame.



?????????

My point is a rocket motor can and will explode when it hits an aircraft, something you have vehemently denied.



I think its pretty clear, when the glow brightly.
I believe several people actually do think it's most likely and it seems unlikely that a jet would ignite afterburners mid-flight and start popping flares for no reason, so this gives us and indication of the launch time.

It broke up because it exploded.

What video, you can't even be sure that is with an inert warhead.

If the target is travelling in roughly one direction, it very much does, as is the case here.

Try setting them on fire and you can see them quite easily. We are talking about a huge flash larger than afterburner here, that would take enough energy to produce effects visible in the visible band. Allowing for incomplete conversion of energy, it would take a 100+kg object doing Mach 10 on impact to produce a flash similar to F-15E afterburners.

They largely are and I think you know that.

The Hellfire blast on the zoomed out view is roughly the same size in FLIR as the one in the video, even with the addition of heated dust around it.

I think if it only last 1 frame I would not have been able to use YT pause to capture it as an image. It peaks quickly, which is again indicative of a warhead blast not a rocket failure but you can see that debris continues on after the strike still glowing larger than the afterburners because of the heat produced by the blast.

I keep mentioning it because some people out there believe it still to be a possibility, which it isn't.

He puts the burners on during the video. If he's just flying about with no threat, there's no much reason to do that.

The only difference is that in an A2A intercept everything is moving very fast as it explodes, whereas the ground stops an A2G missile, so the explosion happens in one place. Watch the original video again. The blast doesn't stop and start just as the missile passes near the plane.

I believe there is evidence, it's very subtle due to the afterburner glow, but it's there.

Is it definitely an inert missile in that one though? I would call this a proxy burst not a hit too.



But you were claiming some glowed brighter than other, to me, in your video, some are in afterburner and some aren't. On afterburner, all show produce a similar IR signature relative to the plane's size, because all have similar lb/lbf.hr and similar TWR.
Emu is offline   Reply With Quote
Old 02-20-2018, 03:06 PM   #264
Coxy_99
Senior Member
 
Coxy_99's Avatar
 
Join Date: Mar 2015
Location: UK
Posts: 2,607
Reputation power: 30
Coxy_99 is a name known to allCoxy_99 is a name known to allCoxy_99 is a name known to allCoxy_99 is a name known to allCoxy_99 is a name known to allCoxy_99 is a name known to allCoxy_99 is a name known to allCoxy_99 is a name known to allCoxy_99 is a name known to allCoxy_99 is a name known to allCoxy_99 is a name known to all
Default

A. UFO shot it down
B. Fake news
__________________
My rig psu corsair 850W, ASUS maximus hero iiiv, corsair H100i, I7 -6700K @4.0, corsair Ddominator ddr4 32GB ram, Evga GTX 1080 founders edition, Hyper kingston ssd drive.

Follow me on twitch and youtube also: https://www.twitch.tv/coxy_99/profile https://www.youtube.com/channel/UCLi...qEF8-UGWhwXD5A

Coxy_99 is offline   Reply With Quote
Old 02-20-2018, 04:23 PM   #265
GGTharos
Veteran
 
GGTharos's Avatar
 
Join Date: Nov 2004
Posts: 29,259
Reputation power: 307
GGTharos has a brilliant futureGGTharos has a brilliant futureGGTharos has a brilliant futureGGTharos has a brilliant futureGGTharos has a brilliant futureGGTharos has a brilliant futureGGTharos has a brilliant futureGGTharos has a brilliant futureGGTharos has a brilliant futureGGTharos has a brilliant futureGGTharos has a brilliant future
Default

That is an instrumented AIM-9X, without a warhead. It has a telemetry package in there instead.

The flash you see is from a direct hit to the horizontal stabilizer.

Quote:
Originally Posted by Emu View Post
Is it definitely an inert missile in that one though? I would call this a proxy burst not a hit too.
__________________

Reminder: SAM = Speed Bump
I used to play flight sims like you, but then I took a slammer to the knee - Yoda
GGTharos is offline   Reply With Quote
Old 02-21-2018, 03:05 AM   #266
kolga
Member
 
kolga's Avatar
 
Join Date: Sep 2014
Location: Depends on where I am.
Posts: 404
Reputation power: 4
kolga is on a distinguished road
Default

Quote:
Originally Posted by Emu View Post
I believe several people actually do think it's most likely and it seems unlikely that a jet would ignite afterburners mid-flight and start popping flares for no reason, so this gives us and indication of the launch time.
Then argue with them, not me. Nothing suggests MANPADS, but my only point about it was its not impossible.

The flares were obviously popped after launch, but the burners are a lot less sure.

Quote:
It broke up because it exploded.
As in detonated? I already know you believe that.

Quote:
What video, you can't even be sure that is with an inert warhead.
The video you posted a picture from, And yes it is inert, you think a 9.36kg warhead blast is that small???

Quote:
If the target is travelling in roughly one direction, it very much does, as is the case here.
Yeah, it can point you in the right direction, but you can't be sure unless you know altitude, speed ect.

Quote:
Try setting them on fire and you can see them quite easily. We are talking about a huge flash larger than afterburner here, that would take enough energy to produce effects visible in the visible band. Allowing for incomplete conversion of energy, it would take a 100+kg object doing Mach 10 on impact to produce a flash similar to F-15E afterburners.
Which would also produce tons of invisible heat as well.

Quote:
They largely are and I think you know that.
Are you trying to accuse me of lying? I was just saying if you have two identical (other than one being live and one inert) missiles traveling the same speed hitting the same target will produce very different results.

Quote:
The Hellfire blast on the zoomed out view is roughly the same size in FLIR as the one in the video, even with the addition of heated dust around it.
My point is there is no glow in the hellfire videos, therefore it is not a direct comparison for blast size.

Quote:
I think if it only last 1 frame I would not have been able to use YT pause to capture it as an image. It peaks quickly, which is again indicative of a warhead blast not a rocket failure but you can see that debris continues on after the strike still glowing larger than the afterburners because of the heat produced by the blast.
Why?

Show me the rocket failures you keep telling me about, i can't find them.

Also, do you believe a flare has 70% of the energy of the afterburners? Because its 70% of the size in the video.

Quote:
I keep mentioning it because some people out there believe it still to be a possibility, which it isn't.
I haven't seen them, if they want to argue let them come.

Quote:
He puts the burners on during the video. If he's just flying about with no threat, there's no much reason to do that.
So there is never a reason to use afterburners unless there is an incoming missile?

Quote:
The only difference is that in an A2A intercept everything is moving very fast as it explodes, whereas the ground stops an A2G missile, so the explosion happens in one place. Watch the original video again. The blast doesn't stop and start just as the missile passes near the plane.
The blast happens and then the hot debris and gases continue.

Quote:
I believe there is evidence, it's very subtle due to the afterburner glow, but it's there.
By all means show us the evidence then.

See attached images, and interpolate missile position.

Quote:
Is it definitely an inert missile in that one though? I would call this a proxy burst not a hit too.

IMG
Whats a proxy burst? Yes, it is inert.

Quote:
But you were claiming some glowed brighter than other, to me, in your video, some are in afterburner and some aren't. On afterburner, all show produce a similar IR signature relative to the plane's size, because all have similar lb/lbf.hr and similar TWR.
Some are not for a while and then light them and glow brightly.
Attached Thumbnails
Click image for larger version

Name:	1.png
Views:	7
Size:	178.7 KB
ID:	179569   Click image for larger version

Name:	2.png
Views:	6
Size:	175.5 KB
ID:	179570   Click image for larger version

Name:	3.png
Views:	7
Size:	177.0 KB
ID:	179571  

__________________
If the helicopter pilot does not attempt to exit the hazardous reform
regime at its earliest manifestations, in a lack of power screw
falls into the mode of a vortex ring
.- DCS MI-8MTV2 manual translated from Russian
"Amidst the blue skies, A link from past to future. The sheltering wings of the protector..." - ACE COMBAT 4
"Blessed be the LORD my strength, which teacheth my hands to war, and my fingers to fight"-Psalm 144:1 KJV
i5-4430 at 3.00GHz, 8GB RAM, GTX 1060 FE, Windows 7 x64

Last edited by kolga; 02-21-2018 at 03:08 AM.
kolga is offline   Reply With Quote
Old 02-21-2018, 06:04 AM   #267
Mfezi
Junior Member
 
Join Date: Nov 2017
Posts: 9
Reputation power: 0
Mfezi is on a distinguished road
Default

Quote:
Originally Posted by Emu View Post
You can clearly see the engine exhaust before afterburner activation on any function FLIR.
Thank you, but my experience with FLIR and infrared sensors in general is not based on watching YouTube videos. As I wrote in that post, the glowing white surface of the aircraft itself is a very clear indication of the FLIR sensitivity range used in that particular video. The brightness of the exhaust emissions prior to afterburner activation, especially from that aspect, is another.

Quote:
Originally Posted by Emu View Post
The size of the flash is very much determined by the energy. The size of nuclear explosion could even be accurately estimated by the flash duration.
The first of these two statements is already addressed in my previous post, but briefly once again: IR sensors do not measure energy, kinetic or otherwise, but infrared radiation. Since thermal radiation is mostly emitted in the infrared band, it is a useful indication of temperature, although it does also get influenced by the relative emissivity of the various objects in an image. When processing an IR image for display, the user or designer of the system sets the upper and lower bands of the temperature range of interest. Anything above that upper limit appears completely washed out, regardless of how much hotter it is than the threshold temperature. In this instance, we already know that upper limit is quite low, since the entire surface of the aircraft glows white throughout the video. Anything with a higher temperature or, more accurately, anything emitting infrared radiation above that upper threshold, still appears white, no matter how much higher its level of infrared radiation is.

On your second point: No, this is not how the yield of a nuclear explosion is measured, even though I did note that you sneakily changed flash "size" to flash "duration". Your addition of the word "accurately" is quite ironic, since accurately estimating the yield of a nuclear explosion is notoriously difficult and all methods that are used suffer from a very high level of statistic uncertainty. In fact, this is not limited to nuclear explosions - the energy released in any explosion is usually quite difficult to calculate accurately. One of the methods used to estimate the yield of an atmospheric nuclear explosion is via a bhangmeter, but this sensor works in the visible light range and is specifically "tuned" to the characteristics of an atmospheric nuclear explosion (i.e. it works by assuming the explosion will follow the characteristic double pulse visible light emissions typical of atmospheric nuclear explosions). Before that, they used to measure X-ray emissions which usually comes out in a single pulse of which the intensity does correlate somewhat with the yield of the explosion. The other methods commonly used are things like neutron activity analysis, infrasound or blast size scaling (again measured in the visible light range or measured from the damage on the ground afterwards) or fallout analysis in cases of fission explosions. For underground explosions, they normally use seismographic analysis to estimate the yield of the explosion. What I have never heard of, is using either the size or the duration of the flash on a saturated infrared image to estimate yield "accurately". If you can cite a scientific paper that uses this method, I would be very interested to read it.
Mfezi is offline   Reply With Quote
Old 02-21-2018, 08:30 PM   #268
kolga
Member
 
kolga's Avatar
 
Join Date: Sep 2014
Location: Depends on where I am.
Posts: 404
Reputation power: 4
kolga is on a distinguished road
Default

Quote:
Originally Posted by Mfezi View Post
Thank you, but my experience with FLIR and infrared sensors in general is not based on watching YouTube videos. As I wrote in that post, the glowing white surface of the aircraft itself is a very clear indication of the FLIR sensitivity range used in that particular video. The brightness of the exhaust emissions prior to afterburner activation, especially from that aspect, is another.



The first of these two statements is already addressed in my previous post, but briefly once again: IR sensors do not measure energy, kinetic or otherwise, but infrared radiation. Since thermal radiation is mostly emitted in the infrared band, it is a useful indication of temperature, although it does also get influenced by the relative emissivity of the various objects in an image. When processing an IR image for display, the user or designer of the system sets the upper and lower bands of the temperature range of interest. Anything above that upper limit appears completely washed out, regardless of how much hotter it is than the threshold temperature. In this instance, we already know that upper limit is quite low, since the entire surface of the aircraft glows white throughout the video. Anything with a higher temperature or, more accurately, anything emitting infrared radiation above that upper threshold, still appears white, no matter how much higher its level of infrared radiation is.

On your second point: No, this is not how the yield of a nuclear explosion is measured, even though I did note that you sneakily changed flash "size" to flash "duration". Your addition of the word "accurately" is quite ironic, since accurately estimating the yield of a nuclear explosion is notoriously difficult and all methods that are used suffer from a very high level of statistic uncertainty. In fact, this is not limited to nuclear explosions - the energy released in any explosion is usually quite difficult to calculate accurately. One of the methods used to estimate the yield of an atmospheric nuclear explosion is via a bhangmeter, but this sensor works in the visible light range and is specifically "tuned" to the characteristics of an atmospheric nuclear explosion (i.e. it works by assuming the explosion will follow the characteristic double pulse visible light emissions typical of atmospheric nuclear explosions). Before that, they used to measure X-ray emissions which usually comes out in a single pulse of which the intensity does correlate somewhat with the yield of the explosion. The other methods commonly used are things like neutron activity analysis, infrasound or blast size scaling (again measured in the visible light range or measured from the damage on the ground afterwards) or fallout analysis in cases of fission explosions. For underground explosions, they normally use seismographic analysis to estimate the yield of the explosion. What I have never heard of, is using either the size or the duration of the flash on a saturated infrared image to estimate yield "accurately". If you can cite a scientific paper that uses this method, I would be very interested to read it.
Wow, that is a very interesting and informative post, thank you for sharing your expertise!
__________________
If the helicopter pilot does not attempt to exit the hazardous reform
regime at its earliest manifestations, in a lack of power screw
falls into the mode of a vortex ring
.- DCS MI-8MTV2 manual translated from Russian
"Amidst the blue skies, A link from past to future. The sheltering wings of the protector..." - ACE COMBAT 4
"Blessed be the LORD my strength, which teacheth my hands to war, and my fingers to fight"-Psalm 144:1 KJV
i5-4430 at 3.00GHz, 8GB RAM, GTX 1060 FE, Windows 7 x64
kolga is offline   Reply With Quote
Old 02-21-2018, 09:41 PM   #269
proletariat23
Member
 
Join Date: Feb 2017
Location: CA
Posts: 114
Reputation power: 0
proletariat23 is infamous around these partsproletariat23 is infamous around these partsproletariat23 is infamous around these parts
Default

it was a flir augmented sa2, the f-15 did not crash, it made it back to a friendly divert in a foreign country.the internet is full of misinformation and useless arguments based around that misinformation.
proletariat23 is offline   Reply With Quote
Old 02-22-2018, 01:33 AM   #270
kolga
Member
 
kolga's Avatar
 
Join Date: Sep 2014
Location: Depends on where I am.
Posts: 404
Reputation power: 4
kolga is on a distinguished road
Default

Quote:
Originally Posted by proletariat23 View Post
it was a flir augmented sa2, the f-15 did not crash, it made it back to a friendly divert in a foreign country.the internet is full of misinformation and useless arguments based around that misinformation.

Source?
__________________
If the helicopter pilot does not attempt to exit the hazardous reform
regime at its earliest manifestations, in a lack of power screw
falls into the mode of a vortex ring
.- DCS MI-8MTV2 manual translated from Russian
"Amidst the blue skies, A link from past to future. The sheltering wings of the protector..." - ACE COMBAT 4
"Blessed be the LORD my strength, which teacheth my hands to war, and my fingers to fight"-Psalm 144:1 KJV
i5-4430 at 3.00GHz, 8GB RAM, GTX 1060 FE, Windows 7 x64
kolga is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT. The time now is 04:54 AM. vBulletin Skin by ForumMonkeys. Powered by vBulletin®.
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.