13.03.2018
"GO FAST" Footage from Tom DeLonge's To The Stars Academy. Bird?
Just did another demonstration of the parallax motion illusion.
Source: https://www.youtube.com/watch?v=IRd1RY2PuvA
+++Again, the TTSA release has made the main-stream news. Here is an opinion by Christopher Mellon, published in the Washington Post, ignoring all research that has been done since December:
https://www.washingtonpost.com/outl...2c125c-22ee-11e8-94da-ebf9d112159c_story.html
Excerpt:
I'm open to suggestions, but this object does not appear to be moving at a great speed.
I plotted with red dots each location the flying entity appears in the two opening segments with minimal camera motion. These segments are run at half speed. To me, the paths look consistent with the slightly erratic path of a bird. There's also two points I note where the object seems to slow down, but it's all so blurred and grainy I can't be sure.
Notable is that its brightness often dims down to almost invisible. That would seem to be consistent with wing flaps, changing the surface area exposed to the lens. However, when the camera locks onto it later it does not seem to fade out. So there are some notable differences with the before- and after-locked object.
When that camera locks on in the rest of the footage you can’t detect any erratic motions or fading of its brightness. When the camera gets locked on, it looks more like a sphere-shaped object. But then IR only shows temperature, not necessarily mass shape. But really?! Putting any extraordinary belief into just another grainy pin-head sized UFO seems foolish. #3 underwhelms!
Last year WaPo said this (bold added):
So the three TTSA videos we've examined are the best of the best. Just wow! "intelligence officer Luis Elizondo quietly arranged to secure the release of three of the most unusual videos in the Pentagon’s secret vaults."Content from external source+++ I thought a balloon is more likely because a bird would appear warmer than the background. I thought that a balloon would be more likely than a bird because 12,000 ft seemed rather high for birds to be flying. I was rather surprised to learn that 12,000 ft isn't very high and well within the range of many migratory birds and birds of prey.
https://en.wikipedia.org/wiki/List_of_birds_by_flight_heights
Also, I wonder how the WSO detected it in the first place. Did it show up on radar or on FLIR in wide field of view?+++What value did you use for this? Subtracting out the camera's forward velocity+++ The WaPo article also said something that at least Leslie Kean and maybe Elizondo disputed: Last year WaPo said this (bold added):
So the three TTSA videos we've examined are the best of the best. Just wow! "intelligence officer Luis Elizondo quietly arranged to secure the release of three of the most unusual videos in the Pentagon’s secret vaults."Content from external source
It suggested that Elizondo tricked the Pentagon into releasing the videos, but Leslie Kean told Open Minds UFO Radio that the memo she read didn't have any false pretense, though it may have been a different memo. Elizondo may have said this as well, but I don't remember. The point is to take the WaPo reporting with a grain of salt. Elizondo, in an internal Pentagon memo requesting that the videos be cleared for public viewing, argued that the images could help educate pilots and improve aviation safety. But in interviews, he said his ultimate intention was to shed light on a little-known program Elizondo himself ran for seven years: a low-key Defense Department operation to collect and analyze reported UFO sightings.Content from external source
That said, it makes sense that Elizondo would want to release the most unusual videos, and it's almost funny how disappointing they were, like literally "It's a bird, it's a plane."
Edit: Elizondo did deny any false pretense in a recent interview. But he also said, "We got very clever at dual-using" like putting out requirements that could apply to studying ballistic missiles or "other objects."
+++@Agent K I agree that if these are three of the best videos, it is not very convincing. Nice work @igoddard The apparent change in can also be attributed to camera trajectory. Can you extract the raw data from thos plots? Also, if anyone can extract aircraft attitude from the artificial horizon, I can add that to the simulation above and solve for x, y, z and v of the object.
I added the camera position and found an error in the previous plot. Here is the new plot in absolute position from the initial range solution.
@Mick West , I used 258 knots level flight. Could do better with attitude assuming coordinated turns.
https://photos.app.goo.gl/A0niEc6ZAG84VKMn2+++
Code:from numpy import * from pylab import * from scipy.interpolate import * # t sec az deg az_data = array([ [12 + 10./30, -43], [13 + 10./30, -44], [13 + 20./30, -45], [14 + 19./30, -46], [15 + 13./30, -47], [16 + 13./30, -48], [18 + 0./30, -49], [21 + 6./30, -50], [23 + 6./30, -51], [24 + 18./30, -52], [26 + 6./30, -53], [27 + 18./30, -54], [29 + 6./30, -55], [30 + 13./30, -56], [31 + 19./30, -57], [32 + 25./30, -58], [33 + 0./30, -58] ]) el_data = array([ [12 + 10./30, -26], [13 + 19./30, -27], [16 + 6./30, -28], [18 + 25./30, -29], [21 + 7./30, -30], [23 + 13./30, -31], [25 + 25./30, -32], [28 + 1./30, -33], [30 + 1./30, -34], [32 + 7./30, -35], [33 + 0./30, -35] ]) rng_data = array([ [12 + 10./30, 4.4], [13 + 10./30, 4.3], [15 + 3./30, 4.2], [17 + 4./30, 4.1], [19 + 1./30, 4.0], [20 + 29./30, 3.9], [22 + 28./30, 3.8], [24 + 28./30, 3.7], [27 + 1./30, 3.6], [29 + 13./30, 3.5], [31 + 22./30, 3.4], [33 + 0./30, 3.4], ]) ts = data[:,0] ephem = interp1d(ts, data.T) azs = data[:,1] els = data[:,2] rngs = data[:,3] vs = data[:,4] az = interp1d(az_data[:,0], az_data[:,1]) el = interp1d(el_data[:,0], el_data[:,1]) rng = interp1d(rng_data[:,0], rng_data[:,1]) def pos(t): vel = array([258 * KTS, 0, 0]) return array([0, 0, 0])[newaxis] + vel[newaxis,:] * (t[:,newaxis] - az_data[0, 0]) NMI = 1852. HOUR = 3600. DEG = pi / 180. KTS = NMI / HOUR FEET = FOOT = .3048 rel_speed = (diff(rng_data[:,1] * NMI) / diff(rng_data[:,0])) / KTS t = arange(15, 30, .1) azs = az(t) els = el(t) rngs = rng(t) x = rngs * NMI * cos(azs * DEG) * cos(els * DEG) y = -rngs * NMI * sin(azs * DEG) * cos(els * DEG) z = rngs * NMI * sin(els * DEG) xyz = vstack([x, y, z]).T p = pos(t) ax = subplot(4, 1, 1) plot(az_data[:,0], az(az_data[:,0])) plot(t, -arctan2(y, x) / DEG) ylabel('Az [deg]') subplot(4, 1, 2, sharex=ax) ylabel('El [deg]') plot(el_data[:,0], el(el_data[:,0])) plot(t, arcsin(z / linalg.norm(xyz, axis=1)) / DEG) subplot(4, 1, 3, sharex=ax) ylabel('Range [nmi]') plot(rng_data[:,0], rng(rng_data[:,0])) plot(t, linalg.norm(xyz, axis=1) / NMI) subplot(4, 1, 4, sharex=ax) ylabel('Rel vel [kts]') xlabel('t [sec]') plot(rng_data[2:-1,0], rel_speed[1:-1]) import matplotlib as mpl from mpl_toolkits.mplot3d import Axes3D fig = plt.figure() ax = fig.gca(projection='3d') ax.plot([0], [0], [0], 'bo') ax.plot(x / NMI, y / NMI, z / FEET, 'r-') ax.plot(x[:1]/NMI, y[:1] / NMI, z[:1] / FEET, 'ro') xlabel('x [nmi]') ylabel('y [nmi]') ax.set_zlabel('z [feet]') fig = plt.figure() ax = fig.gca(projection='3d') ax.plot((p[:,0])/NMI, (p[:,1]) / NMI, (p[:,2]) / FEET, 'b-') ax.plot((p[:1,0])/NMI, (p[:1,1]) / NMI, (p[:1,2]) / FEET, 'bo') ax.plot((x + p[:,0])/NMI, (y + p[:,1]) / NMI, (z + p[:,2]) / FEET, 'r-') ax.plot((x[:1] + p[:1,0])/NMI, (y[:1] + p[:1,1]) / NMI, (z[:1] + p[:1,2]) / FEET, 'ro') xlabel('x [nmi]') ylabel('y [nmi]') ax.set_zlabel('z [feet]') show()
+++
That number there varies between 252 and 259.
The M number varies from 0.61 to 0.62, flipping at 254/255
Those numbers are a bit confusing, as 254 is not 0.61 of the speed of sound. However:
http://www.hochwarth.com/misc/AviationCalculator.html
Hence, the 254 number is CAS, Calibrated airspeed. It's not groundspeed, and it's not True Airspeed (TAS) which is actually 369 knots (which matches 0.61285*602, where 602 is the speed of sound in knots at 25,000 feet pressure altitude)
The groundspeed depends on the windspeed at 25,000 feet. An additional complication would be how this differers from the airspeed at 13,000 feet.
But how does your chart look with an aircraft ground speed of 369 knots?
+++
Assuming a simple difference there of 369-258, or 111, that presumably reduces your calculated closing speed to ~69 knots?
+++ During the entire period when the ATFLIR is locked on the object, the object’s speed can be estimated on a moment by moment basis.
At every moment during the locked-on period, the speed vector of the F18 can be projected onto the slant vector (the vector pointing towards the object). This gives the F18’s contribution to the closure speed:
Vc,F18 = V x cos(left) x cos(down)
Where V is the airspeed of the F18 in the ATFLIR display, ‘left’ is the angle to the left in the ATFLIR display, and ‘down’ is the vertical angle in the ATFLIR display.
The object’s contribution to the closure speed is:
Vc,obj = Vc – Vc,F18
Where Vc is the closure speed in the ATFLIR display.
If we assume that the object travels approximately along the same line as the F18 (plus or minus 20 degrees), but on a different altitude, the object’s real velocity can be estimated as:
Vobj = Vc,obj / (cos(left) x cos(down))
In this way I estimated the object’s speed at every second during two periods in the official GO FAST video, one period where the F18 is flying level (1:35-1:39) and one period where the F18 is in a stable banking position to the left (1:43-1:55).
The results are below.
(I also played a bit with the angle between the object’s line-of-motion and the F18’s line-of-motion, but until a deviation of plus or minus 20 degrees the results are basically the same.)
Conclusion: The average estimated speed of the object is 80 knots, and it seems to be traveling at a constant speed with a standard deviation over the entire lock-on period of only 7 knots (which could be caused by measuring errors of the sensors involved).
Note: If the real ground speed of the F18 is higher, the object’s speed is even lower…
T left down RNG Vc V ALT Vc,F18 Vc,obj V,obj
1:35 43 26 4,4 220 253 25000 166 54 82
1:36 45 27 4,3 210 254 25000 160 50 79
1:37 46 27 4,3 210 254 25000 157 53 85
1:38 47 27 4,2 200 254 25000 154 46 75
1:39 48 28 4,2 200 254 25000 150 50 85
T left down RNG Vc V ALT Vc,F18 Vc,obj V,obj
1:43 50 30 3,9 180 254 25010 141 39 69
1:44 50 30 3,9 180 254 25010 141 39 69
1:45 50 30 3,8 180 254 25000 141 39 69
1:46 51 31 3,8 180 255 25010 138 42 79
1:47 52 31 3,7 170 254 25000 134 36 68
1:48 52 32 3,7 170 255 25010 133 37 71
1:49 53 32 3,7 170 255 25000 130 40 78
1:50 54 33 3,6 170 255 25010 126 44 90
1:51 54 33 3,6 160 256 25010 126 34 69
1:52 55 34 3,5 160 256 25010 122 38 80+++See above. The true air speed is 369 knots, you might want to redo your post. Note: If the real ground speed of the F18 is higher, the object’s speed is even lower…+++ Great, thank you. This is what I downloaded from WaPo, it's 1080p.
I also uploaded it to YT:
Comparing the various versions now. My initial guess is the WAPO version is the version that was used to assemble the TTSA video, i.e. the WAPO version is less compressed and has slightly more pixel detail, debatable if it's actually more useful, though. Curiously, the WAPO video is interlaced.
Good grief, I wish TTSA would just release a link to the original video release by the DOD, not Youtube. Aren't these videos essentially property of U.S. taxpayers?
I'd love to recreate this in 3D. But, I suppose the specific details that I'd need about the ATFLIR camera are classified - CMOS/CCD sensor size/focal length/resolution?
(Interestingly, Luis Elizondo is on Fox News as I'm writing this post).+++Mick's backyard simulation might do well to be updated so as to simulate both the tracking and non-tracking segments of the footage. As it is, it only simulates the tracking portion of the footage. But just thinking about that simulation scene and fixing the camera to a background tree persuades me you're probably right, the ball will move across screen. But the camera motion needs to model the ATFLIR's. Why? That's what I'd expect from parallax. When you track the background, the object moves fast. When you track the object, the background moves fast. The stabilized footage essentially does open-loop tracking, and then continues with closed-loop tracking after lock-on.+++
Calibrated airspeed is the speed read by an airspeed indicator that has been calibrated for the air pressure at sea level. Could you explain the difference between calibrated airspeed and true airspeed?
True airspeed is the actual speed of the plane relative to the air outside the plane.
I presume that CAS is used in the display because in a fighter jet the CAS affects the maneuverability of the plane more than the TAS. i.e. you can do extreme maneuvers at a faster TAS at higher altitude, but it will be at the same CAS. So the pilot needs to know to know, for example ("is the CAS high/low enough to do a lag roll").
In this situation, at 25,000 feet barometer altitude the TAS is very roughly 1.5x the CAS (or more accurately 1.45x) Based on investigation in the GIMBAL thread, the NAR mode of the ATFLIR is 1.5° FOV (square) - although I think there was some small debate about that. Getoffthisplanet said: ↑I'd love to recreate this in 3D. But, I suppose the specific details that I'd need about the ATFLIR camera are classified - CMOS/CCD sensor size/focal length/resolution?+++ From Reddit:
https://www.reddit.com/r/Conspiracy...e_up_boys_youre_about_to_get_learnt_a_little/
Gimbal and Go Fast are both pieces of the same video it appears .... if you look to the right side of the sensor overlays you'll see a 4 digit code, in THIS VIDEO [GIMBAL] it is 1688 and supposedly shot in 2004 on a routine training mission. That is the laser PRF code set for laser guided munitions. The Go Fast video with the waves in the backdrop was east coast- that jets PRF code was also 1688 and shot in 2015. This DOES NOT HAPPEN. PRF codes are assigned to a specific aircraft for specific sorties and the odds of this PRF being recycled through service to a new aircraft when there are millions of combinations are just that- 1 in millions.Content from external source
Interesting. The display configuration is all essentially the same. The time code at the bottom is in seconds, with a difference of 991 seconds (16.5 minutes) between the end of GO FAST (4254) and the start of GO FAST (5245)
This suggests is just the pilot playing around with the ATFLIR seeing what he can lock on to.+++ Gimbal was reportedly shot off the coast of Florida in 2015. When the NY Post reported that Go Fast "was shot off the East Coast in 2015," I thought it's either the same video or they confused it with Gimbal, but I guess it is part of the same video. Are the voices similar? I guess the WSO is new to ATFLIR and doesn't identify flying objects very well.+++ Nice observation by the reddit poster, but the fact we don't have a place nor a time for the "GIMBAL" it could easily be said that it was part of the GO FAST time frame. I'm sure I will be corrected, but the GIMBAL video has never been really associated with the 2004 Nimitz video, correct?+++ So, this is the problem. We are seeing only a very small piece of what is going on it the jet. On the other DDI they would have their other system up, well in the case of a two seater FA-18, there is a total of eight DDI's (some call them MFD's). The pilot will typically have one DDI set to NAV and the other set for either RDR or SA. The WSO will have either ATK A/G or A/A on one DDI while the other is in FLIR mode with a configuration of TV or IR mode.
Depending on what A/A RDR you are using VS, TWS, RWD you will not always get RNG or Vc, Typically it is TGT instead of RNG when in combat configuration. We just do not have this information unfortunately.+++ Just doing this with a TAS correction for 45° and 55° During the entire period when the ATFLIR is locked on the object, the object’s speed can be estimated on a moment by moment basis.
At every moment during the locked-on period, the speed vector of the F18 can be projected onto the slant vector (the vector pointing towards the object). This gives the F18’s contribution to the closure speed:
Vc,F18 = V x cos(left) x cos(down)
Where V is the airspeed of the F18 in the ATFLIR display, ‘left’ is the angle to the left in the ATFLIR display, and ‘down’ is the vertical angle in the ATFLIR display.
The object’s contribution to the closure speed is:
Vc,obj = Vc – Vc,F18
Where Vc is the closure speed in the ATFLIR display.
If we assume that the object travels approximately along the same line as the F18 (plus or minus 20 degrees), but on a different altitude, the object’s real velocity can be estimated as:
Vobj = Vc,obj / (cos(left) x cos(down))
cos(45 degrees)*cos(27 degrees))*369-210 = 22.5 knots
cos(55 degrees)*cos(33 degrees)*369/254*256-160 = 18.9 knots
Indicating the object is flying away from the jet at around 20 knots. (although this all depends on the wind speed, and that's only the component of the objects motion in that direction)
Is everyone okay with the use of TAS not CAS, as explained previously?+++ A Paracaster with the handle of “Realm” has done his meticulous calculations and displays a spreadsheet graphic with a long explanation you can read at this link. He concludes that the object behaves like a bird, specifically an albatross named Albert.
https://www.theparacast.com/forum/t...udy-media-monitoring.19069/page-3#post-270457
Last edited by a moderator: 56 minutes ago+++ We can assume it's in level flight, so /cos(down) makes sense, but isn't the actual possible range of speeds between Vc,obj / (cos(left) x cos(down)) and Vc,obj / (cos(left) x cos(down)) ? I don't think we can infer what the component of the Vobj is in the horizontal plane perpendicular to the LOS, can we? Kaen said: ↑Vc,obj = Vc – Vc,F18 = object’s contribution to closure speed (negative means object is flying away from jet)
Vobj = Vc,obj / (cos(left) x cos(down)) = estimated speed of object in direction of jet+++Quelle; Metabunk, Mick West
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