Aa77 Fdr Heading Divergence, speed/heading vs Lat/Lon Options

[Aldo Marquis CIT]

"So, the conclusion is only valid if the DCA/ADW data is plotted correctly. It is not." - John Farmer aka BCR aka spcengineer, Feb. 21, 2011

"I thought those DCA/ADW plotted points looked familiar and they should, THEY ARE MINE!" - John Farmer aka BCR aka spcengineer, Feb. 22, 2011

(IMG:http://pilotsfor911truth.org/forum/style_emoticons/default/laughing1.gif)

HAHAHAHAHAHAHA, that is great. They can't even keep track of their own horseshit.

[onesliceshort]

HAHAHAHAHAHAHA, that is great. They can't even keep track of their own horseshit.

(IMG:http://1.bp.blogspot.com/_axwEeSXAOSk/SdKz_g3SRsI/AAAAAAAABC4/PeL0gDctc9s/s400/Bullshit_Detector.gif)

(IMG:http://pilotsfor911truth.org/forum/style_emoticons/default/biggrin.gif)

[rob balsamo]

lol.. Farmer is getting old guys... i suppose we should give him a break (maybe not, considering all the libel he spouts). He probably was sharp in his prime and now he is realizing he isnt what he once was and trying to hold onto anything he possibly can to make himself feel better. When he figures out his mistakes, he goes ballistic.

He is probably trying to get the mods to delete the thread, just as he deleted all his other BS from his own website(s).

I suspect it is probably getting close to the time where Farmer once again tells JREFers that they can "kiss his ass".

(IMG:http://i47.photobucket.com/albums/f178/myphotos1960/Farmer_Kiss_My_Ass.jpg)

[tumetuestumefais...]

So I did the Track Angle/Groundspeed plot from the "point of impact" again measuring in fractions of centimeters and caring to exactly fit the angle and then I've compared it to the Lat/Lon track. A divergence in the same direction like with True Heading/Groundspeed is still there but much less visible by bare eye -and with quite a big scatter given most probably by the inaccuracy of the Lat/Lon coordinates- for me to be able to somehow visualize it directly from the GE. So I've measured the distances on the perpendicular joins between the Lat/Lon track 1 second nodes and the Track Angle/Groundspeed trajectory, I've put it into the spreadsheet and then I've made a graph including linear trend:
(IMG:http://xmarinx.sweb.cz/LatLon_vs_TrackAngle-GS.png)
It looks like there is still a lateral displacement trend in the same direction (it is counter-wind) of ~34 meters/min (- for comparison with the True Heading/Groundspeed there it is ~460 meters/min).
Any hints what could be the reason for this?
What is also interesting that when one looks at the spline the divergence trend appears mainly in the second half of the graph.
Maybe I should go further to see how the trend continues through the 330° turn, where we can most probably see if it is possible to attribute it to an instrument inaccuracy or not.

Here the plot without the radar tracks:
(IMG:http://xmarinx.sweb.cz/Latlon_TH-GS_TA-GS.jpg)
blue-Lat/Lon violet-Track Angle/GS red True heading/GS
you can see the TA/GS-Lat/Lon divergence is not much visible.


Now back to the comments.
First. The plot of the true heading/groundspeed is NOT adjusted for wind. I don't much know how to adjust it, because the wind can considerably change with altitude, especially close to the ground and anyway only what I have is the wind record where is the 5.1 m/s at DCA 9:41.
First I've thought the divergence has a major part in the wind pushing the plane, but then I was allerted that I have the wind reasoning completely wrong because the wind was blowing in the oposite direction from NNW not to NNW, which is more or less against the vector of the divergence - in commonman words the direction to which the plane swerve from the way given by lat/lon is against the wind. So I have difficulty to understand what is there going on, because the wind triangle doesn't work on it. (IMG:http://pilotsfor911truth.org/forum/style_emoticons/default/dunno.gif)
Any hints?

A note to Mr. Farmer objection about credits, I used his file dcaiadadwbwicombined.xls for initial plots. But my positions of the radar blips are derived directly from Azimut/range values, adjusted also to the GE and carefully centered among the limit values, because even Mr. Farmer is using the 13 decimals behind comma in his coordinates they are a bit unexact, often off dozens of meters from the center of the tolerance, which is not useful for me, because I also look into other things (Apropos is here somebody having specifications of the DCA radar -I need at least the focal point altitude and I can't find it anywhere) - just for example I need to get the corrected position and lowest limit of the radar height of the 13:37:46.564 DCA blip (quite crucial for me) which is too inconsistent with the previous trajectory and I suspect it is a range misread due to partial terrain/buildings backscatter, because the target was already very low and there are quite tall buildings in the way.
So I appologize if Mr. Farmer feels offended I used his file to initially explore the situation -it was not intended to offend anybody.

[rob balsamo]

(IMG:http://xmarinx.sweb.cz/Latlon_TH-GS_TA-GS.jpg)

Pretty much what i expected. Thanks tume.

I wonder if Farmer and Beachy still thinks your original divergence was due to "magnetic declination".