WTC7 early movement summary
West edge trace by NIST, with my raw data overlaid...
The full vertical movement extent is shown.
NIST Moire measurement method in red, femr's subpixel tracing method in blue.
A closer look with raw data...
A quick normalised view of NW corner horizontal motion...
Cam3 - NW Corner - Top Field - Normalised
Top field shows same behaviour.
Cam3 - NW Corner - Bottom Field - Normalised - Zoom
Bit of a closer view.
Cam3 - Bottom Field - Normalised
A comparison with the West edge of the East Penthouse.
1) Doesn't show the same to-and-fro as the NW corner.
2) Uses the same static region subtraction data, so the to-and-fro is not a side-effect of the static point data.
3) Does show similar magnitude of movement shortly before release.
The to-and-fro is, imo, real.
(And useful data resulting from sub+/-0.2 pixel variance data.
Cam3 - Bottom Field - NW Corner Horizontal - Lowpass
Comparison between horizontal and vertical motion...
1) Both start motion around the 60s mark ?
2) Significant motion rate increase around 160s mark.
3) Significant motion is at an inflexion in direction.
4) real world scales are not equal.
Establishing a static reference point
Cam#3 - Top Field - Static Region - Vertical - Raw - 29.97 samples/s
1) The spike around the 95s mark appears to be caused by someone walking past the camera. His head is seen momentarily.
2) There doesn't seem to be any obvious shake caused by descent of the building.
Cam#3 - Bottom Field - Static Region - Vertical - Raw - 29.97 samples/s
Cam#3 - Both Fields - Static Region - Vertical - LowPass - 29.97 samples/s
1) Excellent correlation between upper and lower field motion after filtering.
Cam#3 - Top Field - Static Region - Horizontal - Raw - 29.97 samples/s
Cam#3 - Bottom Field - Static Region - Horizontal - Raw - 29.97 samples/s
They are different
Created on 07/25/2011 02:51 AM by admin
Updated on 11/19/2011 02:33 AM by admin