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Observational
Analysis A1
12/31/2003
Analysis
of Chris Valentine's Image Data
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Note:
The use of outside or 3rd party text
and images on this site does not mean that the owner of that
material condones or agrees with all or any of the statements made
on these web pages. Some images may be enhanced to clarify
the content but should still express the original idea of the
author. |
One of the images
Chris Valentine created for his own website, (see links below), is referenced here as ChrisTimeline1.jpg.
This image has still shots from a video he took of the STS-107 reentry overlaid on a version of the STS-107 Ground Track.
Prior to February 1st Mr. Valentine received a
time table from NASA showing where to look in the sky, or
where to aim a camera, in order to spot the Columbia during the reentry of
STS-107. The table has azimuth, elevation and range for a number of
different time points and is custom oriented from your exact GPS location,
(Latitude and Longitude). By using this information it might be possible
to check the validity of the time and location data that is provided in the
STS-107 Ground Track documents.
Verification
of position data shown in images:
In
order to use this information we have to make a couple of assumptions.
First we have to assume that the clock on Chris's camcorder was set to the
correct time. Chris claimed to have set the time on it recently before the
event, and when NASA viewed his video they said his time was, "6 seconds
short of UTC", this is not unreasonable but would have meant approximately
24 miles of travel or 5.5° of angular displacement shown, so this can be
factored in. The only other assumption which is
really the most important one is, where was the camcorder pointed at the precise
times the different still shots were taken? Chris seems to be
confident that the
time stamps on his still shots correspond to the given data point times on the
ground track and the time table. Of course we have no reason to disbelieve
Mr. Valentine but he was obviously busy operating the camcorder and not taking
note of exactly where it was pointed.
We can make a fairly accurate check of the camcorders position relative to the
Ground Track by observing the lighting conditions of the sky in the still images
as well as the position of the sun. For Chris's location, 35.57445
N. Latitude and -111.52940 W. Longitude, on February 1st, 2003 the sunrise and
sunset
for Mountain Standard Time were 7:27 a.m. and 5:55 p.m. MST respectively per the
Farmers
Almanac, and the suns position would have been about 10.5° to the South at
sunrise. After performing this check by drawing check lines and measuring
the various angles it has been determined that the data shown in the image is
most likely accurate.
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Fig.
OA-A1-1
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Fig.
OA-A1-1 is an image created by Chris Valentine with still shots from
his reentry video overlaid on to pages from the STS-107 Ground
Track. To suit the purposes of this site the following
changes have been made,
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The
time table he received from NASA is placed in the lower left hand
corner.
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The
Line Of Sight (LOS) to various points along the flight path are
indicated by the red lines. along with the exact Latitude and
Longitude of the location, the time of the sighting and the angle
of the LOS.
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The Latitude and
Longitude of Chris Valentine's location has also been
added.
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Note:
Chris Valentine's original
graphic used to create Fig.
OA-A1-1 is here ChrisTimeline1.jpg.
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Diagram with a map indicating the
portion of the flight path viewable by Chris Valentine as
he recorded the STS-107 reentry. The image contains other
data such as the GPS coordinates for the end points and the time
on location for the shuttle as it entered and then left the
field of view.
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time animation tracing Columbia's flight path across the United States:
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Real time animation tracing Columbia's flight path across
the United States from 13:53:00 GMT to end.
Animation includes super imposed video compilation created
by Chris Valentine.
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In addition to the
compilation of amateur videos showing much of the STS-107 reentry
Chris Valentine's website contain homemade videos based on
different themes relating to Columbia and STS-107. Some are
set to music but they are all very entertaining as well as tasteful
tributes to Columbia and her crew. Everyone is urged to
visit his website and view or download the content.
Chris's main web-page www.chrisvalentines.com
Page relating to STS-107
www.chrisvalentines.com/sts107/
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At 6:54:44
a.m. MST, (13:54:44 GMT), the angle to Columbia's position on the image is 298°
as measured in a clockwise rotation from due North, while at 6:56:49 a.m. MST,
(13:56:49 GMT), the angle measures 80°. If we compare these values to
those of the time table, (298° Vs. 301.9° and 80° Vs. 84.4°), there seems to
be a minor 4° shift in the positions. When this is taken in context with the supposed
6 second discrepancy in the time stamp, the position shift is then closer to
1.5° and can be considered negligible. The
one aspect of the Columbia's position that cannot be determined easily from
the still photos is the altitude. In the few photographs that include a
ground level reference it is difficult to imagine that the shuttle is at the
elevation that the
time table claims would be necessary to observe it.
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Summary
/ Conclusions:
Chris
Valentine's graphic helps the investigation significantly showing that
through this portion of the flight the shuttle was where it was supposed to be
when it was supposed to be there relative to a geodetic location on the Earth.
Chris's video follows the Columbia
across the United States for about 680 miles and 173 seconds. The average
velocity of Columbia throughout the sighting was 14,150
mph, (calculated simply
by dividing the total distance traveled by the total time duration). The
officially reported velocity at the beginning of the sighting was 115,463
mph and at the end 113,983
mph with the average at 14,723 mph. The difference between the sighting
and the official values then was only about 4%. Although the shuttles altitude seems low it would be nearly
impossible to come close to an accurate value by taking angles and distances
from the still photos, therefore no determination can be made about it except
as a general observation.
This
information significantly cuts down on the number of variables that must be
considered when recreating exactly what happened to Columbia during reentry.
Chris Valentines observation ends at 13:57:35 just about 2 minutes before LOS
and orbiter breakup.
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Based
on data from the STS-107 Accident Investigation Time Line Rev. 15.
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Copyright
© 2003, 2004 ColumbiasSacrifice.com |
