[meteorite-list] calibrated stellar photo - york water

From: Mike Hankey <mike.hankey_at_meteoritecentral.com>
Date: Mon, 19 Oct 2009 12:29:55 -0400
Message-ID: <f0a794130910190929l50a7757avc6e51283044081e1_at_mail.gmail.com>

Dear List,

I know this is not as exciting as the Grimsby meteorites, but its
something I've been working on the last few weeks and I wanted to
share it with the list.

I have logged a lot of hours searching for meteorites from the PA
fireball and to date have not been able to find anything. Searching in
the same general area over a long period of time really starts to wear
on your physche and a few weeks ago I started to get consumed with
doubt regarding the area I was searching. I had found some new videos
and knew that we had never been able to properly analyze the data from
the original York Water video. I believed if we could properly analyze
that data and incorporate it into the current trajectory it might be
able to improve our projections and lead us to a new search area.

A couple of meteor experts suggested making calibrated stellar photos
of the direct sighting videos in an effort to improve the input data
used in the projections. The first attempt for making the calibrated
photo would entail busting out the jpegs from the original AVI and
then stacking the images like you would stack an astro photo. Faint
stars could exist in the frames that would not be visible in a single
frame but would become apparent after stacking 100 or so frames. If
this approach failed then new video would need to be shot that would
include stellar objects.

I started with the York Water video as this was a great capture but
very distorted due to the fish-eye lens. I tried stacking but got no
stars. A friend tipped me off to the fact that the full moon would be
rising in the east on Oct 4th and Oct 5th. I coordinated with York
Water to capture video from these nights. Using this new moon footage
I was able to pair up 9 frames of the meteor video with very close
references to the full moon at different points of time. In 3 cases
the meteor was a perfect match to the moon's location.

Here is the York Water calibrated stellar photo:

http://www.mikesastrophotos.com/wp-content/uploads/2009/10/york-water-calibrated-summary-simple.jpg

Here is the star map that I created after analyzing the calibrated photo:

http://www.mikesastrophotos.com/wp-content/uploads/2009/10/york-moon-star-map.jpg

I traced a straight line through the meteor locations and down to the
horizon. Using imperfect measurements I came up with an approximate 67
degree angle at the horizon. I drew a line in google earth at that
angle from the york water location and it intersected Rob's 0km marker
almost exactly. I find this reassuring and pretty incredible
considering Rob used only the Pittsburgh video and the astro photo in
determining his 3D model. Mad props to Rob Matson on his meteor
trajectory skillz -- Rob I think you could triangulate a meteor in
your sleep. :)

http://www.mikesastrophotos.com/wp-content/uploads/2009/10/york-water-map.jpg

I'm not sure about the precision of my measurements or star chart but
I know its pretty close (i'm sure it could be improved some). I'm not
sure if this new input data can be used to make minor improvements to
the trajectory, velocity estimates or angle of descent but if there is
anyone out there who worked on plotting the PA fireball and wants to
take another crack at it with this information I would love to hear
from you.

I know several people on the list worked on getting the ALT-AZ
readings from the york video using compasses and field surveying
techniques and had a hard time due to the distortion from the camera.
I wanted to share this approach to analyzing security footage in case
this situation ever arose in the future. Using a calibrated photo
eliminates a lot of guess work.

I have requested the original raw footage of the Pittsburgh video from
Alison Kruse and I hope to be able to pull out more stars in that
footage using the stacking technique.

My conclusion after working with the York calibrated photo is that I'm
searching in the right area, but just need to look harder. I find it
amazing and inspiring that Mike Farmer can fly to Ontario and find a
meteorite on his first day.

The new information from the York video and the excitement from
Ontario has given me a jolt of positive energy and a boost to morale
-- exactly what I need to continue searching the corn fields of
Lancaster PA.

To see the full post about this exercise follow this link:

http://www.mikesastrophotos.com/baltimore-pa-meteor/york-water-calibrated-stellar-photo/

Thanks,

Mike Hankey
http://www.mikesastrophotos.com
Received on Mon 19 Oct 2009 12:29:55 PM PDT