(meteorobs) Re: Fireball Network


        Dr Jeremy B. Tatum, an astronomer at the University of Victoria and
member of MIAC, trained 27 volunteers to go out and interview people that
observe fireballs.  These interviewers are equipped with measuring devices
such as compasses and clinometers so azmith angles and elevations can be
measured.  This spring we had three fireballs in a rather short period of
time.  It was found that information collected from un-trained observers is
often lacking in accuracy.  An instrumental method of recording these events
would be highly desirable so accuracy could be improved.  I, (Ed Majden)
designed a simple device to record the shaddows cast by very bright bolides.
About the brightness of the full moon as that is the type of fireball that
could possibly result in dropping a meteorite.  This device uses an
inexpensive security video camera looking down at a vertical pole of known
length mounted in the center of a polar grid.  The shaddow cast by the
fireball indicates direction and the length of the shaddow measures height
above the horizon.  The information is recorded on a VCR, which most every
one has these days.  This device is now undergoing testing.
        Sandia Laboratories of New Mexico heard of our activities and
selected the University of Victoria and this network to operate a video
recording system that they have developed.  This device is similar to the
all-sky cameras used during IGY to record Auroras, except that it uses a
video camera to image the sky in a convex spherical mirror.  This device
will record the fireball on video tape.  Again, inexpensive home type VCRs
are used, recording on T-160 tapes in the extended play mode providing 8
hours of recording time on a single tape.  It would be too time consuming to
monitor each recording so the public still has to be used to report fireball
events with the time.  Then the operator can quickly go to this area on the
VCR tape to search for the image of the fireball.  The recorded images will
then be measured.  The fireball cameras are operated by David Balam, a
research associate at UVic., Bill Weller, a physicist at Malaspina
University College in Naniamo, and Ed Majden, an associate member of MIAC
and amateur meteor specialist living in Courtenay.  Shaddowgram, units will
be operated at these locations also.  Ed is also designing a photographic
all-sky camera using a 30mm focal length Russian fisheye lens on 4 X 5 cut
film.  This camera will have a rotating interupting shutter to measure
velocities etc.  It will only be used when Ed is using his spectrographs to
record meteor spectra.  Mostly during shower peaks.  Conventional
photographic methods are labor intensive so that latter are employed when
time permits.
        Observations from the public are still important as observations
from different locations are necessary to refine and compute the fireballs
path through the atmosphere and to predict a possible fall area.  

Edward Majden                         epmajden@mars.ark.com
1491 Burgess Road                     Meteor Spectroscopy
Courtenay, B.C.                       AMS Affiliate
CANADA  V9N-5R8                       MIAC Associate