The METSIM software
The Leonid return in 1998 and 1999
will probably be a very
challenge to visual meteor observers. In fact it will be quite difficult to
obtain reliable activity data from visual counts. Yet it is still unclear how to
judge about the 1966 visual counts. A calibration of those data by imitating the
1966 method may provide us with more reliable ZHRs of the last Leonid return.
Their method then was simply "estimate the number of meteors visible
when looking at the sky for one second"
. This method can be simulated
by the Meteor storm
written by Sirko Molau, based on an idea of Hartwig
Meteor Storm Simulation
This program displays a meteor storm to investigate visual observing
techniques under very high meteor activity. It tries to simulate the
situation as accurate as possible. Meteors are displayed as elongated
moving objects. They do have different brightnesses, light curves,
velocities, directions, persistent trains, etc as in reality. The sequence
shooting stars is computed with an exponential distribution. Thus, the
often reported 'cluster effects' become clearly visible. A number of
background stars make the display more realistic.
Download the Software HERE
run the program, a fast PC / graphics card is necessary. The simulation
should be executed under DOS.
It is advised to do the first simulations with a clock displayed. If the
calibration works well, the clock should run approximately in real time.
Three simulation modes are available:
* In training mode, you enter a
number of meteors per second and the
program shows you, how that will
* In static test mode, the program displays a fixed number of
you have to estimate.
* In dynamic test mode, the
simulation runs for a longer time with
gradually changing activity.
You are to estimate the meteor number each
minute, which allows the
study of systematic errors.
On startup you can choose a number of parameters like
* the position of
the field of view with respect to the radiant,
* the geocentric velocity and
population index values of the meteor
* the number of
The flag -help lists all available options.
The software has some limitations:
* Effects like variable meteor
numbers due to the position of the field of
view (near zenith or
horizon, near or far from the radiant) are not
simulated, as these
effects have only to be modeled properly when
computing the ZHR. Main
aim of the program is to study, whether visual
observers are able to
give good estimates of a larger number of shooting
stars visible in a
certain field of view. So, the long-time average of
matches exactly the given number.
* For the same reason, there are no very
faint meteors displayed, which
are extremely difficult to see. Every
observers should be able to see all
simulated meteors, avoiding side
effects from different 'limiting
* The angular
velocity of meteors and the lengths of their trails is not
according to some formulae, but was intuitively adjusted to look
realistic. This may be improved in a future release of the program.
Enjoy the simulation!