| Version
3 alpha 0.0.4 |
This
version add the support for an asteroid database. |
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It
is now possible to show all the know asteriods down to a fixed
magnitude on any chart.
This is achieved by using a
database system to store and quickly retrieve the related
asteroid elements from the 200'000 MPCORB list.
As
there is still no documentation I give a brief explanation
here.
The first step is to load the MPCORB file to the
database, a simple selection can be done if you don't want the
full file. As the orbite parameter change over the time it is
possible to keep many version of this data. The program will
always use the nearest from the observation date.
The file
is available from :
ftp://cfa-ftp.harvard.edu/pub/MPCORB/
If you have difficulties to connect take a look at the
middle of this page: http://cfa-www.harvard.edu/iau/mpc.html
Then a computation of each asteroid magnitude is done
for the first of each month. This allow to roughly eliminate
the object too faint at a given date and speed up the daily
computation.
This process is slow due to the volume of
data to compute, I suggest you click this button just before
going lunch. |
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This
is all for the data preparation.
When a new date is
selected the position of all the asteroids brighter than the
limit is computed for 0h UT. This take 5 seconds for a
limiting magnitude of 18, but 15 seconds down to magnitude 20.
This position is used to choice the asteroid to display to
the chart, for this one the precise position at the time of
the observation is computed in a fraction of a second.
You can use the search box to locate any asteroid in
the database, enter the asteroid number or a part of the
asteroid name.
This asteroid is temporarily added to the
daily list even if is current magnitude is fainter than the
limit. This is an easy way to add a few faint target to the
chart. |
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To
use this new function it is necessary to install a MySQL
version 4 database server.
A simplified package to install
the database is available for the Windows user that don't
already own one.
On Linux I suggest you use the version
provided by your distribution, or if not at version 4.0 get it
from www.mysql.com. More precisely this is the MySql client
library that must be at version 4.0, the server itself can be
another version.
When the program is started for the
first time it will request the connexion parameters for the
database. I sugest you create a new database using the
corresponding button, this also load a sample file with 1000
asteroids.
If you don't want to use this feature juste
click Cancel on this screen to disable the asteroid display.
Computing all this data may cause some problem if your
processor is not powerful enough. In this case use less data
by limiting the number of object you load from the file.
I
also remark that on the same computer, the computing speed is
two or three time slower using Windows 98 than using Windows
2000 or Linux. | |
Updated
17-Dec-2003
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