[HSMS] MSSOFT Predicts the Directions of the Meteors.

Date: Sun, 16 Nov 1997 14:07:49 +0000
To: vhf@w6yx.stanford.edu
From:  Steve Harrison, Ko0u 
Subject: MSSOFT Predicts Directions

I originally posted this to other reflectors on 13 August; some may not have
seen it at that time so I'm reposting it here. Have fun in the Leonids!

There is an experimental subprogram included with OH5IY's MSSOFT 4.3,
versions 3 on up, that can help you visualize which directions should be
favored at any particular hour of the day during a shower. This program,
which is mentioned in the documentation, requires that you create a simple
ASCII text file which includes grids in a circle around you at some
reasonable distance, such as 1300 kM. While it takes some time to do this,
the resulting display may help you better understand  how meteor trails
favor particular paths.

An example grid-listing is included with the program for OH5IY's home in
southern Finland; you can either edit that file by replacing his listed
grids with your own list, or create your own file.

The program is called RMSH; when you invoke MSSOFT normally, a batch file
called MS.BAT calls up CMSH. In this case, you can copy the MS.BAT file and
rename it to, for example, MSR.BAT, to invoke RMSH. To modify the original
MS.BAT file, simply change the CMSH listing to RMSH instead.

To create your own grid list for use with RMSH, the following may be helpful:

1. Using a grid-distance program, such as N4AZI's "Grid Locator" or any
other, find grids that lie a particular distance from your home, such as
1300 kM. To start with, find eight grids spaced out every 45 degrees around
the compass.

2. Mark those eight grids on a grid map, and roughly trace a circle through
them such that the circle represents a radius of grids that are all about
the same distance from your own QTH; for example, 1300 kM. You do not need
to be very precise; +/- 100 or even 200 kM is probably more than good enough
for RMSH to at least show you what you might expect.

3. Write a list starting with the northernmost grid and going clockwise
around the circle back to the first grid. You must limit the list to no more
than 63 grids.

4. Either edit OH5IY's original list for his QTH, or create your own file,
with the list of grids, in the same format as Ilkka's original file. You can
rename his original file under another name; for example, OH5IY.LST or
whatever. Your list must now be named the same as his original list.

Then you are ready: type MSR.BAT (assuming you created that new batch file
to call RMSH instead of CMSH). The usual opening screen, with slight
modifications, will appear; type G for gradient, and ...... wait.....
and...... wait..... and.... wait. Yes, the program is running; you can see
it calculating, using the list of grids you created. My 486DX33 requires
roughly a minute to calculate through the entire list of grids. If you have
only a 386, you may want to reduce the total number of listed grids to, say,
24 or 36. My overclocked 6x86L-PR166+ takes about 15 seconds.

Eventually, the calculations will be completed and RMSH will display a
heading map. You can then hit your SPACEBAR to advance the program in 1/2
hour increments to see how, as the shower radiant changes origin with
respect to your own QTH, the favored paths shift around the compass. Be
careful that you do not exit the program before you want or you will have to
wait for it to recalculate again!

Please note that the best (that is, the longest lines) are predicted when
the radiant is at about 45 degrees; Ilkka mentions why this is in his

Ilkka cautions that, in his opinion, this program is of dubious value simply
because it is the result of a wild-eyed idea that he had (my own
interpretation of how he conceived the idea!) and its accuracy and thus
value and utility are as yet unproven. Perhaps some of you who made numerous
QSOs throughout the shower can coordinate your QSOs and observations against
the program's predictions?

Enjoy, Steve Ko0U/1


Comments: Rein, W6/PA0ZN

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