(meteorobs) Program to calculate fireball entry track in Earth's atmosphere, "fb_entry"

[Esko Lyytinen]

Hi all,


This program has been in use in the Finnish Fireball Working Group since 
the year 2005.

I will give this program available to those interested.

Today ( Sunday, Sept. 23, 2012 ) Maria Gritsevich had a presentation on 
this at the IMO IMC conference. Many thanks to Maria !
http://www.imo.net/imc2012/
program schedule
http://www.imo.net/imc2012/schedule

This program works in MS Excel and does need a genuine MS Excel.

It makes a direct fit into internally timed observations, if available. 
Non timed observations can as well be used.

There can be observations from one to several observing sites for a 
fitted track.

Because of the direct fit to internally timed observations, also single 
station meteors can be more or less solved, if a good and lengthy enough 
sky-track with (now needed) internally timed observations is available. 
Then the entry velocity can not be solved, but with some trial and 
error, a velocity that will give the beginning height consistent with 
the velocity can be reached.

The fit is by means of the Excel add in "solver".
Open Office etc sheets can not be used. The corresponding  "solver" of 
such is capable of solving only linear models, as far as I know.

Quite a good understanding of the principles are needed and some 
experience, to get full use of the program, and this may take some time 
to learn well. (There is however no need to get trough and understand 
all the "geometric calculations" in this.)

The program does not suit into much automatization. Each observations 
has its own line in the sheet and the timing of each must be adjusted 
with other lines or to have as unknown.

Local (in each observing station) alt-azimutal directions are in use.

You can download this from:
http://lyytinen.name/esko/fb_entry_vers_1.zip
This includes now, the ppt presentation, user instructions (planned to 
be continued, with furher example sheets) with two example sheets now 
and copyright information.
If you download this now soon, there may be some updates in this to came 
within a week or two maybe, into this same link. So, try also again 
later. Possible/hopeful later updates will have integer version numbers 
like 2,3,... So later on you can try with such altering of the link. I 
am also going to inform on such new versions in meteorobs.

This can be furher linked with Excel links into, for example Marco 
Langbroek's Metorb sheet to calculate solar system orbit. This can 
(different versions) be downloaded from.
http://marcolangbroek.tripod.com/metsoft.html

As to the fb_entry, if one may encounter problems in real use, I will 
try to give some level help via email.

Esko