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**Some of my meteor related MS
Excel applications**

Between 2001 and present, I wrote (sometimes with the help of Marc de Lignie and Casper ter Kuile) a number of MS Excel applications for various types of calculations relating to meteor astronomy. Most of it relates to meteor orbits. Among them is a spreadsheet which allows you to calculate orbital elements from a meteor's radiant position and speed.

*Disclaimer:*
these Excel applications come "as is", with no warranty. I do not
guarantee their working, or accurateness, although they've been tested
extensively. Note that download and operation of these spreadsheets is at your
own risk. If you use results of the applications made available here in
publications or presentations, I appreciate if you acknowledge your use and the
source of the applications. For *Metorb08*, 85, reference: M. Langbroek: A
spreadsheet that calculates meteor orbits. *WGN* 32:4 (2004), 109-111.

(These Excel applications are provided as
freeware. But if you are very enthousiastic about them, you may always do a donation
through PayPal, which is safe and reliable, using the button above).

**NEW, Code fix (21/05/2007): Metorb85.xls (100 kb) **
calculates a meteor's orbit from the meteor's ** apparent radiant** and initial
speed, correcting for zenith-attraction and diurnal aberation to obtain the
geocentric radiant and orbital elements. This version fixes an error in the epoch conversion of the radiant coordinates (with thanks to Enrico Stomeo, who spotted the error in Metorb08).

It is **Metorb07.xls**
and **geo_rad.xls** integrated into one spreadsheet. For description of
components, see * metorb07.xls* and * geo_rad.xls* entries below. If
you use results of this spreadsheet in publications or presentations, please reference:
M. Langbroek: A spreadsheet that calculates meteor orbits. *WGN (J. IMO)*
32:4 (2004), 109-111.

**Metorb08.xls** (95 kb)
calculates a meteor's orbit from the meteor's ** apparent radiant** and initial
speed, correcting for zenith-attraction and diurnal aberation to obtain the
geocentric radiant and orbital elements. It is

**Metorb07.xls**
(45 kB) is an MS Excel application written by me, which calculates ** orbital
elements** for a meteor from its

**geo_rad.xls** (68 kb) is an MS Excel application
written by me that calculates the * geocentric* radiant position and
geocentric speed from
an

**d_crit.xls**
(28 kB) is an MS Excel application written by me, which allows you to formally
compare two orbits by means of calculating the ** D' criterion of Drummond**,
a slightly more sophisticated version of the classic Southworth-Hawkins
D-criterion.

**zenitat3.xls
**(93 kB: version
updated 04/07/2004: now works correct too for negative values of true altitude) is an MS Excel application written by me, which allows you to
calculate the ** zenith attraction** of a meteor radiant. The workbook
consists of two sheets. Sheet 1 allows you to calculate the zenith attraction
for a single input value for the true radiant altitude. In sheet 2,
an input value for V

**rad_alt.xls**
(67 kB) is an MS Excel application that calculates the radiant altitude.

**radcoord.xls**
(32 kB) is an MS Excel application written by me which converts the apparent ** altitude and
azimuth** of a point in the sky for a given time instance, into the
corresponding

**angl_sep.xls**
(24 kB) is an MS Excel application written by me which calculates the ** angular
separation** between two sky coordinates. Note that it only works well for
angular separations >1 degree and <180 degrees.

**JD.xls**
(15 kB) is an MS excel application written by me which calculates the ** Julian Day** for any given date and time in UTC.

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