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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 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.

 

Metorb07.xls (45 kB) is an MS Excel application written by me, which calculates orbital elements for a meteor from its geocentric radiant position and speed. A test against several meteor orbits computed with professional software shows that the spreadsheet performs quite well. The spreadsheet works in conjunction with both my spreadsheet geo_rad.xls (see below), and with Planeph 4.1 which you can download at ftp://cdsarc.u-strasbg.fr/pub/cats/VI/87/, which you need in order to calculate accurate heliocentric ecliptic X, Y, Z coordinates and speeds of the earth, which my spreadsheet needs for input in addition to the meteor data. Planeph 4.1 is DOS software written by G. Francou & J. Chapront of the French Bureau des Longitudes.

geo_rad.xls (68 kb) is an MS Excel application written by me that calculates the geocentric radiant position and geocentric speed from an apparent radiant position and initial speed. Corrections are made for zenith-attraction, and diurnal aberration. Input data are the geographic position, initial speed of the meteor, date and time, and the apparent radiant azimuth and altitude. Output data are the RA and DEC of the apparent radiant, and the RA and DEC of the geocentric radiant, and the geocentric speed. These data can be fed into for example Metorb06.xls.

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 Vgeo generates a table with the altitude of the apparent radiant in steps of 0.5 degrees in true radiant altitude. The generated data are useful when you are observing streams with meteors of low velocity, under conditions of low radiant altitude.

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 Right Ascension and declination.

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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