Website first online in 2000
This version went online in 2017
Astronomical software
This page provides a number of astronomy software applications which I wrote.
They are of two types:
- Windows .NET programs
- Excel spreadsheets
The .NET programs were written in Visual Basic and compiled in Microsoft
Visual Studio.
Note: download and use of these programs is at your own risk. Although I always test them before
deployment, I cannot guarantee they always work correctly.
Note 2: Some antivirus programs complain with warnings about some of the programs below. Ignore those: the programs are 100% harmless, but unfortunately antivirus programs sometimes give false positives.
This software is free. However, if you use and like it, I appreciate a donation at your discretion.
NOTE: If the software produces incorrect/malformatted output, this is probably something to do with the regionalization settings of your pc. This is notably the case if your country uses the comma as the decimal separator instead of a point. Adjust your Windows regionalization settings so that the decimal separator is a point, and it should work fine (in my newer software, the software itself enforces a point as the decimal separator but some of the older programs still might have this issue).
SkyTrack 3.1 - This program is of interest to satellite observers. SkyTrack is a program that, from a TLE, for a user-defined time window and in user defined time steps calculates the groundtrack (sub-satellite points) of the satellite, it's altitude above Earth, its range to the observer, its position in the sky from a user-defined observing location (both as RA/DEC and Azimuth/Elevation), whether it is sun-illuminated or not, and as optional output also a Doppler-corrected frequency and/or ECEF X,Y Z coordinates and velocity vector. Output is numerical, not graphical, and can be saved to a .txt file. However: as of version 2.5, there is an option to generate a .kml file for visualization in Google Earth. Version 2.6 corrects a bug where for sites with altitudes well above MSL, a wrong AZ/ELEV and RA/DEC was given. Version 2.7 corrects a bug where site latitudes/longitudes were incorrectly written away for southern and western hemisphere sites. Version 2.9 adds solar altitudes at the observing site, and the option to correct the calculated sky elevations for atmospheric refraction. Version 2.9.7 contains some minor bug fixes. Version 2.9.8 produces output faster. Version 2.9.9 corrects an error in KML generation. SkyTrack 3.0 corrects an error where for dates before 1-1-2017, a wrong value for delta TAI-UTC was used. Version 3.1 adds the phase angle to the output.
Download Current version: SkyTrack 3.0
type: Windows .NET executable (64-bits)
original version 1: 27 January 2019
date current version 3.1: 25 Nov 2024
IOD Entry 1.2 - This program is of interest to satellite observers. IOD Entry is a program
that creates satellite observation data lines in IOD format. IOD
is the format used by international amateur satellite observers to communicate positional measurements on satellites. The resulting IOD
formatted data lines can be saved to a .txt file and saved to an incremental archive file.
Download Current version: IOD Entry 1.2
type: Windows .NET executable
original version 1: 1 November 2017
date current version 1.2: 19 June 2020
EasyPPAS 1.0 - This program is of interest to satellite observers. EasyPPAS 1.0 is a program
that creates satellite photometric data lines in PPAS format. PPAS (Photometric Periods of Artificial Satellites) is the format used by international amateur satellite observers to communicate brightness variation measurements on satellites. The resulting PPAS
formatted data lines can be saved to a .txt file and saved to an incremental archive file.
Download Current version: EasyPPAS 1.0
type: Windows .NET executable
original version 1: 8 May 2019
date current version 1.0: 8 May 2019
TLE from Proxy 1.0 - This program is of interest to satellite observers. TLE from Proxy is a program
that estimates a TLE for a new launch, based on a proxy TLE from a previous similar launch. Inputs are a TLE from a previous similar launch, the date and time of that launch, and the date and time of the new launch. The resulting TLE can be saved to a .txt file.
Download Current version: TLE from Proxy 1.0
type: Windows .NET executable
original version 1: 11 November 2017
date current version 1.0: 11 November 2017
TLEMerge 1.0 - This program is of interest to satellite observers. TLEMerge is a program to merge TLE's in a TLE file with more recent TLE's from a second TLE file, replacing only those for which a more recent TLE is present in the second file. It also adds TLE's for objects in the second file not present in the first file. Output is a new, merged file.
Download Current version: TLEMerge 1.0
type: Windows .NET executable
original version 1: March 2024
date current version 1.0: March 2024
TLE2LINE 1.0 - This program is of interest to satellite observers. TLE2LINE is a program that converts satellite orbital elements
in 3le TLE format into a single data line per TLE. The data in this single line per TLE are comma-separated for easy import into a spreadsheet.
In addition to the basic elements from the TLE's, extra data are added to the line: semi-major axis in km; apogee in km; perigee in km; daily RAAN-precession.
Download Current version: TLE2LINE 1.0
type: Windows .NET executable
original version 1: November 2018
date current version 1.0: November 2018
TLExtract 3.7 - This program is of interest to satellite observers. TLExtract is a program
to extract TLE's from a larger TLE file, based on a custom-set selection criterion (for example, you can set it to select all TLE with perigee above a certain height; or all TLE with "USA" in the object name; etcetera). Version 3.0 has drastically improved performance when operating on large files, and solved a problem with hidden line carriers. Version 3.7 added several new selection options (e.g. RAAN and orbit type) and option to copy output into the input window for further selection.
Download Current version: TLExtract 3.7
type: Windows .NET executable
original version 1.0: 15 February 2018
date current version 3.7: 11 April 2018
COLA 1.0 - This program is of interest to satellite observers. COLA is a program to calculate
when two satellites come to within a user-defined approach distance of each other. It can also be used to asses manoeuvre
times, by using a pre- and post-manoeuvre orbit as input.
Download Current version: COLA 1.0
type: Windows .NET executable
original version 1.0: 15 August 2022
date current version 1.0: 15 August 2022
Vect2RADEC 1.0 - This program is of interest to satellite observers. Vector to RA/DEC takes an .sp3 file with SWARM GPS positional vector data and a file with observation times (and optionally observational positions at those times) and then calculates the RA/DEC of the SWARM satellite (and optionally the residual with the observed positions) at the given observation times. This allows to calibrate camera/lens and timing accuracies.
Download Current version: Vector to RA/DEC 1.0
type: Windows .NET executable
original version 1.0: 1 May 2023
date current version 1.0: 1 May 2023
PlaneSearch 1.0 - This program is of interest to satellite observers. PlaneSearch is a program to help conduct a planar search for a lost object. It creates a large number of clones of an original input orbit, at 5-degree intervals in Mean Anomaly. This effectively creates clones spreading over the full orbital plane. Loaded into predictive planetarium software like Heavensat, it shows you where the orbital plane is located in the sky, and how it moves over the sky in time, aiding you in a survey of the orbital plane.
Download Current version: PlaneSearch 1.0
type: Windows .NET executable
original version 1.0: 20 November 2018
date current version 1.0: 20 November 2018
Plane X 1.0 - This program is of interest to satellite observers. Plane X is a program
to calculate the two moments in the day that the orbital plane of a satellite crosses exactly over a given location on Earth.
Download Current version: Plane X 1.0
type: Windows .NET executable
original version 1.0: 6 April 2018
date current version 1.0: 6 April 2018
Doppler 1.0 - This program is of interest to satellite observers. Doppler is a program to calculate the Doppler shift of a radio signal emitted by a satellite, for a given receiving location.
Download Current version: Doppler 1.0
type: Windows .NET executable (64 bits)
original version 1.0: 5 Februari 2019
date current version 1.0: 5 Februari 2019
HEXtrans2ASCII 1.0 - This program is of interest to radio satellite observers. It is a program to translate hexadecimal telemetry dumps to ASCII, making any plain ASCII text in it visible (e.g. satellite identifiers, plain text messages).
Download Current version: HEXtrans2ASCII 1.0
type: Windows .NET executable (64 bits)
original version 1.0: 10 December 2023
date current version 1.0: 10 December 2023
LST 2.0 -
This program calculates the mean and apparent Local Stellar Time.
Results can be saved to a .txt file.
Download Current version: LST 2.0
type: Windows .NET executable
original version 1: 2017 (Windows console version)
date current version 2.0: 29 October 2017 (.NET version)
SOLLONG 3.1 - This program is of interest to
meteor observers. SOLLONG 3.1 is a program that calculates the J2000 Solar Longitude for
a given date and time. It also calculates the Julian Day and estimates
Delta T. It employs the full VSOP87 theory and includes a correction
from the mean dynamical equinox to FK5. Results can be saved to a .txt
file
Download Current version: SOLLONG 3.1
type: Windows .NET executable
original version 1: 2016 (Windows console version)
date current version 3.1: 29 October 2017 (.NET version)
XTerminator 1.0 - This program calculates the geographic position of the terminator (the day-/night line) on Earth for a given date and time.
Download Current version: XTerminator 1.0
type: Windows .NET executable
original version 1.0: 3 June 2020
date current version 1.0: 3 June 2020
Hohmann transfer 1.1 - This program is of interest to satellite observers. Hohmann transfer is a program
to calculate the delta V needed, and the amount of fuel needed, for a Hohmann transfer to a higher orbit.
Download Current version: Hohmann transfer 1.1
type: Windows .NET executable
original version 1.0: 10 April 2018
date current version 1.1: 12 April 2018
D-orbit 1.0 - This program is of interest to satellite observers. D-orbit is a program
to calculate the delta V and the amount of fuel needed to deorbit a spacecraft.
Download Current version: D-orbit 1.0
type: Windows .NET executable
original version 1.0: 12 April 2018
date current version 1.0: 12 April 2018
HtoSize - H to Size gives an estimate of the size of an asteroid based on its H parameter.
Download Current version: HtoSize 2.0
type: Windows .NET executable
original version 1: 2005 (Windows console version)
date current version 2.0: 2018
METORB 10 - METORB is an Excel spreadsheet to calculate meteor orbits from
supplied radiant and speed information. In order to work with it, you
will also need Planeph
or similar software to calculate heliocentric X Y Z positions and
speeds of the Earth.
Download Current version: METORB 10
type: Excel spreadsheet
original version 1: 2004
date current version 10: October 2017
Zenitat 3 - Zenitat 3 is an Excel spreadsheet that calculates the zenit
attraction of a meteor from a given geocentric velocity and true
radiant altitude. Useful for calculating the apparent radiant of slow
meteor streams with the radiant low in the sky.
Download Current version: 3
type: Excel spreadsheet
original version 1: 2004
date current version: 2004
D' Crit - D' Crit is an Excel spreadsheet that compares two sets of
heliocentric orbital elements and calculates Drummond's D' criterion, a measure for the
similarity of the orbits.
Download Current version: 1.0
type: Excel spreadsheet
original version 1: 2001
date current version: 2001
SOFTWARE BY OTHERS:
The following meteor and satellite related software is
hosted here with permission of the developer:
AstroRecord 3.2 - AstroRecord by Marc de Lignie is astrometric software to measure
wide-field astronomical imagery.
It was developed for astrometry on widefield (D)SLR meteor imagery
(typically with 50mm focal length lenses, i.e. field of views up to 40
degrees) within the Dutch Meteor Society in the 1990'ies. The software
corrects for image distortions introduced by the lens system, by means of the "Turner" method.
The software loads black-and-white 8-bit .bmp imagery. With a modern DSLR and a
(sufficient quality) 35mm to 50mm focal length lens, the astrometric accuracy obtained is typically 5" to 7".
The astrometric limit of the software (inherent to the used somewhat
dated star catalogue) is around 2".
The version hosted on the IMO website will no longer install
under Windows versions beyond Xp. That is not a
problem with AstroRecord (the 32 bits version actually works fine under
Windows 10) but with the installer. Hosted here is a .zip file with all
necessary files, that circumvents the installer. Simply unzip the .zip
file into a directory C:/ASTROREC and it should work.
The Help-file of
the program provides guidance on to how to use AstroRecord. I also
included a pdf file that details the use, step-by-step, geared to
measuring imagery containing a satellite trail.
Download Current version: 3.2
type: Windows executable and related files
(Download hosted with permission by the developer, Marc de Lignie)