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WXtrack - Satellite tracking

Information WXtrack em Português.

What the reviewers and users have said:

  • ".. a lovely piece of software" - Dave Garton, Satellite Applications Catapult, UK
  • "WXtrack is free, and is one of the best tracking programs that I have come across" - Radio Active April 2001
  • "...a satellite tracking program with a superbly crafted tracking window..." - Remote Imaging Group Journal 58
  • "...as up to date as any...", "...an impressive program..." - Monitoring Times, August 1999
  • "..the excellent "WXtrack" software .... I've used WXtrack in various outreach programs to high schools and recommend it." - Professor Bill Cowley, Director, Institute for Telecommunications Research, Satellite Comms Program Leader, CRC for Satellite Systems
  • "It was a pleasure to find a well-crafted package" - MD Robotics - makers of the Canadarm used on the Space Shuttle and Station
  • "I have used your program quite a bit now and I absolutely love it.  It is the best tracking program I have ever used and I have used them all I am sure :)" - Mark Kyle
  • "WXtrack is, by far, the most economical, flexible, and informative satellite tracking and display package available today.  It will be prominently displayed in our Data Processing Center to show the current, historical, or future location of our "A-Train" satellites and tracking sites.  Kudos to David Taylor for an exceptional satellite application" - Don Reinke, NASA CloudSat Mission Data Processing Center.  (CIRA)
  • "I wrote Quiktrak and for years it was the mainstay of the amateur and in some cases professional tracking world.  After seeing WXtrack, there is no need for me to ever revisit that offering. I am happy to register this software" - Bob McGwier, N4HY. Vice President for Engineering, AMSAT-NA
  • "WXtrack is a great program - I believe to be the best available." - Kevin Nice, Nice One Publishing Limited
  • The best Satellite Tracking program I've ever used and excellent support - Terry Gaff on Twitter.

WXtrack is used by many Universities and satellite enthusiasts across the world, and is also used within the industry - NASA, Surrey Satellite Technology.  Popular trackers such as GS-232 and WiSPDDE are supported.  If you would like a custom version for your project, just e-mail me.  See WXtrack in Embarcadero' Delphi Application Showcase!

icon-download.gif (908 bytes) WXtrack download
 WXtrack registration - help support continued development!
icon-download.gif (908 bytes) 3D display version - WXtrackGL download
Download SatCover download
icon-download.gif (908 bytes) SGP4 component download

Click for a bigger image
Multiple satellite tracking, with night-time shading.
(Click for more information)

Click for a bigger image
WXtrack in ISS mode, simulating the NASA wall display.
(Click for more information)

This program, which I have described in more detail,  is designed to predict the tracks of satellites both as paths above the earth, and as images produced by these satellites when scanning the ground.  It was designed for use during the early stages of my weather satellite receiving activities, when clouds and interference prevented easy identification of what I was actually observing!  Read more about using WXtrack.  The core orbit prediction elements are also available as a component that you can use in your own software.  This program is free for amateur use, but if you do wish to say "thank you", or you want technical support, or you want the advanced facilities, you should register WXtrack.

WXtrack can read processed satellite images from one or more folders of your choice, and present these images side-by-side with the ground track prediction. To make visual correlation easier, minute markers are produced on the predicted image to match those on NOAA APT transmissions.  Because of the graphics used in this program, it really requires a display of 1024 x 768 or better resolution, but it will work on 800 x 600.

Sample of the results using the full 18MB ground topography database.

Trackers and Antenna Rotators

WXtrack can drive a number of popular antenna tracking systems including controllers based on the WiSPDDE, Alfa SPID, AMSAT's LVB tracker, EA4TX's ARSWIN, Kansas City Tracker (RR.DLL and ON1CIM's KctTracker.exe), Las Vegas Boulevard (LVB from G6LVB), SeaTel, CX6DD (supports Yaesu GS232), EasyComm, IF-100 and FodTrack standards.  There are options for early startup of the tracker, antenna offset, flip-mode, antenna parking at pass end, running a command at start-of-tracking etc., and the program has a quick point-at-object mode for setting up your antenna with the sun, moon etc.
If you have another tracker that you would like supported, why not write to me and ask?

SDR - Software Defined Radio

SDRs are supported both through the excellent HDSDR software, and the equally good SDR# software with the DDE add-on.

Can I register and what do I get?

Users have asked for support on this software, and wish to say "Thank you", so I now provide extra facilities to users who do register WXtrack.  Commercial use of WXtrack requires purchase of a commercial licence.  The extra facilities are designed to make the program easier to use for regular users, and to extend the facilities available.

  • Extra facilities include
    • LARGE TEXT showing the tracker location from the other side of the room!
    • A Satellite Summary form is available by right-clicking the World Map display - includes MA display, nearest city in addition to azimuth, elevation range etc.
    • The latitude and longitude of the mouse on the World Map is given in, and the range and bearing from the home location.
    • Display extras e.g. some ISS mode features, multiple ground station footprint display.  Here's a screen-shot of the registered WXtrack in full ISS display mode.
    • Input from GPS for location and time setting, GPS prediction mode.
    • Extended Radar view functionality, especially for GPS,
    • Solar outage times for geostationary satellites - what are solar outages?
    • Satellite priority setting and automatic switch to next available satellite.
    • Option of restricting passes tracked to those in the pass list.
    • Automated daily reload of Kepler data,
    • Quick access to Sat Batch and Kepler Updater through the Tools menu.
    • The Tracker Test command is considerably enhanced by adding offset control, manual positioning and RA/Dec tabs - ideal for tracker setup and testing.
    • The tracker parking option is available.
    • Improved precision for some trackers (e.g. 0.1 degrees for Alfa SPID).
    • You can select finer time steps for the pass details list.
    • HRPT channel selection is possible with the Götz Romahn/Bob Barnes CX6DD tracker variant.

More information about some of the extra facilities.


  • System Requirements
    • Windows: Windows-7 and 8/8.1 are supported
    • Windows XP, Vista are likely to work, but are not tested here, and are not supported.
    • Processor: Pentium 90 or better, 200MHz or better recommended
    • Memory: 32MB or better, 64MB highly recommended.
    • Display: 800 x 600 resolution or better, 15-, 16- 24- or 32-bit colour recommended.
    • WXtrack works best with Normal font size.
  • The runtime Library Bundle listed below is necessary for WXtrack to function.  If you get error messages about missing DLLs when you try to run WXtrack, please consult the library notes page. 
  • Got a question?  Check out the FAQs.
  • There is a free self-help group that you can join here, where other users of the software can be contacted.
  • The Country & State boundary data is required if you wish to generate image overlays for adding to actual pictures with SatSignal, and for certain map projections.  If you have less than 32MB memory in your system and want to run overlays, it may be worthwhile downloading the Pre-compiled overlay bitmap as the program will struggle to generate the 31MB bitmap in a 24MB or less system!  Copy the expanded Overlay.bmp file to the program's executable folder.   If you wish to change grid-line spacing, add longitude and latitude annotation, or put the grid on top of the countries, please download MakeOverlay program listed under optional items below.
  • If you have a problem with your PC being permanently set on Daylight  Saving time, which happens with certain versions of Windows 98, try the Time Zone Editor from the Microsoft Windows 2000 Resource Kit.  This program, TZEdit, enables you to define your Time Zone details.  More information.
  • If you are driving a tracker in real-time, for more accurate tracking be sure your PC is keeping accurate time.
  • Updating the Kepler data is the first thing you should do after downloading.  Beware that the file modified date doesn't say how old the inside the file data is!


Beta version: This program is under continual development - check here for the latest update on top of a full install.

If you have customised any of the standard files, be careful not to overwrite your customised files with ones from the Zip archive!  Take the WXtrack.exe, the WXtrack.chm and the WXtrack.txt first.

Please note that while the Kepler orbit data supplied with the download was current at the time the download was prepared, it will be out-of-date by the time you start to use the program, and you may therefore get a warning about "WXtrack could find no satellite data".  If that happens, just run the Options, Kepler update... menu function.  You are responsible for ensuring that the program has up-to-date information if you want the most accurate results.  Registered users of the program can achieve this automatically with the Kepler Updater software, for which their WXtrack licence is also valid.

V3.8.48 Add Kepler Updater in Tools menu, remove obsolete Kepler Manager reference, better handling of certain artificial Keplers, improved sort-by-frequency in Kepler view form, add GLONASS and BeiDou to View|RadarPlor (may require Kepler data from CelesTrak), optional display of icon at home location (icon must be in file Home.ico in WXtrack directory, simple sample supplied from Emjois, your choice of size etc., update SPID tracker to all possible gearing options (1° to 0.1°), add short delay after sending a SPID command, add COM ports up to COM22, remember days-to-predict between runs, widen various date/time pickers, add Meteor-M satellites as having an AVHRR-like scanner, add option to close program from the command-line even if tracking, update Help to point to https://groups.io/g/SatSignal and show correct user name, enhanced caption clarity on tab controls, experimental: track geostationary satellites (on Tracker|Options), right-click satellite for larger text on primary, add satellite name & location to caption if tracker options Large track text checked, option for tracker click-on-satellite for frequency change (see: Tracker, Options, Radio, Manual switch), correct country boundary download URL, update Tools|ISS weather URLs, add Tools|My weather for user option URL, correct error when no satellites are assigned to a bank, refine full-screen code (F11).
V3.8.50 High visibility choice after satellite font choice forces bold text and solid background.  Get sort Kepler display by age working.  Handle no Kepler data found when all are too old.
V3.8.52 Substitute correct URL for "nasabare" Keplers, change timeline plot non-UTC start point, option for two decimal digits for greater precision with DDE.  Kepler update.

Please be careful not to overwrite your current Kepler data, or other local customised data, with out-of-date info!

Please note that Windows-XP and Vista support has been dropped in versions after V3.8.26, and although the software should continue to work, it is no longer guaranteed or supported on older versions of Windows.  In Windows-7 and later it is recommended to install WXtrack into C:\Tools\SatSignal\WXtrack\.  If installed into C:\Program Files\ some functions will not work.

Using WXtrack with ARSVCOM, ARS-USB interfacing explained

The ARSVCOM emulates several interfaces as Yaesu GS232A or Prosistel "D".  So, you don't need to modify anything in WXtrack, because I suppose you already support the GS232A or PST "D".

Just some simple notes about the new ARS-USB Product:

The ARS-USB Product includes the ARS-USB Interface and a program called: ARSVCOM.  Once the ARS-USB Interface is connected into a USB Port (Windows, Linux or MAC OS X) a serial/COM port is added to the computer (Example: COM5).  Without any additional program, any program can use this COM port and send/receive commands from the unit.  The ARS-USB emulates a Yaesu GS232A interface, so it's mandatory that the program send the same commands as a Yaesu GS232A.

If a customer wants to use the ARSVCOM (a graphical and friendly user interface) then he must do as follows:

1 - First, the ARSVCOM can create an additional Virtual COM Port (Example: COM7) and via this virtual COM Port, can emulate several interfaces (GS232, PST "D", etc).

2 - Then, he must configure the ARS-USB Port assigned by Windows (example: COM5) so the program can control the interface.

3 - Finally, configure a 3rd party program (Example: WXtrack) to use the Virtual COM Port (COM7).

Basically, WXtrack will send GS232A commands to the ARSVCOM and those commands will be processed and routed to the USB Port.

(Information kindly supplied by Paolo).

... em Português ... Explicação para o uso do WXtrack com interface USB ARS ARSVCOM

O ARSVCOM emula várias interfaces como Yaesu GS232A ou Prosistel "D".  Assim sendo, não precisa de modificar nada no WXtrack , porque eu suponho que você já suportam o GS232A ou PST "D".

Apenas algumas notas simples sobre o novo ARS- USB do produto:

O Produto ARS- USB inclui a interface ARS- USB e um programa chamado: ARSVCOM.  Uma vez que a interface ARS - USB é conectada a uma porta USB (Windows, Linux ou Mac OS X) ou a uma porta serial/COM adicionada ao computador, (exemplo: COM5).  Sem nenhum programa específico, qualquer programa pode utilizar esta porta COM e enviar/receber comandos da unidade.  A ARS - USB emula uma interface Yaesu GS232A e por isso é obrigatório que o programa envie os mesmos comandos para o Rotor Computer Interface Yaesu GS232A.

Se um operador quer usar o ARSVCOM (uma interface gráfica e amigável), então ele deve fazer o seguinte:

1 - Em primeiro lugar, o ARSVCOM pode criar uma Porta COM virtual adicional (Exemplo: COM7) e através desta Porta COM virtual, pode emular várias interfaces (GS232, PST " D ", etc).
2 - Em seguida, ele deve configurar a Porta ARS - USB atribuída pelo Windows (exemplo: COM5) para que o programa possa controlar a interface.
3 - Por fim, configure a 3ª parte do programa de (exemplo: WXtrack) para usar a porta COM virtual (COM7).

Basicamente, o WXtrack vai enviar comandos do GS232A ao ARSVCOM sendo os comandos processados e encaminhados para a porta USB.
(Informação gentilmente cedida por Paolo).

Translation by: Eduardo Mata, thanks!

Download Icons for ISS and STS

You can download these icons, which have been contributed by WXtrack users, to show the International Space Station and Space Shuttle (ISS and STS) on your WXtrack display.  Note that the STS, Progress and Soyuz icons will need to be renamed with the NORAD catalogue number for each new launch.  Copy the contents of the zip file to your WXtrack directory.  My thanks to those who have made their work available to the WXtrack community.  These icons may not be used with software other than WXtrack without the specific permission of the icon author.  Here's a screen-shot of the registered WXtrack in full ISS display mode.

David Davidson STS & ISS icons

Screen-shot of ISS and STS icons in use.
The docked icon is in the docked 
directory in the Zip archive.

(two separate icons)

(ISS icon with docked Shuttle)
Jörg Fiegge Tiangong 1, Shuttle, Progress & Soyuz icons

Remember to rename the icons with the NORAD catalogue number before use (37820 = Tiangong 1).  Jörg lives near the home of the first German cosmonaut.

Michel Casabonne STS, TDRSS, ISS, and Sun icons

The orange Sun icon requires an icon editor to replace the MAINICON in WXtrack.exe

Screen-shot with some of these icons in use.


     (new versions)

Neville Roberts Meteor-M N2 weather satellite icons, choice of five sizes


Neville Roberts NOAA weather satellite icons



Screenshot of NOAA icons in use

  NOAA satellite icons


George Papadopoulos  icons

Includes renovated ISS (and without the STS), Progress, Soyuz, ATV and reversed shuttle, Hubble, and X38-B.  Not all shown here.

George's icons in use.






George has provided updates to his icons in June 2012.

Yorgos Papadopoulos earlier update

George Papadopoulos updated icons Dec-2015 update - including ATV, Cygnus (updated), Dragon, HTV, ISS, Tiangong and X37B
George Papadopoulos updated ISS icon ISS Dec-2015 & Oct-2016 updates

Download World Maps

For French speakers

For Spanish speakers

If you like this software, you can rate it at the DXZone web site that lists related programs.  Rate this Software @ The DXZone.  Be sure to register WXtrack and help support continued development.

A self-help group is available for this software:   here


I am very grateful to the late Ferran Alegret for providing a Spanish language version of the help file, which may be obtained directly from his Web site, and to Jean-Louis Fenasse for the French language help file and information.  Thanks to Roger Hedin for his additions of some lakes and island groups to the original Country & State boundary data.  George Ioannu provided the WXReceiver program for automatically scheduling reception.  David Bate suggested the MET display, and provides data updates. The orbit prediction code was derived from Dr T S Kelso's Pascal units on his CelesTrak web site.  Many thanks to Dr Kelso who very kindly gave permission for his code to be used.  A component that can access the SGP4 model based on Dr T S Kelso's code is available from this page.  Without Dr T S Kelso's code, WXtrack would not have been possible.



WXtrackGL Screen Shot
Click for more information

Imagine that you are flying in space, looking down upon the Earth.  All your favourite satellites are visible, and you can fly around to your heart's desires.  Oh, and it will cost you nothing!  Yes, that's WXtrackGL.

You can choose when and where, and which satellites are displayed.  You can set whether you manually control the program, or get an automated ride on the satellite!

V2.1.0 Updates the program to allow it to act as a viewer for any data presented on a world-map projection and generalises the time steps.  Make solar illumination optional, add higher-speed modes, add solar & lunar viewpoints, allow background image choice, add persistence of selected settings.
V2.1.2 Improved error messages, give folder name if no Keplers found, suggest user downloads WXtrack.
V2.2.0 Add support OpenGL 2.x systems.



NOAA-16 coverage from New York

Imagine if you could superimpose all the passes for a given satellite for a week or a month ahead.  You would end up with a plot showing the coverage from your location.  This simple program allows you to do just that, and provides a text file of the results for any further processing you wish to make.  Experimental, unsupported program.  Requires the SGP-4 component V3.2.0 listed below.  

The screen shot to the left shows the coverage to be expected from an HRPT station located in New York.  Note the differences between north-bound and south-bound coverage shown as red and blue lines.


V1.0.6 Add gnomonic projection.
V1.1.0 Build with Delphi 2009


SGP4 component - DJTSatLib.dll

Do you want to use the same prediction code as in WXtrack?  Perhaps you want to call it from Visual Basic, Visual C++, Visual C#, Java, a Web page, or even a batch file.   This component is for you!  I have made available the core SGP4 model satellite prediction routines used in WXtrack as an Active-X DLL component.  This allows you to call satellite prediction routines from any program, Web pages using ASP, or even from the command line by using the Windows Scripting Host.  Working samples are provided showing how to obtain a list of passes with Microsoft Visual Basic, Visual C#, Visual C++, Borland's Delphi, using the Windows Scripting Host and using Active Server Pages.  

As in WXtrack, the core code is from Dr T S Kelso's Pascal implementation of the highly accurate SGP4/SDP4 orbital model.  Many thanks to Dr T S Kelso for making this code available.

V3.2.0 Add access to satellite state.
2002 Apr 05 Updated Les Hamilton's VB5 demo.
2003 Jan 15 documentation update. 
V3.4.0 Add Period function and access to Kepler data, add MeanAnomaly to Kepler data, add MakePassDetails function.
2005 Feb 26 - updated Les Hamilton's VB5 demo.
2005 May 31 - added Nadir's C# demo.
2005 Jul 18 - updated Les Hamilton's VB5 demo to demonstrate the MakePassDetails function.
V3.5.0 2005 Jun 16 - fix memory leak with duplicate satellite names.
2005 Jul 17 - increase error-checking in MakePassDetails (where a direction other than N, n, S, s is specified, where the satellite name is mis-spelt).
2005 Jul 17 Les Hamilton updated the VB5 demo (V6.0 update to make use of the function 'MakePassDetails').
V3.6.0 2006-Sep-02 - add function MakePassDetails2 which includes the range rate.
2006-Sep-13 - add Java class and demo project from Henk Marais.
2007-Jan-15 - update Les Hamilton's VB5 demo.
2009-Jun-07 - restore C# demo.
2011-Mar-17 - add note about needing Administrator mode for REGSVR32 with Windows-7.
2020-Apr-29 - Add VB.Net demo from (name lost).
2020-May-05 - Added note to C# demo how to return values in degrees rather than radians - thanks: Gerhard Schweizer.

This is exactly the same core code as used in WXtrack, but is provided without support.  Scott Hather is using a version of this DLL in the current version of his SatScape software.

Note for Windows-7 users

If you are running Windows-7, you must be in Administrator mode to register the DLL with Windows.  You can get an Administrator mode command prompt as follows:

  • Start menu, All programs, Accessories, Command prompt
  • Right-click, Run as Administrator

Then navigate to the directory containing DJTSatLib.dll and enter the command:

REGSVR32 DJTSatLib.dll

If you get an 0x80004005 error message, you were not in Administrator mode.

Schedule your APT RX - PassControl

Screen shot of PassControl at work

If you have an R2FX, R2ZX, R139 or RX2 receiver, you may have wanted to control it from your computer so that important passes were collected, and not ruined by other satellites capturing the receiver.  My PassControl program allows this scheduling, and being RS232-based, it works under Windows XP, 2000, NT etc. as well as Windows 98 and ME.

This program has been fully updated for the new GEO PIC 1.0 and for Kepler data for NOAA-18 & NOAA-19.

Hardware requirements:  an R2FX, R2ZX, R139 or RX2 Receiver modified for serial remote control.

V3.1.0 Support GEO's R2FX (standard) and R2ZX (pager-proof) receivers - from the GEO Shop.
V3.2.2 Support NOAA-19.
V3.2.4 Update for proposed NOAA-18/NOAA-19 frequency swap.
V3.3.2 Update for NOAA-15/NOAA-17 frequency swap.

Please note: If you are upgrading PassControl under Windows 2000, the first time you run the program you may get an error dialog box, possibly with the message "Catastropic error". This error will go away once a valid location for the Kepler data is entered. Note that Windows 2000 is not a supported version.

Mapping Tools

Now have their own page - please click this link.

Copyright © David Taylor, Edinburgh   Last modified: 2023 Apr 11 at 08:28