Kepler Updater
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The Kepler Updater

What is the Kepler Updater?

The Kepler Updater allows you to interface with the CelesTrak Web site to download two-line element data.  You can also use the automation features of the Kepler Updater to keep your Kepler data current for both the multi-line Kepler data required by real-time tracking programs such as WXtrack and the historic Kepler data required by programs like the HRPT Reader for processing non real-time data.



  1. Download the Zip file, and right-click, Properties, Unblock it.
  2. Extract the contents of the Zip file to a directory of your choice.
  3. Recommended directory:  C:\Tools\SatSignal\KeplerUpdater\
  4. If you don't already have my runtime Library, get it here.
  5. Follow the setup instructions below.


As far as possible, any setting you already have for the earlier Kepler Manager software will be entered as defaults in the Kepler Updater on its first run.

  • Groups

In the groups list, check the groups you wish to download from CelesTrak.  If there's a group missing which you feel is important, please let me know.  Data will be saved to a folder of your choice such as C:\Tools\SatSignal\WXtrack\  You can use the [...] button to browse for another directory.

  • Favourites

For your own selection of satellite data, enter the NORAD numbers into the My Favourites list.  Enter a file name (within the groups folder) where the data should be saved.

  • Historic data

The program will update any historic Kepler data you have in the "historic Kepler data" directory.  All files named *.txt will be checked and updated from either the EUMETSAT Web site if those satellites are available, or from the CelesTrak Active List otherwise.  Note that if the satellite is not on the Active List, it will not be updated, so data for e.g. Envisat and FY-1C will not be updated.  Enter the path to the Historic Kepler data, for example: C:\Tools\SatSignal\HRPTreader\keps\updates\.

Starting Historic data

To add new historic data, for each new satellite you need to create a plain text file using Notepad, named e.g. Metop-C.txt, in the Historic directory to "seed" the program into updating the data.  The program must contain at least two sets of two-line Kepler entries, although they can be the same entry duplicated as show below.  These two entries are needed:

  • to tell the program which the satellite is - it uses the NORAD number not the file name
  • to see at least two identical entries for the same satellite so that it knows it's a multi-date file, and not a multi-satellite (group) file.

You can get a suitable entry from one of the other group files such as weather.txt.

Metop-C.txt - sample starter file for Metop-C data
1 43689U 18087A   19208.35922370  .00000000  00000+0  18863-4 0 00018
2 43689  98.7019 267.4644 0002212 182.0628 259.0639 14.21491212 37273
1 43689U 18087A   19208.35922370  .00000000  00000+0  18863-4 0 00018
2 43689  98.7019 267.4644 0002212 182.0628 259.0639 14.21491212 37273

Getting the most recent data

Click the Run button, or execute the program from a command script with the -AUTO parameter.

If necessary, you may need to allow the program access to the Internet using your PC's firewall software.

Note that to avoid excessive load on CelesTrak new data will only be loaded after couple of hours since it was previously downloaded.

A log file will be left in the Groups directory named  KeplerUpdate.log  showing the results of the last run.

Dial-up is not supported, nor Internet connections which require a proxy login.

Regular running

Use the Control Panel, Task Scheduler to run the program at a suitable time, possibly as part of your overnight tasks.  I run the program as part of a command script which gets the Kepler data and shares it with other PCs.


  • You must be running Windows -7 or later.  Older Windows versions may not work and are no longer supported.

Download the Kepler Updater

V2019.07.28.04     First released version.
V2019.07.28.05     Add WXtrack compatibility.
V2019.07.29.06     Include SSL libraries in the archive.
V2019.07.30.07     Honour user's group selection.
V2019.08.29.08     Add Science and Stations groups.
V2020.02.23.09 Provide an option to use EUMETSAT data or not.
V2020.05.14.10 Revert to HTTP access following CelesTrak changes.
V2020.11.20.11 Update for EUMETSAT Web site changes.
V2020.12.02.12 Add Resource group.
V2021.07.21.13 Handle HTTPS errors when connecting to EUMETSAT site.
V2021.08.02.14 Use CURL to overcome HTTPS errors.
V2022.05.18.15 Add Iridium group.
V2022.07.04.16 New URL


The user of the program is responsible for ensuring the accuracy of any data produced by the program.

Data downloaded by the program may  not be passed onto any third party without the appropriate permissions.

Use of this program in a for-profit environment or by any commercial or industrial organisation, or by a National Institution (e.g. National Weather Service) requires registration. You can register my WXtrack software here.


This program is provided "as is" and without any warranty as to merchantability or fitness for a particular purpose or any other warranties either expressed or implied. The author will not be liable for data loss, damages, loss of profits or any other kind of loss while using or misusing this software.

This software may not be used in safety-critical or life-critical systems.

Recent problems with multi-entry Keplers

Unfortunately, the Kepler data from CelesTrak (as sent from it source) sometimes contains inconsistent, out-of-sequence orbit numbers which can confuse software including my own AVHRR Manager program.  To ameliorate this issue, the program will first get the Kepler data direct from EUMETSAT for the satellites for which they disseminate data.


My thanks to Thorsten Miglus (on Twitter) for drawing my attention to the EUMETSAT Kepler data, and for providing a super command-script for using this data, and to Dr. T. S. Kelso for discussions about the famous CelesTrak Web site and how to best use data from that site without overloading it!

Copyright © David Taylor, Edinburgh   Last modified: 2022 Jul 04 at 05:34