Contents
- Index
Stale Satellite Orbit Data
WXtrack monitors the age of the individual satellite data as it is read line-by-line from the data files. If duplicate entries are found for a particular satellite, the data with the most recent epoch will be used. General opinion is that this data should be considered stale as far as making accurate predictions is concerned after about two months so, when no parameters have been specified, WXtrack will check the satellite data after any duplicates have been eliminated to ensure that all entries are less than 40 days old. If not, a warning message will be issued. If you are using HRPT, you may conside Keplers more than one week old as stale.
I got the "Satellite Data is Stale" warning message - what should I do?
You should check which data is stale using the View, Satellite data... menu. It may be that:
there is an old data file that should have been deleted, or
the satellite data folder isn't where you thought it was, or
it's been a little while since you downloaded new data.
You have three choices:
To ignore the age of the data and continue
To update the Keplers over the Internet
To use Manual Kepler Update
The program will continue with the existing data once you acknowledge the dialog.
Manual Kepler Update
Using Internet Explorer, this is what you can do:
Go to the Celestrak Web site http://www.celestrak.com/NORAD/elements/
View the files you want, e.g. noaa.txt, amateur.txt, weather.txt by entering the appropriate URL in the browser. e.g.
http://www.celestrak.com/NORAD/elements/noaa.txt
Save the files from within the browser
Replace noaa.txt etc. in your WXtrack Kepler folder with the ones you saved.
As a check, you can view the files using notepad, as they are just text files. As you gain confidence, you can speed the process by:
going to the page: http://www.celestrak.com/NORAD/elements/
right-clicking "Weather", "Amateur Radio" etc.
choosing the "Save Target As..." from your browser's pop-up menu
saving directly to the WXtrack Kepler file location.