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View Full Version : Satellite tracking........



arthurking83
8th January 2006, 08:02 AM
I found heaps of sites (well 2 really :o ) on tracking satellites in realtime, NASA (http://science.nasa.gov/realtime/) seems the most feature rich of the two main sites I found, with the interactive java applet.

I did find some software a while back, for predicting the sun/moon/stars/satellites, positions, but couldn't figure it out ????
Satellite Tracker (http://www.heavenscape.com/)

But if you're interested in tracking satellites in you region, the NASA site makes it easy.

Heavens Above (http://www.heavens-above.com/Logon.asp?Err=SessionExpiry)(easy, painless registration) is the other site, and it will predict an Iridium satellite flare for your location!

Interesting stuff, but not essential to the operation of your GPSr :D

arthurking83
12th January 2006, 10:20 PM
I've been at it again :rolleyes:

More garbage(!!) to install onto your computer(if you dare!!)

I've been playing with a nifty program called Satellite Tracking GPS (http://www.movingsatellites.com/) .
This program uses almanac data to graphically show you what the current predicted satellite positions are.
As the positions of the satellites has to be adjusted or not repectly predicted, the almanac is updated daily, and available from various sources.

If you download the 14Meg file (choose the gps24all.zip file) it doesn't install itself, you just extract and run from a folder of your choice.
Execute the gps.exe, and the program runs, but with 2003 data.
So you need to update the data required to see satellite positioning.

Celestrack (http://celestrak.com/NORAD/elements/) is one option to get various satellite almanac data, and it's in the correct .tle format, but in a .txt file.
Right click a file and "save as" (all file types) and rename ***.tle.
It's best to save the file into the same folder as you unzipped gps24.
(but not essential!)

navcen.uscg (http://www.navcen.uscg.gov/ftp/GPS/almanacs/yuma/) has a better almanac file.
Download the latest(date) yuma***.txt file and this needs to be converted to a .tle file.
This is easily done with alm2tle (http://www.geocities.com/kiwi_36_nz/alm2tle/alm2tle.htm), again, just unzip and run the alt2tle exe.
Use this to convert the yuma***.txt file into a GPS.tle file readable by gps24.
Place the Yuma***.txt file into the same folder as alm2tle, and run the alm2tle exe, type in the number of the yuma file, *** (which is the week of the GPS system's operation!) and [Enter].
There will be a file called GPS.tle in the same folder, use this file in gps24.
The reason this almanac file is better is that the Sat numbers are closer to the PRN numbers Magellan users see on the GPSr (Sorry Garmin users, I don't know how to fix?). There may be one sat number to PRN number adjustment, which will make the numbers askew, (eg Sat12->PRN13....), but this is easy to understand.

Now with Satellite Simulation(GPS24) running just open a .tle file (the one alm2tle called GPS.tle (in the alm2tle folder??) and most likely Satellite #1 will be shown.
You can enable and disable the Sat numbers using the "toolbar" buttons!
Before you do, and clutter up the screen!!! bottom right corner, is the time skip slider.......slide forward to accelerate the sats position and watch the animation
Fill the screen with the Sats and .......... :eek:

From the celestrack site there are other sats you can watch, try the Space Station, just download the txt file, but save to tle filetype (no need to convert it just change the extension)

One interesting use for this software, is you can track the Irridium satellites, and possibly predict the position of the flares these sats produce!
So you can impress your (geeky?) mates and tell them "hey at 9:49PM, theres going to be a short flare over there........!"
( I haven't seen that from gps24 (just a guess), but there are other programs to do that!)

To configure your position in gps24, just use the toolbar "ViewWDB" and choose "Go To..." Melb, Syd....etc are in the list. If you are far out of town, just use your GPS position (in degree decimal format, DDD.DDDDD)

The animations are cool (5 year olds love it) and having precise satellite constellation data to verify that your Magellan Color GPSr is playing up every now and then :rolleyes: ......... *ranting and raving... off*

Here are some screenshots........
first pic is with just 4 sats enabled on screen, to unclutter the pic, second image is the spacestation tracking.

Hope you guys get as much enjoyment from it!

Oh! like I said before, there are other(a zillion) programs to do this, it's just one of the better ones