Tag Archives: featured

Real time trajectory in Google Earth

Google Earth allows you to display coordinates saved into a kml file. Even better you can choose the refresh rate on GE so that you can see your path in real time. This is useful for GPS data tracking or even just for fun.

Google Earth Real Time Trajectory
Google Earth Real Time Trajectory
Here are the steps to show a path in real time on Google Earth:
  1. Go to “Add” -> “Network link”
  2. Browse the kml file you want to lead. Here is an example: GPS-Dolphin.kml.
  3. Go to the “Refresh” tab and choose your refresh rate. This will load the file at every x-seconds you choose.
  4. now just make your software update the file as frequently as you want … or for basic testing just open the KML file in some text editor and change the coordinates to see what happens.

Have fun!

Satellite Tracker

Tracking satellites can be fun (where is the ISS now?) … and complicated. Fortunately there are some algorithms that can help like the SGP4.

I’ve used an available php implementation of the SGP4 algorithm and made a simple satellite tracker application showing the ISS, but really it can show any satellite as long I feed the proper Two Line Element from CelesTrack.

Check the link and you’ll see where the ISS is hovering now: www.spacemig.com/satellite-tracker


Satellite Tracker

And you can check how accurate this is by going to this link:



  • http://en.wikipedia.org/wiki/Simplified_perturbations_models
  • http://en.wikipedia.org/wiki/Two-line_element_set
  • http://www.celestrak.com/NORAD/elements/