GNSS Propagator

1

Hi folks,

I have been having a play with the GNSS propagators today and had a couple of questions. I have loaded in data from a Galileo nav file and used that to initialise a GNSS propagator which I have then used to do the propagation in the normal manner. Comparing the results of the propagation to later nav file positions shows that the GNSS propagator actually performs remarkably well, in my opinion, for minimising error - I typically see position errors around 1m over short (~2 hour) timescales. I went to have a look at the algorithm to see what it was doing but could not find a name anywhere, does it have a name? Is there a paper that explains the corrections to the standard Keplerian motion etc? Secondly, if I wanted to get as precise an orbit solution as possible for the GNSS constellation between nav file epochs, is it worth me using a full numerical propagator to do this and if so are there standard CSAs/masses available for the constellations?

Thanks for the help!
/Paul

2

You can have a look at GPS and Galileo Satellite Coordinates Computation page in navipedia.

If you want better data than the broadcast ephemerides, you must either determine the orbits and clocks of the full constellation by yourself (a difficult task) or get corrections from the High Accuracy Service (HAS), but you will have to wait until this is available (a few years)