View Single Post
Old 9th Jun 2013, 10:22
  #1 (permalink)  
Spir4
 
Join Date: Mar 2013
Location: Belgium, Ostend
Age: 32
Posts: 17
GPS: what does a satellite send out?

Hello,

A GPS satellite sends out ephemeris and almanac data, on that subjects all sources I've read agree.
But it's about the health data, the ionospheric delays, and the offset of satellite clock from GMT that a lot of books disagree.

I asume health data is being transmitted by the satellite.
The ionospheric delay can only be corrected by differential GPS or by comparing the L1 and L2 signal. So it isn't send out by the satellite. How would a satellite even know what that delay is?
And the receiver receives the satellite's clock, and corrects its own internal clock to match that satellite's clock. Otherwise the correction to the receiver's internal clock would become bigger and bigger over time.

Am I right about those items?

Last edited by Spir4; 9th Jun 2013 at 10:23.
Spir4 is offline