I am not defending the mainstream approach to GPS signals. I'm simply explaining how they explain it. There is more than one relativity adjustment. Yes, there is the relativity adjustment to the clock rate after launch. But there are also other adjustments due the eccentricity of the satellite's orbit (if any) and to compensate for various environmental factors, such as the difference in gravitational field over the surface of the Earth. The adjustments can be made either at the satellite or in the receiver. Again, I am not saying that I think these adjustments are necessary, I'm just saying that the relativists use these arguments to support relativity.Aardwolf wrote:I'm struggling to follow what you are saying. Receivers do not make any corrections to the signals received. The metadata and modelling required would be over the top compared to the gain in accuracy received. Receivers just make multilateral calculations based on the 6 or 7 signals received. The only relativity adjustment ever considered in the GPS system was the one-off frequency clock changes of the atomic clocks, pre-launch, which I had already pointed out are pointless.
Like you, I also pointed out the pointless nature of the relativity measurements in light of two facts, one the ionospheric disturbance greatly exceeds the relativity adjustment, and two, the satellites are not even dependent upon the onboard clocks as much as they are on the targeting points on the ground and the stars. The real clock of the GPS system is therefore the satellite's orbit, not the clock inside the satellite. The clock inside the satellite functions more like a metronome than an actual time reference. The real time reference is the time it takes for the GPS constellation to return to a place over specific ground targets relative to the star positions.
I did not say nor imply that anybody pretends the ionospheric adjustments are relativity effects. I said the magnitude of the ionospheric adjustments, which are highly irregular and have a random appearance, are far greater than the magnitude of the relativity adjustments. It's like trying to record the ripples of a stone falling in the ocean during the middle of a hurricane. There is no way to tell with certainty which ripples belong to the stone, and which to the hurricane. Similarly, there is no way to tell if relativistic corrections are needed when the ionospheric corrections are orders of magnitude greater.Aardwolf wrote:There are many errors associated with the signals including the ionospheric errors which I agree can be large. But the standard modelling cannot account for short term significant errors, caused by say sunspots. I don't think anyone tries to pretend that these errors are anything to do with relativity though.
Just a simple search of the Internet. Here is an example:Aardwolf wrote:Where do you get your information regarding this relativistic adjustment/correction?
http://www.phys.lsu.edu/mog/mog9/node9.html
I have read many different papers on NASA related web sites over the years, as I am sure you have.