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Talk:Theory of relativity (view source)
Revision as of 21:51, December 7, 2014
, 21:51, December 7, 2014→GPS and Relativity
:::Roland, your good edits are appreciated and I've seen no complaints about them. I agree that the [[Context-Free Grammar]] would benefit from a better introduction and look forward to reading what you add there.--[[User:Aschlafly|Andy Schlafly]] 17:39, 9 April 2012 (EDT)
:::Roland, your good edits are appreciated and I've seen no complaints about them. I agree that the [[Context-Free Grammar]] would benefit from a better introduction and look forward to reading what you add there.--[[User:Aschlafly|Andy Schlafly]] 17:39, 9 April 2012 (EDT)
===READ THE MANUAL===
This debate seems pretty ridiculous, given that GPS is a public system with open specifications. If you're building a GPS receiver you do, in fact, need to compensate for relativistic effects. The correction equations that must be used on the receiving side equipment are given in the official GPS interface specification, IS-GPS-200G [http://www.gps.gov/technical/icwg/IS-GPS-200G.pdf], p.92. section 20.3.3.3.3.1: User Algorithm for SV Clock Correction.
<blockquote>
The polynomial defined in the
following allows the user to determine the effective SV PRN code phase offset referenced to the
phase center of the antennas with respect to GPS system time (t) at the time of data
transmission. The coefficients transmitted in subframe 1 describe the offset apparent to the two frequency
user for the interval of time in which the parameters are transmitted. This estimated
correction accounts for the deterministic SV clock error characteristics of bias, drift and aging, as
well as for the SV implementation characteristics of group delay bias and mean differential
group delay. '''Since these coefficients do not include corrections for relativistic effects, the user's equipment must determine the requisite relativistic correction. Accordingly, the offset given below includes a term to perform this function'''...
</blockquote>
I did not include the equations here, but they're given in the manual.
== Why are adjustments needed to GPS? ==
== Why are adjustments needed to GPS? ==