Talk:Global Positioning System/Archive 8: Difference between revisions

Revision as of 00:06, 22 May 2015

Revision as of 06:35, 19 June 2015

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I changed the wording of the new redirects from "European GPS" to "European equivalent" (and same for GLONASS). Although it's in quotes, I think it's too confusing if we call Galileo by the colloquial name "European GPS". I'm also not sure we need these redirs. We could change the hatnote to something like "This article is about the US satnav system" and add Galileo and GLONASS to the disambiguation page. [[User:Kendall-K1|Kendall-K1]] ([[User talk:Kendall-K1|talk]]) 13:30, 20 April 2015 (UTC)

==Geometric interpretation sections is misleading and poorly written==

I don't know who wrote it, but the section called, Geometric interpretation is rather misleading and appears to be poorly written. First of all it talks about Hyperboloids. But it is not equations for hyperboloids that are solved. Then it is stated that the solutions space is a spherical cone in 4 dimensional space. But the solution space is just a single point, [x, y, z, b].

To make matters worse, the writer of this section fails to point out that the equations to be solved (i.e. find the intersections) are the equations for the surfaces of four or more spheres in three dimensional space. This section can be expected to greatly confuse the reader making it more difficult for the reader to understand how GPS works. [[User:RHB100|RHB100]] ([[User talk:RHB100|talk]]) 01:17, 5 March 2015 (UTC)

*{{ping|RHB100}} Would you please clarify what is the new issue compared to the previous discussion, as settled in [[Talk:Global Positioning System/Archive 7#Solution based on intersection of at least four spheres, not TDOA and not Multilateration]] and [[Talk:Global Positioning System/Archive 8]]. [[User:Fgnievinski|Fgnievinski]] ([[User talk:Fgnievinski|talk]]) 19:40, 27 April 2015 (UTC)

== Fix this sentence ==

I can't quite figure out what this is trying to say. Can someone fix it please? [[User:Kendall-K1|Kendall-K1]] ([[User talk:Kendall-K1|talk]]) 12:52, 23 February 2015 (UTC)

*Both the equattion four four satellites or the least squares equations dfor more than four, are non-linear and need special solution methods. A common approach is by iteration on a linearized form of the euations, (e.g., [[Gauss–Newton algorithm]]).

**Ranging involves the receiver coordinates in a non-linear expression: R = sqrt(DX^2+DY^2+DZ^2), where DX = X_rec - X_sat. To invert four of more measurements for the unknown coordinates, we solve instead a simplified linear approximation, given by the partial derivatives: dR/dX_rec = DX/R, etc. [[User:Fgnievinski|Fgnievinski]] ([[User talk:Fgnievinski|talk]]) 20:24, 27 April 2015 (UTC)