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

Revision as of 00:03, 25 July 2015

Revision as of 00:03, 2 August 2015

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:I wondered about that too. It's apparently from the "The true reception time of message" section above. The comment didn't make sense to me, because I would expect the reception time to depend on the satellite from which the message was received. [[User:Kendall-K1|Kendall-K1]] ([[User talk:Kendall-K1|talk]]) 18:04, 24 June 2015 (UTC)

== Yet another leap second ==

I recommend editing the timescale section to reflect that the GPS-UTC offset is now 17 seconds, as of the leap second added at the end of June 2015. I would have done it myself except that the page is locked. Reference: http://www.navcen.uscg.gov/?pageName=currentNanus&format=txt [[User:Karn]] [[User:Karn|Karn]] ([[User talk:Karn|talk]]) 08:38, 1 July 2015 (UTC)

=== Protected edit request on 1 July 2015 ===

{{edit protected|Global Positioning System|answered=y}}

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"As of July 2012, GPS time is 16 seconds ahead of UTC because of the leap second added to UTC June 30, 2012." should be changed to be "As of July 2015, GPS time is 17 seconds ahead of UTC because of the leap second added to UTC June 30, 2015." (Reference 144 is no longer directly applicable to the 17 seconds, but reference 144 plus https://en.wikipedia.org/wiki/Leap_second showing the July 30, 2015 leap second addition gives the total.)

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[[Special:Contributions/67.135.185.226|67.135.185.226]] ([[User talk:67.135.185.226|talk]]) 14:59, 1 July 2015 (UTC)

:{{done}} &mdash;&nbsp;Martin <small>([[User:MSGJ|MSGJ]]&nbsp;·&nbsp;[[User talk:MSGJ|talk]])</small> 10:25, 2 July 2015 (UTC)

== Trilateration Not Triangulation ==

I believe there is a minor error in this sentence: "The U.S. Federal Communications Commission (FCC) mandated the feature in either the handset or in the towers (for use in triangulation) in 2002 so emergency services could locate 911 callers."

As with the GPS ranging system the cell tower ranging is based on distances not angles. Would that not make it "(for use in trilateration)"?

[[User:TafThorne|TafThorne]] ([[User talk:TafThorne|talk]]) 10:17, 1 July 2015 (UTC)

:It's unclear what "the feature" means in that sentence. Are they talking about geolocation or time synchronization? [[User:Kendall-K1|Kendall-K1]] ([[User talk:Kendall-K1|talk]]) 12:22, 1 July 2015 (UTC)

::If that's a direct quotation, it could be rewritten as "for use in triangulation (sic, trilateration)". I doubt the FCC cares to know the difference between the two methods. [[User:Fgnievinski|Fgnievinski]] ([[User talk:Fgnievinski|talk]]) 04:51, 2 July 2015 (UTC)

:::The usage above is consistent with the definition at http://www.oxforddictionaries.com/definition/english/triangulation, which specifically mentions GPS in its example sentences. One of the sources used in [[Trilateration]] has [http://www.diracdelta.co.uk/science/source/t/r/triangulation/source.html this] definition for triangulation, which includes ranging based on distances ''or'' angles. [[User:Burninthruthesky|Burninthruthesky]] ([[User talk:Burninthruthesky|talk]]) 10:07, 2 July 2015 (UTC)

::::So, instead of moving [[Triangulation]] over [[Triangulation (surveying)]] (which remains the primary topic), I propose to create a new [[Triangulation (mobile technology)]] which redirects to [[Mobile phone tracking]], and make a note in [[Triangulation (disambiguation)]]. [[User:Fgnievinski|Fgnievinski]] ([[User talk:Fgnievinski|talk]]) 18:28, 2 July 2015 (UTC)