Prime Meridian Greenwich off 200 meters with GPS?

[tiagotrinidad]

Your GPS is almost correct. Greenwich is on 0º 0.089' on the WGS reference system (the one used by GPSs). Look up "World Geodetic System" on Wikipedia :)

[speedyduck38]

The line is correct. Just because your bullshit gps says different doesn't make it wrong.

[lesorciercalifornien]

The reference system that is used now (called WGS-84) is different from what it was in 1884 when the prime meridian was defined for the first time.

[JJtoob]

Yes, Wikipedia. You are welcome. I'll summarize: Prime Meridian cannot be a constant due to shifts in earth's rotation (movement of the ocean is slowing it down and then the 2010 earthquake in Chile accelerated it again), shift in tectonic plates, an old satellite system that was designed for the US and further complicated by more bases around the world. That's why your GPS instructions usually will tell you not to blindly trust its accuracy.

[JoaoSuperCarros]

lool

[foxdmulder]

Want to know if your gps is 100% accurate (even though they never will be) walk to a cross roads and see if your 150 degrees off. Personally I think that you are depending on too much technology. Im going to stick to the greenwich Observatory as being the prime meridian.

[KnickerBocker39]

Planning to go here next month while I'm London. Is it hard to find? Can the tube or trains from London get you there?

[neil9327]

All true. The GPS definition of the meridian is around 100 meters to the east of the Grenwich-defined one.

I took a walk the same as you did, but a bit to the south, and found myself in a car park at the top of the hill.

Maybe I'll go there with some white paint one night and draw the -proper- line for it ;-)

[RAJADURADPLACARD]

most important, is that meridian is an arbitrary line created by human with the purpose of mark the hours around the world taking a place like reference. and gps always indicates that the real position might be different for few metters. EL MERIDIANO FUE CREAOD ARBITRARIAMENTE EN UN LUGAR PARA MARCAR LAS HORAS ALREDEDOR DEL MUNDO LA UNICA GRACIA SERIA ESTAR EN EL EQUINOCCIO (21 MAR-SEP) Y VER QUE TU RELOJ DE LAS 12 Y ESTE EL SOL SOBRE TI CON RESPECTO A ESTE Y OESTE. EL GPS METETELO EN EL CULO

[ednuttah]

You paid nothing to get into the Prime Meridain museum, and you paid for that phone? You could always get a better phone or argue the case with accurist, swiss clock makers of the Prime Meridain. Up to you.

[djschumi8]

Its funny how much people believe in their GPS system!! Did u really think that you would get 100% accuracy free of charge?

[malproxy]

According to Wikipeida:

Prime Meridian is defined by the WGS84 system as about 100 metres to the east.

[jlecomte0719]

This discrepancy is due to the non uniformity of the Earth rotation (difference between UT1 and UTC) The Greenwich meridian is indeed mobile!

[simonjp80]

The GPS system is controlled by the American Government - they provide it to us punters for free, but on the condition that they will occasionally screw with the signal in this way. It's so their enemies can't use their own tools against them.

[CProgression]

I can hear the villian on Scooby Doo saying, "Yeah and I would have pulled it off too, if it weren't for you meddling kids" This dude must be right... so my heading to Greenwich to move the line would be a waste of time since the American Gov't is probably "screwing with the signal". Thanks for saving me the airfare!

[fraud1958]

I can hear the Parisians snickering.

[aetu5]

the zero meridian of the gps cooridinates is not the same as the greenwich prime meridian system. the offset is around 120 m.

[VaguelySimilar]

That is because GPS is inaccurate to around 250 yards. Accept, that is, really good GPS, not the kind you get in a mobile phone!

[wytsep]

It's a conspiracy!