Googlemaps co-ordinates query

[+duckson]

If i punch in the Geocache co-ordinates in on Googlemaps it comes back with 2 locations - one with an "A" and one with a green arrow. Can someone explain what the difference is?

eg

http://maps.google.co.uk/maps?q=N+57%C2%B0+33.220+W+002%C2%B0+32.409&um=1&ie=UTF-8&sa=N&hl=en&tab=wl

 

I travelled a few miles by car to the co-ordinates i put into the Googlemaps app on my Android phone (HTC Desire) but it took me to the "A" location which is a long way from the actual Geocache location at the green arrow!

 

Any ideas why?

[+Sir-Lancelot]

Hey,

 

I was always led to believe that the red arrow was the position on the nearest road whilst the green arrow was where the cache was actually located. But it seems in this case it has decided that the nearest road is the B Road and not the road that the cache is practically on, Maybe the road the cache is on is a private road, or maybe you have just uncovered a blip in Google maps.

 

Joe

[+MrCJDL]

Yeah, the red 'A' marker always points to the nearest road... but I think it only includes 'major' roads, e.g. M, A, or B roads. Minor / track roads although on the map never seem to get 'marked'.

 

BTW, how accurate is google maps for coords ? I've heard some people say it's fine and others say it's wildly inaccurate. Does it depend on location ? I use it to double check my coords, and adjust slightly if necessary when placing caches - and nobody ever seems to have had a problem finding them...

 

As a sidenote, I'd say that blindly following GPS/satnav is never a good idea... always sanity check it against where you actually want to be :-)

 

HTH.

Edited July 27, 2011 by cjdl

[+Bear and Ragged]

BTW, how accurate is google maps for coords ? I've heard some people say it's fine and others say it's wildly inaccurate. Does it depend on location ? I use it to double check my coords, and adjust slightly if necessary when placing caches - and nobody ever seems to have had a problem finding them...

Don't rely on the maps and satellite photos.

The amount of 'Off' varies, and is not consistent.

 

Hence Groundspeaks Guidelines saying use a GPS to get the coordinates when setting a cache.

Maps are good to see the coordinates you have entered in to the cache page are in 'the general area' of the cache.

Edited July 27, 2011 by Bear and Ragged

[+stanolli]

I have seen some posted examples of where Google aerial maps are a long way out, but nearly all my finds have been with Google maps.

My experience is that the road map can be wildly out (in Chile the main highway was shown offshore), but the aerial view had always taken me within a few feet of GZ (where landmarks make it possible to determine this).

On my Blackberry I only get the nearest road location unless I type 'loc: ' before the coordinates.

[+MrCJDL]

BTW, how accurate is google maps for coords ? I've heard some people say it's fine and others say it's wildly inaccurate. Does it depend on location ? I use it to double check my coords, and adjust slightly if necessary when placing caches - and nobody ever seems to have had a problem finding them...

Don't rely on the maps and satellite photos.

The amount of 'Off' varies, and is not consistent.

 

Hence Groundspeaks Guidelines saying use a GPS to get the coordinates when setting a cache.

Maps are good to see the coordinates you have entered in to the cache page are in 'the general area' of the cache.

 

I don't, sorry should have made that clearer... I take averaged GPS readings, then double check / sanity check them on GM... I normally only need to adjust them a tenth or a few hundredths of a " I normally make a note of any landmarks, and that's what I'm sanity checking against.

[+Bear and Ragged]

The cache is not in the middle of the road, as indicated by the satellite image!

The cache coordinates are good.

(Not my cache)

 

 

But, if it was my cache and I saw that image, I'd be happy enough with my coordinates.

Edited July 27, 2011 by Bear and Ragged

[+luvvinbird]

I know people will argue with me, but I use Google Earth to get an overview of the cache location and I've found it to be very accurate. In fact, I've yet to notice any appreciable inaccuracies.

[+YooperSnowman]

Is the accuracy/resolution of Google Maps and Google Earth higher in urban areas than rural areas? Do the map makers put a higher priority on areas with higher population density? Is data storage an issue and therefore less information provided for remote areas?

[+dfx]

I know people will argue with me, but I use Google Earth to get an overview of the cache location and I've found it to be very accurate. In fact, I've yet to notice any appreciable inaccuracies.

They're most easily noticeable where tiles have been stitched together: http://maps.google.c...011169&t=h&z=17 - http://maps.google.c...011169&t=h&z=17

 

Is the accuracy/resolution of Google Maps and Google Earth higher in urban areas than rural areas? Do the map makers put a higher priority on areas with higher population density? Is data storage an issue and therefore less information provided for remote areas?

Generally speaking yes, except for the last part (it's not a storage issue). However it's not a guarantee, even urban areas can have misaligned imagery.

Edited July 27, 2011 by dfx

[+duckson]

Thanks for the replies.

 

Yes looks like that is the nearest A or B road to the actual location. This cache is on a public road (i'm near and been to it) but its a minor road and i cant see an actual specific road number eg B**** on Googlemaps at least.

 

Likewise this one is just a few yards off the nearest A / B road.

 

http://maps.google.co.uk/maps?q=57.5378+-2.65802&um=1&ie=UTF-8&sa=N&hl=en&tab=wl

Edited July 27, 2011 by duckson

[+dfx]

If you want to get rid of the double marker, use one of the following formats:

 

http://maps.google.c...7.5378+-2.65802

http://maps.google.c...7.5378+-2.65802

http://maps.google.c...802+%28cache%29