Categories: Fix a problem or issue : Street View and Satellite Imagery : Windows : Chrome :

How accurate is the Lat/Lng that you get from SV API's getPosition()?

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How accurate is the Lat/Lng that you get from SV API's getPosition()? Kotaro Hara 3/26/13 9:17 AM
Hi all,

I am using Street View Service to develop my application that is similar to this example. In this application, I want to store where, in lat/lng coordinates, users have traveled on the map. I figured out StreetViewPanorama class provides an API, getPosition(), and this returns LatLng. Lat/lng coordinates you extract from LatLng object look like lat=38.924066 and lng=-77.032172. I can use these values to store what I want.

Although the aforementioned latlng values have 8 significant figures, I was actually wondering how accurate these values are, because GPS locations that Google collects while running a Street View car would have errors. My question is, how accurate is the latlng value returned by getPosition()? In other words, how much concordance can I expect between latlng values from getPosition() and latlng position on Google Map?

Thank you very much!
Kotaro


Re: How accurate is the Lat/Lng that you get from SV API's getPosition()? barryhunter 3/26/13 10:17 AM
A 6dp lat/long is on the order of precise to 0.1m. (ie 10cm) 

So such a lat/long should match up very precisely with the Google Map. Ie its a precise location. 


But as to how accurate the underlying map is, that varies a lot. Its almost impossible to tell. Most locations I would estimate to be within about 6-30m 



Re: How accurate is the Lat/Lng that you get from SV API's getPosition()? Kotaro Hara 3/26/13 11:12 AM
Hi Barryhunter,

Thank you so much for your response!

A 6dp lat/long is on the order of precise to 0.1m. (ie 10cm) 
Do you have source for this? It would be a great help if you do.

But as to how accurate the underlying map is, that varies a lot. Its almost impossible to tell. Most locations I would estimate to be within about 6-30m 
Great point. I was wondering how accurate the Google Map is in the first place (or rather what would be the ground truth.)

Thank you very much for the information!

Kotaro
Re: How accurate is the Lat/Lng that you get from SV API's getPosition()? barryhunter 3/26/13 11:39 AM
http://nearby.org.uk/precision-ll.cgi?lat=38.924066&long=-77.032172

:)

I didnt quote the exact figure, because the actual numbers vary with latitude (which is why it actully asks for coordinates) - just a general figure. 


(disclosure, I made the above page!) 
Re: How accurate is the Lat/Lng that you get from SV API's getPosition()? Kotaro Hara 3/28/13 9:56 AM
Great! Thank you Barryhunter :)