GPS Accuracy Data for Android phones I'm try to gather data on the feasibility of my next Android project in which I would like to use GPS indoors.  Knowing that GPS wasn't built to be accurate indoors, I'm trying to decide if the project is worthwhile.

I have a rough estimate of my required accuracy (10 meters).  The location is the middle of a major city.

So I'm wondering if there is any data out there that relates to the GPS systems on Android phones that would help me with this research.

Thanks.

Edit:

Thanks for the answers so far folks.  Good reads.  I realized that there are a lot of factors affecting GPS data.  Even though I may be "shooting for the moon" with my accuracy requirements, I'm hoping that my unique situation might help achieve my goal indoors.

I intended to use GPS + wireless network data (Assisted GPS) and try to get the best accuracy possible.  My user will also be in the middle of a major city, which I would imagine would have many cell towers.  Whether or not I can achieve this with current/up-and-coming Android technology is really what I would like to determine, so my search for actual data representing valid tests of Android devices continues.

If you have any links to data of this sort, please do share.

Thanks again all!
10 m?  You'd be lucky to get that kind of accuracy outdoors.

I'm the developer of Car Dashboard, which is a car home replacement that includes GPS features like speedometer, etc. I have the default minimum GPS accuracy set to 200 m which seems to work pretty good for most users (I also have it adjustable in the settings in case they have issues).  On average, I'd say indoors near a window will get you about 50-100 m accuracy. Outside with nice conditions should get you below 50 m. Indoors without any visual sight to the sky is going to be a dead zone.  The signal is just simply not going to reach you and if it does, it is going to be highly inaccurate. 

This is the resource I use to describe GPS accuracy in my application: 


  GPS accuracy is affected by a number
  of factors, including satellite
  positions, noise in the radio signal,
  atmospheric conditions, and natural
  barriers to the signal. Noise can
  create an error between 1 to 10 meters
  and results from static or
  interference from something near the
  receiver or something on the same
  frequency. Objects such a mountains or
  buildings between the satellite and
  the receiver can also produce error,
  sometimes up to 30 meters. The most
  accurate determination of position
  occurs when the satellite and receiver
  have a clear view of each other and no
  other objects interfere.