[Discuss] GPS feature in cellphones?

[Richard Pieri]

On 7/10/2014 7:33 PM, Tom Metro wrote:
>   The bad results are largely because "[t]he location technology
>   currently used by most wireless carriers (called A-GPS) depends on a
>   direct line-of-sight to satellites, so it often fails in indoor
>   locations or dense urban areas like the District," Find Me 911 said.

Cell tower triangulation (the "A" in Assisted GPS) can be accurate to
within ~3 meters, compared to the ~1 meter accuracy of satellite GPS,
and is in fact most accurate in densely built urban areas due to the
high density of cell stations. Any carrier that claims they can't get
sub-300 meter accuracy in a major American city either installed
substandard (by E-911 standards) equipment and software or is lying
about their location capabilities.

-- 
Rich P.