this article is a little misleading...
from all accounts i have read, the detection of her last cellular activity was a cell radio network "ping" ...
[[ in this context a ping is basically a method of establishing communication and measuring signal strength *FROM* a transceiver (tower) via its antenna *TO* a handheld transceiver (Your phone!), which also is also has an antenna, using the protocols of CDMA or GSM... ]] i tried to keep that brief
Why am I rambling about this??
(Quoted from above linked article)
"GPS tracking aids investigators in Drexel case"
"Ryan Graham with HTC says GPS tracking technology has evolved over the last 10 years and continues to get better."
Here it comes folks...
IT HAS ABSOLUTELY NOTHING TO DO WITH ANYTHING IN THIS CASE!
A cell phone ping is not GPS logged coordinates... If it were a GPS signal that was tracked and logged, it would have indicated her location within a few feet! A GPS uses a satellite to gather location info, not towers.
Ok, enough of that... This is a story that should have never made it by the editor...
(disclaimer - this is me voicing my (strong and somewhat coarse) opinion)
a little bit of nerdy slightly-OT stuff for anyone interested:
(conspiracy theorists are going to love this) The govt doesn't track and log our every move with our cell phones, nor does our cell phone companies. What is logged is the association via the cellular network with nearby transceivers/towers. It is logged with a relative consistency and is still used to an extent for billing purposes - hence the term "roaming".
UNDER PROPER AUHORITY cell phone companies can activate GPS in some phones to provide location
IIRC Brittanee's last cell signal hit only 1 tower located just north of G-C line near hwy 17... It was all that was within range... unfortunately this leaves the entire maximum radius of the tower. sucks!
From what I have gathered, tower similar to one that may be used in an area such as this, has a radius of up to 11 miles.
For those who watch CSI and heard the term (passive or active) Triangulation? Triangulation is when you communicate (ping) with 3 (or more) transceiver/towers, you are then narrowed down to a smaller area - the area in which these transceiver/tower's signal strength overlaps. the more transceivers your phone "talks to" (or pings) the more precise can your phone be located)
This is how "google maps" works on a cell phone that is NOT GPS equipped, but of course it is going to be MUCH more erroneous than GPS location.