By Cody, Darren, and Katie

GPS

• 24 satellites with a minimum of 21 operating 98% of the time

• 6 Orbital planes • visible for

approximately 5 hours above the horizon

• As few as 4 and as many as 12 in “view” at any time, any place

Mathematics in GPS

•x, y, z are the positions we are trying to locate •T = the time error at the receiver •xs, ys, zs are the satellite positions (calculated •Es = a sum of all the modeling errors considered by the GPS •(include tropospheric and ionospheric errors, clock errors from the satellite and any other error the GPS receivers thinks is significant enough to model) •Prs is the approximate (pseudo-range) distance from the receiver to the satellite

2 2 2

s s sPrs T Es x x y y z z

http://education.uncc.edu/droyster/talks/NCTM_2003/NCTM%202003_files/frame.htm

http://imageatlas.globexplorer.com/ImageAtlas/view.do

•A vehicle tracking system is an electronic device installed in a vehicle to enable the owner or a third party to track the vehicle's location