Here is a graphic to add to that explanation if anyone is curious: http://gis.stackexchange.com/questions/12866/why-does-gps-positioning-require-four-satellites

Here is a graphic to add to that explanation if anyone is curious: http://gis.stackexchange.com/questions/12866/why-does-gps-positioning-require-four-satellites http://gis.stackexchange.com/questions/12866/why-does-gps-po...