GPS does not require satellites. I'm not sure why you persist in spreading this myth.
There is no way to emulate the signals sent by gps satellites. The frequencies 1.023 MHz and 10.23 MHz are strictly line of sight.
As I said, your failure to understand how complex the system actually is, is not material to its being effective.
I log the information sent by satellites from multiple locations simultaneously. The satellites enter and exit the field of view exactly as predicted by their flightpaths and speeds.
Setting up receivers at 2 locations, which have a large mountain between them, will have the correct signal masking as satellites travel behind the mountain (even a parked truck can block signal, something I have personally observed.
The x,y location of the satellites, as well as its altitude, are all used in the calculations to determine location.