Does anyone have a technical explanation of how gps spoofing works?

Here is some slides from Defcon 23 : https://media.defcon.org/DEF%20CON%2023/DEF%20CON%2023%20pre...

They did a record, replay with a USRP B210 and GPS antenna.

And here is a project that generates GPS baseband signal data streams for bladeRF, HackRF, and USRP.

https://github.com/osqzss/gps-sdr-sim