Whatever you do, PLEASE PLEASE PLEASE DO NOT TRANSMIT BETWEEN 1.100 Ghz and 1.600 Ghz. GPS receivers operate on very low power signals and it's entirely possible to accidentally jam them even without high power signals. If you are near the approach path for an airport you can cause serious problems.

https://github.com/Mictronics/pluto-gps-sim

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

Or if you use them, do so in a completely RF shielded environment. You wouldn't want to wreck havok with drones, Lime scooters, Bird Scooters, cell phones, etc. Right? :)