The license plate will change sometimes for security. (Decoy vehicles and such). To my knowledge, there is no ground call sign like you're thinking because the USSS is in control on the ground. USSS uses a code name (Mogul for your favorite president)
Air Force One only means an air force controlled flight the president is on. Army One would be of the president was on an Army aircraft and so on. Executive One is civilian.
The license plate will change sometimes for security. (Decoy vehicles and such). To my knowledge, there is no ground call sign like you're thinking because the USSS is in control on the ground. USSS uses a code name (Mogul for your favorite president)
Air Force One only means an air force controlled flight the president is on. Army One would be of the president was on an Army aircraft and so on. Executive One is civilian.
I noticed this too!