Something is not right with my result :(

Sorry for the noob question. So if I want to get 4 years worth of displacement change, I basically need to compare 12 day interval for the entire 4 years. Which is about 365*4 / 12 = 122 computations. And therefore, I should use the automated batch processing instead of running the process 122 times manaully.

Is there any good/complete tutorial on this?