So I'm planning to start a project using the Doppler shift to calculate the velocity of a moving object. The problem is, I'm not sure which equations I should use, and I saw many different equations around the Internet. So are these equations correct? If not, can someone tell me what the correct ones are? Equations: Source moving towards you: f’ observed frequency f’ = f / [1 – (v/vs)] Source moving away from you: f’ observed frequency f’ = f / [1 + (v/vs)] Thank you very much!