Doppler effect is the change of frequency of wave of an observer when moving in accordance with the wave source. You can calculate the doppler shift for the New frequency (f'), Source frequency (f0), Receiver velocity (ur) and Wave velocity (v) of an approaching Receiver with the below Doppler Effect Approaching Receiver Formula. It is also known as doppler shift formula, helps to find the wave velocity based on the receiver velocity, new and source frequency.
Doppler Effect approaching receiver can be defined as the effect produced by a moving source of waves with a downward shift in frequency for observers from whom the source is receding.