Defining the period measured by a moving observer relative to a stationary source as(adsbygoogle = window.adsbygoogle || []).push({});

T=t(n)-t(n-1) where t(n) and t(n-1) represent the times when two successive wavecrests are received respectively, the theory of the Doppler Effect leads zero and negative periods in the case of sonic and supersonic motions of the observer. . Do you consider that a zero period is associated with the fact that the moving observer receives one and the same wave crest, a negative period being associated with a reversal in the order in which the wave crests are received.

Thanks for your answers

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# Acoustic doppler effect at subsonic, sonic and supersonic speeds

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