A tool used for computing frequency changes caused by the relative motion between a source and an observer, typically of sound or electromagnetic waves, determines the altered frequency perceived by the observer. For example, the change in pitch of a siren as an ambulance approaches and then recedes demonstrates this phenomenon in the audible spectrum. The tool allows for precise calculation of this change based on the velocities of the source and observer and the original frequency.
Understanding this frequency shift is crucial in diverse fields. In astronomy, it helps determine the radial velocity of celestial objects, contributing to our understanding of the universe’s expansion. In meteorology, weather radar utilizes this principle to track storms and predict their movement. Medical ultrasound imaging also relies on this effect to visualize blood flow and internal organs. Historically, the Austrian physicist Christian Doppler first described this phenomenon in 1842, and it has since become a foundational concept in physics and various applied sciences.
