Doppler

American  

[dop-ler] / ˈdɒp lər /

noun

1. Christian Johann, 1803–53, Austrian physicist: discovered the Doppler effect.

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Doppler Scientific  

/ dŏp′lər /

1. Austrian physicist and astronomer who in 1842 explained the effect, now named for him, of variations in the frequency of waves as a result of the relative motion of the wave source with respect to the observer.

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Example Sentences

Doctors and nurses with Doppler machines and ultrasounds kept showing up, forcing them to hear the heartbeat and see the movement of a tiny body.

From Salon • May 27, 2026

A system called Trackman uses in-stadium, two-directional Doppler radar and synchronized high-speed cameras to quantify everything from a ball’s rotation and velocity to location.

From The Wall Street Journal • Apr. 30, 2026

These motions appear as slight Doppler shifts in the star's light.

From Science Daily • Nov. 13, 2025

Bilateral lower extremity venous Doppler ultrasounds were performed and revealed chronic venous insufficiency, a benign and common condition, particularly in individuals over the age of 70.

From Slate • Jul. 18, 2025

Indeed, the police make use of the Doppler effect to measure the speed of cars by measuring the wavelength of pulses of radio waves reflected off them.

From "A Brief History of Time: And Other Essays" by Stephen Hawking