olemus
kiirguse sageduse muutumine,
mida tajub vaatleja või vastuvõtja
kiirgusallika liikumisel vaatleja suhtes
(esmakirjeldus: Chr. Doppler, 1842)

Oxford Languages:
physics
an increase (or decrease) in the frequency of sound, light, or other waves as the source and observer move towards (or away from) each other. The effect causes the sudden change in pitch noticeable in a passing siren, as well as the red shift seen by astronomers

näide
https://www.youtube.com/watch?v=imoxDcn2Sgo

ülevaateid
https://www.youtube.com/watch?v=h4OnBYrbCjY

https://en.wikipedia.org/wiki/Doppler_effect

rakendusi
http://www.actforlibraries.org/practical-uses-of-the-doppler-effect/

https://lidarandradar.com/20-applications-of-doppler-effect/

https://opensky-network.org/files/publications/schaefer16a.pdf