the change in frequency or wavelength of a wave in relation to an observer who is moving relative to the source of the wave, producing a shift in pitch or color
أمثلة
The Doppler effect is employed in police radar guns to measure the speed of moving vehicles.
يتم استخدام تأثير دوبلر في بنادق الرادار الشرطية لقياس سرعة المركبات المتحركة.