A dopplergraph or dopplergram is a two-dimensional representation of the approaching and receding motions of an object or area.
The word "dopplergraph" is a combination of the words
doppler and
photograph
A photograph (also known as a photo, image, or picture) is an image created by light falling on a photosensitive surface, usually photographic film or an electronic image sensor, such as a CCD or a CMOS chip. Most photographs are now creat ...
. Dopplergraphs are two-dimensional records of variations in the
doppler shift
The Doppler effect or Doppler shift (or simply Doppler, when in context) is the change in frequency of a wave in relation to an observer who is moving relative to the wave source. It is named after the Austrian physicist Christian Doppler, who ...
in light intensity.
Dopplergraphs do not need to be a record of the shift of visible light, but of any radiated wave, which includes
electromagnetic waves
In physics, electromagnetic radiation (EMR) consists of waves of the electromagnetic (EM) field, which propagate through space and carry momentum and electromagnetic radiant energy. It includes radio waves, microwaves, infrared, (visible) lig ...
and acoustic waves.
Because the doppler shift is caused by the velocity of the radiating source towards or away from the viewer, a dopplergraph is a picture of the velocities associated with the sources being viewed.
See also
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Spectrogram
A spectrogram is a visual representation of the spectrum of frequencies of a signal as it varies with time.
When applied to an audio signal, spectrograms are sometimes called sonographs, voiceprints, or voicegrams. When the data are represen ...
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Spectroheliograph
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Spectrohelioscope
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Solar Dynamics Observatory
The Solar Dynamics Observatory (SDO) is a NASA mission which has been observing the Sun since 2010. Launched on 11 February 2010, the observatory is part of the Living With a Star (LWS) program.
The goal of the LWS program is to develop th ...
References
Doppler effects
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