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Doppler spectroscopy (also known as the radial-velocity method, or colloquially, the wobble method) is an indirect method for finding extrasolar planets and brown dwarfs from radial-velocity measurements via observation of Doppler shifts in the spectrum of the planet's parent star. As of November 2022, about 19.5% of known extrasolar planets ...
Minimum mass is a widely cited statistic for extrasolar planets detected by the radial velocity method or Doppler spectroscopy, and is determined using the binary mass function. This method reveals planets by measuring changes in the movement of stars in the line-of-sight , so the real orbital inclinations and true masses of the planets are ...
A separate novel method to detect exoplanets from light variations uses relativistic beaming of the observed flux from the star due to its motion. It is also known as Doppler beaming or Doppler boosting. The method was first proposed by Abraham Loeb and Scott Gaudi in 2003. [35]
Doppler imaging was first used to map chemical peculiarities on the surface of Ap stars.For mapping starspots it was first used by Steven Vogt and Donald Penrod in 1983, when they demonstrated that signatures of starspots were observable in the line profiles of the active binary star HR 1099 (V711 Tau); from this they could derive an image of the stellar surface.
The method was first described by Philip Njemanze in 2007, and was referred to as functional transcranial Doppler spectroscopy (fTCDS). [ 25 ] fTCDS examines spectral density estimates of periodic processes induced during mental tasks, and hence offers a much more comprehensive picture of changes related to effects of a given mental stimulus.
Absence of the portal system in a first trimester case associated with hygroma and aorto-umbilical fistula. (A): Transverse plane of the upper abdomen with color Doppler applied, showing umbilical cord insertion, stomach, the prominent hepatic artery and no afferent liver venous perfusion; (B): midsagittal plane reconstructed from a three-dimensional volume acquisition were the crown-rump ...
Ultrasound Doppler imaging can be used to obtain basic functional measurements of brain activity using blood flow. In functional transcranial Doppler sonography, a low frequency (1-3 MHz) transducer is used through the temporal bone window with a conventional pulse Doppler mode to estimate blood flow at a single focal location.
Doppler Optical Coherence Tomography is an extension of OCT, where it combines the Doppler effect principle to achieve high resolution tomographic images in biological tissues. And because of its high resolution and velocity sensitivity, there are many applications in the medical field. The basic phenomenon of Doppler OCT can be explained below.