speckle interferometry

A technique whereby the limit to the resolution of a telescope, imposed not by its design but by atmospheric turbulence (see seeing), may be considerably improved: factors of 50 have been reported. A typical stellar image has, at best, a diameter given by that of the diffraction-limited Airy disk; atmospheric turbulence however causes small continuous erratic movements in image position on a long-exposure photograph, producing a final blurred image enlarged many times. In optical speckle interferometry and its more recent infrared counterpart, many short exposures (10–20 milliseconds) of the object are taken in rapid succession. These freeze the effects of turbulence so that the individual ‘speckles' making up the overall image are distortion-free stellar images: those of supergiants are relatively large, those of binary stars are double. Substantial differences between the speckles of the many short exposures require the application of statistical analysis to the images. This leads to a range of information, including the separation and other properties of close binary stars, often hitherto unresolvable. In addition reconstructions have been achieved of the disks of supergiants, such as Betelgeuse; apparent diameters can thus be measured and large-scale surface details discerned. Very small areas of the Sun have also been studied.

speckle interferometry

[′spek·əl ‚in·tər·fə′räm·ə·trē] (optics) The use of speckle patterns in the study of object displacements, vibration, and distortion, and in obtaining diffraction-limited images of stellar objects.

单词	speckle interferometry
释义	speckle interferometry speckle interferometry n (Astronomy) astronomy a technique to increase the angular resolution of telescopes that are impaired by atmospheric turbulence, in which the information from a number of exposures of very short duration is combined Translations interferometria a chiazzeinterferometria spettro speckle interferometry speckle interferometry A technique whereby the limit to the resolution of a telescope, imposed not by its design but by atmospheric turbulence (see seeing), may be considerably improved: factors of 50 have been reported. A typical stellar image has, at best, a diameter given by that of the diffraction-limited Airy disk; atmospheric turbulence however causes small continuous erratic movements in image position on a long-exposure photograph, producing a final blurred image enlarged many times. In optical speckle interferometry and its more recent infrared counterpart, many short exposures (10–20 milliseconds) of the object are taken in rapid succession. These freeze the effects of turbulence so that the individual ‘speckles' making up the overall image are distortion-free stellar images: those of supergiants are relatively large, those of binary stars are double. Substantial differences between the speckles of the many short exposures require the application of statistical analysis to the images. This leads to a range of information, including the separation and other properties of close binary stars, often hitherto unresolvable. In addition reconstructions have been achieved of the disks of supergiants, such as Betelgeuse; apparent diameters can thus be measured and large-scale surface details discerned. Very small areas of the Sun have also been studied. speckle interferometry [′spek·əl ‚in·tər·fə′räm·ə·trē] (optics) The use of speckle patterns in the study of object displacements, vibration, and distortion, and in obtaining diffraction-limited images of stellar objects.
随便看	board certification in special education board certified board-certified board certified - advanced clinical diabetes management board certified ambulatory care pharmacist board certified anesthesiologist board certified art therapist board certified associate behavior analyst board certified atlas orthogonist board certified avian vet board certified behavior analyst board certified biblical counselor board certified/board eligible board certified chaplain board certified christian counselor board certified clinical psychotherapist board certified clinical thermographer board certified companion animal behaviorist board certified compulsive gambling counselor board certified continuing education board certified criminal defense investigator board certified diplomate board certified educational therapist board certified entomologist board certified environmental engineer