DISCLAIMER: This article is being kept online for historical purposes. Though accurate at last review, it is no longer being updated. The page may contain broken links or outdated information.
Long-baseline optical interferometry
Elias, Nicholas Astrometry Department, Navy Prototype Optical Interferometer, U.S. Naval Observatory, Washington, DC.
- Large telescopes
- Reduction of turbulence effects
- Long-baseline interferometry
- Aperture synthesis
- Related Primary Literature
The phrase “to spatially resolve” refers to the ability to see structure in objects or to separate individual objects in an image. The maximum spatial resolution is given by Eq. (1), where θ is the minimum measurable separation in arc-seconds (an arc-second is 1/60 of an arc-minute or 1/3600 of a degree), λ is the wavelength of the light in nanometers (1 nm = 10−9 meter), and D is the size of the aperture through which the light travels in meters (1 m ≈ 3.3 ft). This resolution limit may be explained by the diffraction of light through the aperture, a process which smears images. (The maximum spatial resolution is also called the diffraction limit.) An alternative explanation is that some spatial information from the source is lost because only a fraction of its light gets through the aperture. The human eye is most sensitive to light at λ ≈ 500 nm (yellow light), and its pupil is typically D ≈ 2 mm in diameter, which translates to a spatial resolution of approximately 60 arc-seconds (1 arc-minute). Unfortunately, this resolution is not enough to produce images of stellar surfaces or to chart the orbits of binary star systems. To overcome the limitations of the human eye, astronomers since Galileo have constructed telescopes and instruments to increase resolving power (or, to increase the effective size of the eye's pupil).
The content above is only an excerpt.
for your institution. Subscribe
To learn more about subscribing to AccessScience, or to request a no-risk trial of this award-winning scientific reference for your institution, fill in your information and a member of our Sales Team will contact you as soon as possible.
to your librarian. Recommend
Let your librarian know about the award-winning gateway to the most trustworthy and accurate scientific information.
AccessScience provides the most accurate and trustworthy scientific information available.
Recognized as an award-winning gateway to scientific knowledge, AccessScience is an amazing online resource that contains high-quality reference material written specifically for students. Contributors include more than 10,000 highly qualified scientists and 45 Nobel Prize winners.
MORE THAN 8700 articles covering all major scientific disciplines and encompassing the McGraw-Hill Encyclopedia of Science & Technology and McGraw-Hill Yearbook of Science & Technology
115,000-PLUS definitions from the McGraw-Hill Dictionary of Scientific and Technical Terms
3000 biographies of notable scientific figures
MORE THAN 19,000 downloadable images and animations illustrating key topics
ENGAGING VIDEOS highlighting the life and work of award-winning scientists
SUGGESTIONS FOR FURTHER STUDY and additional readings to guide students to deeper understanding and research
LINKS TO CITABLE LITERATURE help students expand their knowledge using primary sources of information