Introduction to Radio Astronomy and Interferometry

Paragraph 1

For more information on each of the sentences below, click on the text of the sentence. For more information on all the sentences click here.

Radio astronomy uses radio waves to study regions of space.

Radio waves are a form of electromagnetic radiation - like visible light waves only with much longer wavelengths. Visible light waves are oscillating electromagnetic signals with wavelengths of less than one millionth of a metre, whereas radio waves have wavelengths in the range of a few millimetres to several metres. Radio telescopes gather and concentrate the radio waves from an astronomical source. The signal received is then electronically processed so that it can be measured by a computer. When a picture of an area of the sky is to be built up the signals are stored in a computer and displayed as a radio-wave intensity map of the region being observed. The Australia Telescope National Facility is a world leader in the technology associated with radio astronomy and in the astrophysics of sources that emit radio waves.

Single-dish radio telescopes produce blurry images.

Interferometry is a technique used to overcome the blurring and produce sharper radio images.

The spacing between the radio telescope dishes in an interferometer determines the size of the objects that can be resolved by the interferometer.

Using many dishes together in an interferometer array allows astronomers to form more complete images of objects.

This is how an aperture synthesis telescope such as the Australia Telescope Compact Array works.

VLBI (Very Long Baseline Interferometry) enables very small objects to be clearly resolved.


Go to Introduction to Radio Astronomy and Interferometry Summary

Last update by Michelle Storey. 14/2/99


About Us | Observers | Education | Research
Search | Latest News | Contents | Home

CSIRO - Australian Science, Australia's Future

- (wwwcomment @ atnf.csiro.au)

Projects
Public