Aperture Synthesis
Aperture synthesis is a method of radio astronomy used to obtain high-resolution images from radio telescopes. It is based on the principle that any two or more antennae, separated by some distance and operating in unison, can effectively act as one larger antenna with twice the resolution of a single element. This technique has been widely adopted since its invention in the 1950s and has revolutionized modern astrophysics and cosmology.
The basic idea behind aperture synthesis was developed by Sir Bernard Lovell at Jodrell Bank Observatory in England during World War II when radar technology was being employed to detect aircraft at long ranges using multiple antennas spaced apart (known as ‘arrays’). This same concept can be applied to astronomical observations of distant objects such as quasars, pulsars and galaxies; even though these objects are not detectable directly, their signals can be combined together to create an image which reveals their structure.
In practice, it involves combining data from several antennas into one data set by means of interferometry. Each individual antenna will measure the incoming radiation over a range of frequencies; this information is then combined mathematically so that only signals originating from the same source are added together while noise from other sources is filtered out or minimized. The result is an image with much higher resolution than could have been obtained using just one element alone due to increased signal-to-noise ratio (SNR).
Today’s most powerful arrays consist of many dozens or even hundreds of elements spread across large distances – often kilometers – making them capable of producing extremely detailed images with resolutions approaching those attainable through optical methods (such as Hubble Space Telescope). With such instruments scientists have made significant progress in understanding our universe: for example they have mapped out interstellar gas clouds where stars form, charted magnetic fields around neutron stars and observed supermassive black holes at our galaxy’s center!
The applications for aperture synthesis go far beyond astronomy however; similar techniques are also used for medical imaging (PET/CT scans), geophysical surveys (seismology) and communications systems engineering among others. In addition new research continues to push forward both technical capability and scientific knowledge about our universe – opening up exciting possibilities for further discoveries yet unseen!