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Large radio telescope have pretty good pointing accuracy: the individual dishes of the VLA are accurate to about 10 arcsec. the giant Lovell telescope at Jodrell Bank has a similar accuracy. The second critical parameter is the beam width. Beam width depends highly on frequency: beamwidth = wave length/dish diameter When you use several dishes in an ...


They scan the object, if you point the dish a a point in the sky as the Earth rotates the dish scans across astronomical objects, then move the dish to point at a slightly different position and let it scan across the object again, and again. After a while you can re-construct an image from the scan lines in a similar way to analogue TV.


A uniform disk has been subtracted to better show the fine banded structure on the planet. This means the surface of the planet is far brighter (in the raw data) than the surrounding magnetosphere. The planet itself has been darkened considerably in the image, otherwise it would be a pale circle and show little or no detail. The press release from the VLA'...

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