Radio astronomy can be recorded and pieced together in a mosaic image. The type of instrument used depends on the strength of the signal and the amount of detail needed. Observations from the Earth's surface are limited to wavelengths that can pass through the atmosphere. At low frequencies, or long wavelengths, transmission is limited by the ionosphere, which reflects waves with frequencies less than its characteristic plasma frequency. Water vapor interferes with radio astronomy at higher frequencies, which has led to building radio observatories that conduct observations at millimeter wavelengths at very high and dry sites, in order to minimize the water
Waves Radio annual Scottish Week celebrations. Following the success of the initial broadcasts the station returned every summer, with the introduction of additional broadcasts made over the Christmas periods in 1994 and 1995. The station ceased broadcasting in July 1996 and was unable to transmit over the festive period due to the announcement of the full-time licence. After gaining a full-time licence, Waves Radio launched on 6 December 1997, from its current studios at Blackhouse Circle. Glenn Moir is the stations news editor, responsible for producing the daily local news bulletins. These are broadcast at 8.30am, 12.30pm and 5.30pm Monday - Friday.