Cosmic microwave telescope. Daytime view of the dish antenna of a radio telescope at Owens Valley in California, USA. This cosmic microwave telescope has a dish with a diameter of 40 metres (130 feet). Microwaves are radio waves with wavelengths between about 1 millimetre and 1 metre. The cosmic microwave telescope is one of a number of types of radio telescope at Owens Valley station. Owens Valley also has a 25 metre diameter radio telescope which forms part of the Very Long Baseline Array (VLBA) network. This network consists of ten VLBA stations ranging from the Virgin Islands to Hawaii which together act like a giant telescope.