An aperture synthesis radio telescope consisting of numerous phased arrays observing at 10–240 MHz (wavelengths of 30–1.25 m) built by a consortium of European countries led by the Netherlands. LOFAR consists of 51 stations each containing up to 192 antennas. The central core of the LOFAR array, 3 × 2 km across and containing 24 stations, is at Exloo in the northern Netherlands. An additional 14 stations are sited in the Netherlands at distances up to 50 km from the core. Six other countries have built 13 more stations: Germany (6 stations), Poland (3), the UK (1), France (1), Sweden (1), and Ireland (1), giving baselines up to 1900 km. The simple omnidirectional antennas are of two types: low-band antennas (LBA) sensitive to the range 10–80 MHz and high-band antennas (HBA) sensitive to 110–240 MHz. The Dutch stations consist of 48 HBAs and 96 LBAs, while the international stations have 96 of each. Signals from the stations are combined in a central processor at Groningen, Netherlands. LOFAR was opened in 2012, although it was not then fully complete. Seismic geophones, bio-sensors, and weather instruments installed at various stations will make LOFAR not only a radio telescope but also a sensor platform for geophysicists and agricultural scientists.

http://www.lofar.org/ Official telescope website.