LOFAR

LOFAR, or the Low Frequency Array, is a large radio telescope network designed for low-frequency radio astronomy. Its components are spread primarily across the Netherlands with additional stations in several European countries. LOFAR is based on aperture array technology, using many simple dipole antennas grouped into stations. Signals from individual antennas are digitized and processed with software to form multiple beams, enabling wide-field, high-sensitivity observations without movable dish structures.

The project was constructed and is operated by ASTRON, the Netherlands Institute for Radio Astronomy, in collaboration with international partners. Since its commissioning, LOFAR has demonstrated advanced digital signal processing and data handling for low-frequency interferometry. The array operates in the roughly 10 to 240 MHz range, with a dense core for high sensitivity and longer baselines to remote stations that provide higher angular resolution.

LOFAR supports a broad range of science goals. It is used to study the early universe, including cosmic dawn and reionization, as well as the formation and evolution of galaxies and galaxy clusters. It also contributes to research on cosmic magnetism, pulsars, fast radio transients, and solar-system radio emission. The observatory is particularly active in time-domain and survey science, including large-scale sky surveys that map radio galaxies, clusters, and star-forming regions.

Key observing programs include LOFAR surveys that produce extensive sky maps and enable multi-wavelength studies. Data are processed with specialized pipelines and are made available to the international scientific community. LOFAR remains a major example of European collaboration in radio astronomy and continues to influence technology development and scientific discovery in the low-frequency regime.