Taming the beast: operating the world's largest low-frequency radio observatory LOFAR

Abstract

The construction of the Low-Frequency Array (LOFAR) radio telescope is nearly finished. LOFAR is currently being prepared to run a large variety of science projects for the years to come. LOFAR is a geographically widely distributed radio telescope consisting of, currently, 41 separate stations, or antenna fields. The majority of stations is situated in the northern part of the Netherlands. These Dutch stations are complemented by 8 stations in Germany, France, UK and Sweden. LOFAR uses a novel design with phased array technology for the antenna fields. It is built to receive sky signals with frequencies between 10 and 250 MHz, for which is uses two different types of antenna. LOFAR stations produce up to 4 Gb/s of digital data each, which are sent to a central processing facility hosted by the University of Groningen computing center, CIT. There the data streams are combined and processed to produce astronomically meaningful data. The processed data is archived in several large datacenters and made available to end-users. LOFAR produces science for radio pulsar studies, cosmic ray studies, sensitive wide-field imaging and many other applications. Much of the flexibility of LOFAR has been made possible by the abundant use of software and general purpose programmable hardware in its design. The versatility and geographical spread of the telescope stations and its resources leads to fascinating challenges in operations and maintenance. In this presentation I will present the operational concepts and challenges of the LOFAR telescope, and the solutions the LOFAR team has created for these.