The central area of LOFAR - The LOFAR core
The heart of LOFAR will beat on an area of about 320 ha (3x2km) close to the village Exloo in the Province Drenthe situated in the Northern part of the Netherlands. This area is currently transformed into a natural reserve. The radio antennas are placed on mounds that are prepared among the reserve. This will provide a realtively quiet area and disturbing signals that are produced by mankind are reduced to a minimum. There will be 18 of such mounds equipped with radio antennas.
This reshaping of the landscape takes place in collaboration with and under the lead of the Drentse Landschap.
In addition, also the geophysical sensors (geophones and infrasound) will get their place in Exloo. These sensors will be placed there and form two arrays. Another bigger array of geophones will be placed close to Annerveen.
In the figure to the right the planned LOFAR radio antenna stations in the core can be seen. The big circle indicates the LBA fields and the small circles the HBA fields. The 18 stations that are currently constructed are coloured in red. Blue and yellow colour means that these stations will be prepared and are ready for hardware to be placed on. White coloured stations will not be prepared but it is not excluded that hardware will be placed there at a later stage.
Remote LOFAR Stations
The amount of details that can be seen on an radio astronomical image is dependent on the distance/baselines on which the radio antennas are placed. Therefore, 18 further stations are placed in the close vicinity of the core and out to distances of 100 km within the Netherlands. The challenge for these remote stations is to find an isolated place that is at a distance to any civilisation and is suited for a LOFAR station.
At most of these locations, the geophysical sensors (geophones and infrasound) are placed as well as radio antennas to make optimal use of the developed fibre infrastructure.
International LOFAR Stations
The capabilities of LOFAR can be increased dramatically by broadening the scope to a European level, thus creating a European Sensor Network.
Although the LOFAR project was funded initially within the Netherlands, the European astronomical community got very enthusiastic and raised funding in their own countries for 8 further LOFAR stations to be placed in their countries at a distance to the core of at most 1000 km. These countries are Germany (5), UK (1), France (1) and Sweden (1). More detail can be found here.
Astronomers of other European countries - in particular Italy, Poland, Austria and the Ukraine, are keen to contribute with other means, eg. manpower for software development, etc. In addition, they try to raise funding to host a LOFAR station in their country.
Although there have been inititiatives to broaden the European involvement to the other applications, this has not been successful yet.