Direct Detection of Radio Waves Low Frequency Array LOFAR

The LOFAR project (LOw Frequency ARray) is a Dutch project undertaken by the ASTRON Institute, which brings together in the same consortium 18 European research organisations, the majority Dutch and Germany. The aim of this project is not just astrophysical, because institutes carrying out research into geophysics and agronomy are equally involved. The array actually consists of radio aerials, but also includes 3-axis geophones and microbarometers. From the astrophysical point of view, the aim is to construct a giant aperture-synthesis radiotelescope, the size and equivalent area of which are 100 times that of the largest array currently in existence in this frequency region (Kharkov in the Ukraine).

The principle on which the array is based consists of a core, and more distant stations, thus creating several baselines (Fig. 8.31). The first version consists of 32 stations installed at Drenth (in the Netherlands), and 45 peripheral stations providing maximum baselines of about 100 km. Table 8.8 describes the parameters of this so-called 'nominal' configuration, and Table 8.9 gives the performance as a function of frequency. It should be noted that in terms of equivalent surface, LOFAR has four times the extent of the UTR array at Kharkov.

Table 8.8 Characteristics of the nominal configuration of the LOFAR array (Source: project site)

Frequency band

Low frequencies

30-80 MHza

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