About LOFAR

Address

Oude Hoogeveensedijk 4
7991 PD Dwingeloo
The Netherlands
(+31) (0)521 595 100

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Astron

Initiator: ASTRON Netherlands Institute for Radio Astronomy

eu  SNN

This project was co-financed by the EU, the European Fund for Regional Development and the Northern Netherlands Provinces (SNN), and EZ/KOMPAS.

Building LOFAR: CS302 - the first LOFAR station III

Images taken by: Jan-Pieter de Reijer and Henri Meulman   

Placing the Low Band Antennas

Each LOFAR station has 96 Low Band Antennas (LBAs). In the Netherlands these are connected to 48 receivers, which means that half the 96 antennas can be used at any time. In this way, different configurations can be used at low and high frequencies in the LBA band which runs from 10 to 80 MHz. The antennas are distributed in a roughly circular area, 70 m in diameter. The signals are detected using the wires that emanate from the black block at the top of PVC pole which contains the Low Noise Amplifier, which amplifies the signals so that they can be transported to the cabinet, where they are digitised in the receiver. The antenna wires are connected to a piece of cord on one side and a rubber spring on the other side. These are fastened to the ground using anchors. Because each antenna receives two orthogonal polarisations, the whole structure is stable. The antenna ground plane is a steel mesh that is normally used to reinforce concrete. Beneath the mesh is a mat which is there to prevent vegetation from covering the antenna. Note that the antennas are not fastened to the ground plane. Erecting a field of LOFAR LBA's only takes a couple of days, once the preparations (flattening of the field and laying of the cables) have been completed.

ASTRON initiated LOFAR as a new and innovative effort to force a breakthrough in sensitivity for astronomical observations at radio-frequencies below 250 MHz. 
Development: Dripl | Design: Kuenst   © copyright 2020 Lofar