About LOFAR

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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 IV

Images taken by: Jan-Pieter de Reijer

Placing the High Band Antennas

Compared to the relatively easy assembly of the Low Band Antennas, the placement of the High Band Antenna (HBA) tiles (which operate between 115 and 250 MHz) is a considerably more complicated procedure. The antennas are pre-assembled at a production facility in Exloo and transported one by one to the field on a trailer. A crane then hoists the tiles, which weigh 150 kg each and measure 5m x 5m, into place. The tiles are fixed to the ground with deep anchors, to ensure that they can resist high winds. Each of the "black boxes" actually contains 16 antenna elements, laid out in a 4x4 grid, whose signals are combined in a time-delay beamformer inside the tile. The HBA's are covered by a uv-resistant flexible polypropylene foil that protects the interior of the tile from the elements.

The stations in the Netherlands will each have 48 HBA tiles. On the LOFAR stations in- or close to the core the HBA's are equally divided over two fields. In observations, these two fields act as individual stations, which therefore contribute to a significantly better uv-coverage and improve the imaging quality of the inner part of LOFAR. Outside the core area, all 48 HBA's are placed in a single field. The international LOFAR stations each have 96 HBA's.

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