LOFAR is the first radiotelescope of a new generation, which can be described as “software telescopes”. Observing between 15 and 240 MHz, the main complexity of LOFAR does not lie in the receivers (crossed, active dipoles), but in the hierarchical organisation of a large number of antennae (almost 50 000) and in the analysis of the incoming data in a large computing facility. Rather than mechanically steering the telescope, pointing occurs fully numerically, and all observations are pre-processed on the fly to obtain a reasonable data volume. LOFAR will be 10 to 100 times more sensitive than the current instruments in the same frequency range. It will achieve sub-arcsecond resolution, which is 10 to 100 times better than the resolution of existing low-frequency instruments. It is also one of the most flexible instruments, making it interesting for a large number of scientific fields.
LOFAR est le premier radiotélescope dʼune nouvelle génération dʼinstruments dit « télescopes numériques ». Observant entre 15 et 240 MHz, la complexité de LOFAR ne repose pas dans les capteurs (dipôles croisés), mais dans lʼorganisation hiérarchique dʼun grand nombre dʼantennes (près de 50 000) et du traitement des données dans un grand centre de calcul. Le pointage est entièrement numérique, et toutes les observations sont pré-traitées en direct pour parvenir à un débit gérable. LOFAR aura une sensibilité 10 à 100 fois supérieure à celle des instruments existants dans cette gamme de fréquences. Sa résolution angulaire sera proche dʼune seconde dʼarc, 10 à 100 fois plus élevée que la résolution disponible jusquʼà maintenant. LOFAR est également lʼun des instruments les plus flexibles, ce qui le rend intéressant pour un grand nombre de domaines scientifiques.
Mot clés : LOFAR, Radiotélescope, Radioastronomie
Jean-Mathias Grießmeier 1; Philippe Zarka 2; Michel Tagger 1; on behalf of the LOFAR Collaboration 
@article{CRPHYS_2012__13_1_23_0, author = {Jean-Mathias Grie{\ss}meier and Philippe Zarka and Michel Tagger and on behalf of the LOFAR Collaboration}, title = {Radioastronomy with {LOFAR}}, journal = {Comptes Rendus. Physique}, pages = {23--27}, publisher = {Elsevier}, volume = {13}, number = {1}, year = {2012}, doi = {10.1016/j.crhy.2011.11.002}, language = {en}, }
TY - JOUR AU - Jean-Mathias Grießmeier AU - Philippe Zarka AU - Michel Tagger AU - on behalf of the LOFAR Collaboration TI - Radioastronomy with LOFAR JO - Comptes Rendus. Physique PY - 2012 SP - 23 EP - 27 VL - 13 IS - 1 PB - Elsevier DO - 10.1016/j.crhy.2011.11.002 LA - en ID - CRPHYS_2012__13_1_23_0 ER -
Jean-Mathias Grießmeier; Philippe Zarka; Michel Tagger; on behalf of the LOFAR Collaboration. Radioastronomy with LOFAR. Comptes Rendus. Physique, Volume 13 (2012) no. 1, pp. 23-27. doi : 10.1016/j.crhy.2011.11.002. https://comptes-rendus.academie-sciences.fr/physique/articles/10.1016/j.crhy.2011.11.002/
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