EPJ Web of Conferences 216, 04006 (2019)
https://doi.org/10.1051/epjconf/201921604006

Updated Calibration of the LOFAR Low-Band Antennas

¹ Astrophysical Institute, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels Belgium
² Department of Astrophysics/IMAPP, Radboud University, P.O, Box 9010, 6500, GL Nijmegen, The Netherlands
³ NIKHEF, Science Park Amsterdam, 1098, XG Amsterdam The Netherlands
⁴ Netherlands Institute of Radio Astronomy (ASTRON), Postbus 2, 7990, AA Dwingeloo The Netherland
⁵ KVI-CART, University Groningen, P.O. Box 72, 9700, AB Groningen The Netherland
⁶ Department of Astrophysical Sciences, Princeton University, Princeton NJ 08544 USA
⁷ Interuniversity Institute for High-Energy, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels Belgium
⁸ Department of Astrophysical Sciences, Princeton University, SLinnéuniversitete, Växjö,, Germany
⁹ DESY, Platanenallee 6, 15738, Zeuthen Belgium
¹⁰ Humboldt-Universität zu Berlin, Institut für Physik, Newtonstr, 15,12489, Berlin Germany

^★ e-mail: kmulrey@vub.be, funded by ERC No 640130

Published online: 24 September 2019

Abstract

The LOw-Frequency ARray (LOFAR) telescope measures radio emission from air showers. In order to interpret the data, an absolute, frequency dependent calibration is required. Due to a growing need for a better understanding of the measured frequency spectrum, we revisit the calibration of the LOFAR antennas in the range of 30—80 MHz. Using the galactic radio emission and a detailed model of the LOFAR signal chain, we find a calibration that provides an absolute energy scale and allows us to study frequency dependent features in measured air shower signals.