@article{39c3a9aef8a548cd99115c7cb86674ce,
title = "The effect of the atmospheric refractive index on the radio signal of extensive air showers using Global Data Assimilation System (GDAS)",
abstract = "One of the major systematic uncertainties in the measurement of Xmax from radio emission of EAS arises from variations of the refractive index in the atmosphere. The refractive index n varies with temperature, humidity and pressure, and the variations can be on the order of 10% for (n-1) at a given altitude. The effect of a varying refractive index on Xmax measurements is evaluated using CoREAS: a microscopic simulation of the radio emission from the individual particles in the cascade simulated with CORSIKA. We discuss the resulting offsets in Xmax for different frequency regimes, and compare them to a simple physical model. Under typical circumstances, the offsets in Xmax range from 4-11 g/cm2 for the 30-80 MHz frequency band. Therefore, for precise measurements it is required to include atmospheric data at the time and place of observation of the air shower into the simulations. The aim is to implement this in the next version of CoREAS/CORSIKA using the Global Data Assimilation System (GDAS), a global atmospheric model based on meteorological measurements and numerical weather predictions. This can then be used to re-evaluate the air shower measurements of the LOFAR radio telescope.",
author = "A. Corstanje and P. Mitra and A. Bonardi and S. Buitink and H. Falcke and Hare, {B. M.} and H{\"o}randel, {J. R.} and K. Mulrey and A. Nelles and Rachen, {J. P.} and L. Rossetto and P. Schellart and O. Scholten and {Ter Veen}, S. and S. Thoudam and Trinh, {T. N.G.} and T. Winchen",
note = "Funding Information: The LOFAR cosmic ray key science project acknowledges funding from an Advanced Grant of the European Research Council (FP/2007-2013) / ERC Grant Agreement no 227610. The project has also received funding from the European Research Council (ERC) under the European Union{\textquoteright}s Horizon 2020 research and innovation program (grant agreement No 640130). We furthermore acknowledge financial support from FOM, (FOM-project 12PR304) and NWO (VENI grant 639-041-130). AN is supported by the DFG (research fellowship NE 2031/1-1). LOFAR, the Low Frequency Array designed and constructed by ASTRON, has facilities in several countries, that are owned by various parties (each with their own funding sources), and that are collectively operated by the International LOFAR Telescope foundation under a joint scientific policy. Publisher Copyright: {\textcopyright} Copyright owned by the author(s) under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives 4.0 International License (CC BY-NC-ND 4.0).; 35th International Cosmic Ray Conference, ICRC 2017 ; Conference date: 10-07-2017 Through 20-07-2017",
year = "2017",
language = "British English",
journal = "Proceedings of Science",
issn = "1824-8039",
publisher = "Sissa Medialab Srl",
}