An in-situ calibration of a logarithmic periodic dipole antenna with a frequency coverage of 30MHz to 80MHz is performed. Such antennas are part of a radio station system used for detection of cosmic ray induced air showers at the Engineering Radio Array of the Pierre Auger Observatory, the so-called Auger Engineering Radio Array (AERA). The directional and frequency characteristics of the broadband antenna are investigated using a remotely piloted aircraft carrying a small transmitting antenna. The antenna sensitivity is described by the vector effective length relating the measured voltage with the electric-field components perpendicular to the incoming signal direction. The horizontal and meridional components are determined with an overall uncertainty of 7.4+0.9-0.3% and 10.3+2.8-1.7% respectively. The measurement is used to correct a simulated response of the frequency and directional response of the antenna. In addition, the influence of the ground conductivity and permittivity on the antenna response is simulated. Both have a negligible influence given the ground conditions measured at the detector site. The overall uncertainties of the vector effective length components result in an uncertainty of 8.8+2.1-1.3% in the square root of the energy fluence for incoming signal directions with zenith angles smaller than 60°.
Publication Source (Journal or Book title)
Journal of Instrumentation
Aab, A., Abreu, P., Aglietta, M., Al Samarai, I., Albuquerque, I., Allekotte, I., Almela, A., Castillo, J., Alvarez-Muñiz, J., Anastasi, G., Anchordoqui, L., Andrada, B., Andringa, S., Aramo, C., Arqueros, F., Arsene, N., Asorey, H., Assis, P., Aublin, J., Avila, G., Badescu, A., Balaceanu, A., Barbato, F., Luz, R., Beatty, J., Becker, K., Bellido, J., Berat, C., Bertaina, M., Bertou, X., Biermann, P., Billoir, P., & Biteau, J. (2017). Calibration of the logarithmic-periodic dipole antenna (LPDA) radio stations at the Pierre Auger Observatory using an octocopter. Journal of Instrumentation, 12 (10) https://doi.org/10.1088/1748-0221/12/10/T10005