| Title: |
Probing the firn refractive index profile using antenna response |
| Authors: |
Agarwal, Sanyukta; Aguilar, J.A; Alden, Nathaniel; Ali, Shoukat; Allison, Patrick; Betts, Michael; Besson, Dave; Bishop, Abby; Botner, Olga; Bouma, Sjoerd; Buitink, Stijn; Camphyn, Ruben; Chiche, Simone; Clark, Brian; Coleman, Alan; Couberly, Kenny; De Kockere, Simon; deVries, Krijn; Deaconu, Cosmin; Giri, Pawan; Glaser, Christian; Glusenkamp, Thorsten; Hallgren, Allan; Hallmann, Steffen; Hanson, Jordan Christian; Hendricks, Bryan; Henrichs, Jakob; Heyer, Nils; Hornhuber, Christian; Huesca Santiago, Enrique; Hughes, Kaeli; Karg, Timo; Karle, Albrecht; Kelly, John; Korntheuer, Michael; Kowalski, Marek; Kravchenko, Ilya; Krebs, Ryan; Lahmann, Robert; Liu, Martin; Marsee, Matthew J; McLennan, Curtis; Mikhailova, Masha; Mulrey, Katharine; Muzio, Marco; Nelles, Anna; Novikov, Alexander; Nozdrina, Alisa; Oberla, Eric; Oeyen, Bob |
| Source: |
Journal of Glaciology ; volume 72 ; ISSN 0022-1430 1727-5652 |
| Publisher Information: |
Cambridge University Press (CUP) |
| Publication Year: |
2026 |
| Description: |
The Radio Neutrino Observatory-Greenland (RNO-G, at Summit Station) experiment comprises an extensive fat-dipole antenna array deployed into ice boreholes over an eventual area of approximately 35 km 2 . Since the RNO-G experimental sensitivity depends on the radio-frequency properties of the firn, which are known to vary laterally on sub-km distance scales and vertically on sub-meter distance scales, a technique for quickly extracting information on firn ice properties with depth ( $n(z)$ ) during drilling and deployment is desirable. Given that a dipole’s resonant wavelength is fixed by geometry, the resonant frequency $f_{res}$ (measured as an S-parameter reflection coefficient [‘ $S_{11}$ ’] minimum) scales inversely with the local refractive index, allowing a translation of a depth-dependent $S_{11}$ (z) profile into $n(z)$ . $S_{11}$ (z) data were initially taken in August 2024 using a dipole lowered into a newly drilled 98 ± 1 mm diameter, 350 m deep borehole at Summit Station, Greenland, approximately 1 km from the site of the original GISP-2 core; improved measurements were subsequently made in May 2025. We conclude that $S_{11}$ (z) data can be used to estimate $n(z)$ , on 50 cm vertical scales, at the per cent level of accuracy required by experiments such as RN0-G. |
| Document Type: |
article in journal/newspaper |
| Language: |
English |
| DOI: |
10.1017/jog.2026.10133 |
| Availability: |
https://doi.org/10.1017/jog.2026.10133; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143026101336 |
| Rights: |
http://creativecommons.org/licenses/by/4.0 |
| Accession Number: |
edsbas.5D319858 |
| Database: |
BASE |