Separation of Ambient Radio Noise and Radio Signals Received via Ionospheric Propagation
Systems for atmospheric research and wireless communication use the High Frequency (HF) radio spectrum. At these frequencies, typically up to 20 MHz, the ambient electromagnetic noise is stronger than the noise generated by the receiver itself, thereby limiting the sensitivity of the instruments. Es...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-03-01
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| Series: | Atmosphere |
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| Online Access: | https://www.mdpi.com/2073-4433/14/3/529 |
| _version_ | 1827751362190901248 |
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| author | Ben A. Witvliet Rosa M. Alsina-Pagès David Altadill Erik van Maanen Geert Jan Laanstra |
| author_facet | Ben A. Witvliet Rosa M. Alsina-Pagès David Altadill Erik van Maanen Geert Jan Laanstra |
| author_sort | Ben A. Witvliet |
| collection | DOAJ |
| description | Systems for atmospheric research and wireless communication use the High Frequency (HF) radio spectrum. At these frequencies, typically up to 20 MHz, the ambient electromagnetic noise is stronger than the noise generated by the receiver itself, thereby limiting the sensitivity of the instruments. Especially in urban areas, the noise level is high. In remote rural environments, where artificial noise sources are absent, a much lower noise level is observed. It has been shown that this noise arrives via ionospheric propagation and consists of impulsive noise from lightning and a background component that resembles additive white Gaussian noise. To establish the absolute field strength of this background noise component, a direction- and polarization-agnostic antenna is realized by adding the power of two orthogonal antenna elements in the digital domain. To suppress radio signals arriving via ionospheric propagation—of which the spectral and temporal aspects are not known a priori—a novel adaptive filter is demonstrated that separates the background noise from the radio signals in the joint frequency-time domain. This method is demonstrated using measurements from a polarimetric experiment on 7 MHz in a remote rural area in Catalonia. The results are submitted to the International Telecommunication Union for the validation of ambient noise models. |
| first_indexed | 2024-03-11T06:56:06Z |
| format | Article |
| id | doaj.art-0515b721fd5c455e8a4bcfa7ba696d79 |
| institution | Directory Open Access Journal |
| issn | 2073-4433 |
| language | English |
| last_indexed | 2024-03-11T06:56:06Z |
| publishDate | 2023-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Atmosphere |
| spelling | doaj.art-0515b721fd5c455e8a4bcfa7ba696d792023-11-17T09:33:00ZengMDPI AGAtmosphere2073-44332023-03-0114352910.3390/atmos14030529Separation of Ambient Radio Noise and Radio Signals Received via Ionospheric PropagationBen A. Witvliet0Rosa M. Alsina-Pagès1David Altadill2Erik van Maanen3Geert Jan Laanstra4Radio Systems, Faculty of EEMCS, University of Twente, Drienerlolaan 5, 7522 NB Enschede, The NetherlandsHER—Human Environment Research, La Salle—URL, c/Quatre Camins, 30, 08022 Barcelona, SpainEbro Observatory, Universitat Ramon Llull, Calle Observatori 3-A, 43520 Roquetes, SpainAuthority for Digital Infrastructure, Ministry of Economic Affairs and Climate, Emmalaan 1, 9726 AH Groningen, The NetherlandsData Management and Biometrics, Faculty of EEMCS, University of Twente, Drienerlolaan 5, 7522 NB Enschede, The NetherlandsSystems for atmospheric research and wireless communication use the High Frequency (HF) radio spectrum. At these frequencies, typically up to 20 MHz, the ambient electromagnetic noise is stronger than the noise generated by the receiver itself, thereby limiting the sensitivity of the instruments. Especially in urban areas, the noise level is high. In remote rural environments, where artificial noise sources are absent, a much lower noise level is observed. It has been shown that this noise arrives via ionospheric propagation and consists of impulsive noise from lightning and a background component that resembles additive white Gaussian noise. To establish the absolute field strength of this background noise component, a direction- and polarization-agnostic antenna is realized by adding the power of two orthogonal antenna elements in the digital domain. To suppress radio signals arriving via ionospheric propagation—of which the spectral and temporal aspects are not known a priori—a novel adaptive filter is demonstrated that separates the background noise from the radio signals in the joint frequency-time domain. This method is demonstrated using measurements from a polarimetric experiment on 7 MHz in a remote rural area in Catalonia. The results are submitted to the International Telecommunication Union for the validation of ambient noise models.https://www.mdpi.com/2073-4433/14/3/529ionosphereelectromagnetic noisepropagationadaptive filterhigh frequencyNear Vertical Incident Skywave |
| spellingShingle | Ben A. Witvliet Rosa M. Alsina-Pagès David Altadill Erik van Maanen Geert Jan Laanstra Separation of Ambient Radio Noise and Radio Signals Received via Ionospheric Propagation Atmosphere ionosphere electromagnetic noise propagation adaptive filter high frequency Near Vertical Incident Skywave |
| title | Separation of Ambient Radio Noise and Radio Signals Received via Ionospheric Propagation |
| title_full | Separation of Ambient Radio Noise and Radio Signals Received via Ionospheric Propagation |
| title_fullStr | Separation of Ambient Radio Noise and Radio Signals Received via Ionospheric Propagation |
| title_full_unstemmed | Separation of Ambient Radio Noise and Radio Signals Received via Ionospheric Propagation |
| title_short | Separation of Ambient Radio Noise and Radio Signals Received via Ionospheric Propagation |
| title_sort | separation of ambient radio noise and radio signals received via ionospheric propagation |
| topic | ionosphere electromagnetic noise propagation adaptive filter high frequency Near Vertical Incident Skywave |
| url | https://www.mdpi.com/2073-4433/14/3/529 |
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