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Nançay Decameter Array (NDA) Jupiter Juno-Nançay data collection

Monday 13 March 2023, by Baptiste Cecconi

This data collection is composed of daily decametric observations of Jupiter acquired by the Nançay Decameter Array (NDA) with its Juno-Nançay (JunoN) receiver at the Observatoire Radioastronomique de Nançay (ORN) in Nançay, France.

Link to data

NB: at this time, the access is limited to April 2021 data.


Decametric radio observation from Nançay Decameter Array (NDA) (Lamy et al. 2017). The NDA at the Observatoire Radioastronomique de Nancay (ORN) is a phased array of 144 "Teepee" helicoidal antenna, half of which being Right Handed (RH) polarized and the other half being Left Handed (LH) polarized. Four receivers are currently connected to the NDA, sampling data in spectral ranges within 5 to 80 MHz.

This collection covers the Juno-Nançay (JunoN) high resolution receiver. The JunoN data products are not covering the full duty cycle of the original observation schedule of the receiver, but contains selected excerpts at medium and high resolution, when radio signals of interest are detected. The current section is done by a human operator.


Data format

The Juno-Nançay data files are distributed in their raw binary format (see Cecconi et al. 2022), the so-called ECube developed by the ORN team, and also used for the NewRoutine and Mefisto raw data.

Directory structure

The directory structure is built with yearly and monthly subdirectories.

File naming convention
File names are composed from the start date and time of the data product, the recording mode and an extension: YYYYMMDD_HHMMSS_extractM.EXT, where YYYYMMDD is the start calendar date (year, month, day), HHMMSS is the start time (hour, minute, second), M is the mode (1 or 2) and EXT is the file type (.dat or .txt).

Each data product is composed of two files: the data file (.dat extension) and an association description file (.txt extension).

Two data recording modes are available:

  • extract1: Medium resolution (84 ms, 12.2 kHz)
  • extract2: High resolution (2.6 ms, 3 kHz)

Coverage and sampling

  • Time range: 2016-06-26 to now
  • Time resolution: 84 ms or 2.6 ms
  • Spectral range: 6.25 to 25 MHz
  • Spectral sampling step: 12.2 kHz or 3 kHz
  • Target: Jupiter, the Sun


The authors acknowledge the Nançay Radio Observatory (UAR 704-CNRS, supported by Université d’Orléans, OSUC, and Région Centre in France) for providing access to NDA observations.

BC was also supported by PADC and EPN2024-RI. The Europlanet 2024 Research Infrastructure (EPN2024-RI) project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 871149.


Any question or request should be addressed to contact.maser@obspm.fr


  • Lamy, L., P. Zarka, B. Cecconi, L. Klein, S. Masson, L. Denis & A. Coffre (2017). 1977–2017: 40 years of decametric observations of Jupiter and the Sun with the Nançay Decameter Array, in Planetary Radio Emissions VIII, edited by G. Fischer et al., Austrian Academy of Sciences press, Vienna, 455–466. https://doi.org/10.1553/PRE8s455
  • Cecconi, B., L. Lamy, P. Renaud, A. Loh, A. Coffre & L. Denis. (2022). ORN NDA JunoN EDR Dataset Specification. Version 1.0. PADC/CDN. https://doi.org/10.25935/2Q7F-Q189

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