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This paper describes the statistical property of Jupiter's millisecond burst (S‐burst) beaming for Io‐related decametric (Io‐DAM) sources from a ground‐based radio telescope network. To do so, we performed simultaneous observations of Jovian Io‐DAM S‐bursts from 15 January through 4 May 2016 for a total of nine events using several radio telescopes. These radio telescopes include the Long Wavelength Array station One (LWA1) in the United States, Nançay Decameter Array (NDA) in France, and three large radio telescopes (UTR2, URAN2, and URAN3) in Ukraine. We conducted a cross‐correlation analysis of the S‐burst spectrograms in a frequency range of 10.5 to 33 MHz over effective baselines of up to 8,950 km. We found that the beaming of the S‐bursts is formed on the flashlight‐like structure within an east‐west beam width of 2.75" for Io‐A/C, 2.63" for Io‐A', and 2.75" for Io‐B/D. In parallel, the flashlight‐like beam was completely filled because the results from all usable pairs of telescopes supported this model. Hence, these beam widths directly correspond to the minimum cone thickness where a radio source emanates over large solid angles from the same direction of Jupiter, as opposed to a localized radio source emitting over small solid angles along active magnetic flux tubes that are tied to Io's orbital motion in Jupiter's rotation frame (beacon‐like structure). Additionally, this cross‐correlation technique shows a practical benefit of producing statistical profiles of S‐bursts. Plain Language Summary: In our solar system, Jupiter is second only to the Sun in its intensity as a radio source. One of the radio sources tied to Jovian auroras dominates at the decameter wavelength, exhibiting fine structures (called S‐bursts) in a timescale of milliseconds. While spacecraft equipped with a low‐frequency radio system is insufficient to capture S‐bursts in a broad frequency bandwidth and a long‐term period, Earth‐based radio telescopes offer high‐resolution observations of Jovian S‐bursts. Using five world‐class large radio telescopes in the United States, France, and Ukraine, we performed the common S‐burst observation campaign in 2016. We found that S‐burst beaming is wide enough to cover the maximum baseline of 8,950 km between radio telescopes in the United States and Ukraine. This result provides a nature of Jovian S‐burst beaming lasting on the order of the milliseconds. Key Points: S‐burst long baseline analysis was performed using five powerful radio telescopes on the groundStatistics of nine Io‐related events show that S‐burst beam is formed by a flashlight‐like beam structureThe cross‐correlation analysis can isolate the S‐burst frequency‐dependent distributions from those of the other emissions [ABSTRACT FROM AUTHOR]

The scientific focus of the future JUICE (Jupiter Icy Moons Explorer) mission is to study the Galilean moons Ganymede, Callisto and Europa as potential habitable environments, and to study the Jupiter system as an archetype for gas giants. The so-called RPWI (Radio & Plasma Wave Investigation) onboard of JUICE will investigate the plasma environment and the rich Jovian radio spectrum. The latter will be done with the RWI (Radio Wave Instrument) which consists of three orthogonal dipole antennas of 2.5 m tip-to-tip length and a pre-amplifier mounted on the magnetometer boom plus corresponding radio receivers. The usage of three antennas allows the determination of the wave polarization and the incoming wave direction, but this is only possible with a well-calibrated antenna system.In this presentation we report about the antenna calibration results from the experimental method of rheometry, in which a gold-plated, metallic scale model (1:40) of the JUICE spacecraft was immersed in a water-filled tank with a homogeneous electric field. By using at least two different suspensions of the model it was possible to derive the so-called effective length vector of each dipole, which describes the reception property of each antenna in the quasi-static frequency range. With the method of rheometry one can in principle measure the so-called open-port effective length vectors, which do not take the capacitve load (e.g. cable capacitance, input capacitance of pre-amplifier) on the antennas into account. The effective length vectors for loaded antennas can be calculated in case the antenna capacitances and the load capacitances are known. We have tested a new method to directly measure the effective length vectors for loaded ports with rheometry by introducing variable resistors, set up in parallel to each antenna port. We also compare the rheometry results with the results from numerical computer simulations with patch-grid models. [ABSTRACT FROM AUTHOR]

Type III bursts are intense, non-thermal sporadic solar radio emissions and can becharacterized by their rapid development in time and frequency in the dynamic spectrum.Produced by accelerated electron beams which propagate along open magnetic field linesduring the impulsive phase of a flare via the plasma emission mechanism and generated at thelocal electron plasma frequency fp ≃ 9√ne kHz (ne as the plasma density: number ofelectrons per volume cm−3) and/or its harmonic 2fp, their frequency ranges from ∼ 1 GHzto ∼ 20 kHz thus making them observable also by ground-based radio telescopes. Beside afast drift from high to low frequencies, bursts duration increases simultaneously as the driftrate decreases at lower frequencies. These strong relations between features and type IIIbursts are very distinct to other bursts that are accompanying the periods of solaractivities and represent an excellent candidate for pattern recognition by supervisedmachine learning. Convolutional Neural Networks (CNNs) enjoy a great success inlarge scale image and video recognition and will in the present work be used toscan as a sliding window along the time axis over a dynamic spectrum. The dataare provided by accompanied large ground based low frequency radio astronomyfacilities like UTR-2, URAN-2 or GURT as well as from space-borne observationslike STEREO/WAVES and will be stacked along the frequency axis, covering anoverall frequency range from 0.1 MHz up to 80 MHz, to extract type III features. [ABSTRACT FROM AUTHOR]