Radio Emission from Jupiter as Recorded by Juno Spacecraft and Simultaneous Earth Based Observatories

Jupiter emits radio emission of two types: thermal and non-thermal radiation. Again non-thermal radiation can be categorized into four types, viz., DIM, DAM, HOM and KOM among which Jovian DAM radiation is the only one that can be observed from Earth. The DAM has frequencies in the range 3–40 MHz. At the low frequency the earth's ionosphere is not transparent. So DAM signals bellow 10 MHz cannot be observed by earth-based radio telescopes. In contrast, there is no such limitation on frequencies in observation by spacecraft. In this paper, we have attempted to understand the latitudinal beaming of Jovian DAM radiation and also to confirm DAM generation by the electron cyclotron maser instability (CMI), a widely accepted generation mechanism. In order to re-investigate the relations between KOM / HOM / non-Io DAM components, we have made comparison of the data as derived from a simultaneous study of radio emission from Jupiter by space crafts and earth based observatories. The spacecraft Juno provided a new opportunity for observing radio emission properties of Jupiter at length. Earth-based radio observatories like Long Wavelength Array Station One (LWA1) in New Mexico, USA, and Nancay Decameter Array (NDA) in France plays an important role in this regard. We have made a comparative study of Jovian DAM by NDA and JUNO and presented results on radio burst signals received using dipole antenna during the days when the space craft Juno was in vicinity of Jupiter.