PLANETARY LOW-FREQUENCY RADIO ASTRONOMY WITH LARGE GROUND-BASED INSTRUMENTS

Existing (UTR-2, GMRT, VLA, Nançay Decameter Array) and emerging (LOFAR) large low-frequency radio instruments start providing unprecedented capabilities in terms of sensitivity, angular resolution, polarization measurements, or all together, opening new perspectives for planetary studies, among which the detection and study of solar system planetary lightning, the fast radio imaging of Jupiter's magnetosphere, including synchrotron emission from radiation belts as well as decameter emission from high magnetic latitudes, and the search for radio emission from the plasma environment of exoplanets. Science objectives, recent results and ongoing programs are summarized here. RFI mitigation techniques now allow to work- to some extent- in the heavily polluted low-frequency radio environment of the Earth. Ionospheric propagation effects bring strong perturbations to both the amplitude and phase of received signals, especially near solar maximum. Feasibility of VLBI observations below 40 MHz is discussed