Empirical models of the Solar Wind : Extrapolations from the Helios & Ulysses observations back to the corona

Milan Maksimovic, LESIA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université Paris Diderot, Sorbonne Paris Cité, Meudon, France, Meudon, France and Arnaud Zaslavsky, CNRS, Observatoire de Paris, LESIA, Meudon, France