Radar to the planets and back

Generally, we think of radar as a technique widely used for the detection and location of man-made objects like aircraft, ships and speeding cars. Much less often do we consider the use of radar as a tool for exploring the Earth´s upper atmosphere and extraterrestrial members of the solar system. But in fact it was in the ionospheric-sounding experiments carried out just over 50 years ago that radar as we now know it has its origins