It is with great sadness that we learned of the recent passing of John Ponsonby.
John was one of the technical pioneers at Jodrell Bank from the early 1960s onwards: he built the 'Doppler Ephemeris Machine' for planetary radar experiments and carried out one of the first (1961) radar determinations of the distance to Venus and hence the Astronomical Unit (as part of his PhD); he measured the rotation rate of Venus using radar in 1964; developed early techniques of synthetic aperture radar for imaging the Moon, and also made important early contributions to techniques of aperture synthesis including Maximum Entropy.
He spent many years designing and building a sophisticated Hydrogen Maser frequency standard at Jodrell Bank, which was used experimentally. John had a fierce intellect which he applied to a wide range of challenging problems - his hand-written one-page notes were brilliantly illuminating. He was a force to be reckoned with and an unforgettable character, and one of the true pioneers of radio and radar astronomy at Jodrell Bank.