Hugh Griffiths is distinguished for his research in radar – in particular bistatic radar, in which the transmitter and receiver are spatially separated, and passive radar, in which the radar receiver exploits existing transmissions such as broadcast, communications or radionavigation signals. These configurations have important applications in military radar sensing in which the passive nature of the receiver is advantageous, and in the detection of stealthy targets, as well as in civil radar as demand for spectrum from all users increases.

He has pioneered this subject over several decades in undertaking some of the first experiments on passive radar, and his work and publications have stimulated further work worldwide, to the point where passive radar is now a mainstream subject. He has also made measurements of the bistatic radar scattering properties of land and sea, and of various types of target including drones, birds and humans.

Hugh received the IET A F Harvey Prize in 2012, the IEEE Picard Medal in 2017, and he was appointed OBE in 2019 for services to engineering.