"C. Donald Bateman, the primary inventor of both GPWS and EGPWS (along with the patents underpinning both) was very much as much a safety advocate as he was an engineer."
Mr Bateman is a bonafide hero of aviation safety.
There's lot's of pilots and passengers still walking around because of his genious and technical leadership.
EGPWS added "look ahead" terrain alerting that is based, not on radar, but on terrain data and altimetry. Original GPWS, still included in EGPWS, uses radio altitude, inertial sensors and air data to provide terrain and sink rate alerts.
Terrain Following Radar (F-111, etc) was radar-based anticipation of the terrain ahead and flying close but not too close to terrain and yet stay below enemy radar.
Terrain Contour matching (Terrcom) was navigation by matching the changing radio altitude (profile) with terrain data to update and fine-tune on-board inertial navigation - used mostly by long range cruise missiles (before GPS?)