Address Selective Surveillance Radar
An improved Secondary Surveillance Radar system that was designed in the 1980s to overcome many of the then defects in SSR. ADSEL was developed by Cossor Electronics Limited working in conjunction with the Royal Signals and Radar Establishment (RSRE) and the Civil Aviation Authority.
Photo above taken at Matching Green, think that’s Cossor’s Rod Roper on the right
photo taken at RSRE