I have just added digitalised transparencies I took in 1987 of my former ROC Post in Knockholt, Kent, England. The post was part of the United Kingdom Warning & Monitoring Organisation (UKWMO) which existed during the Cold War to warn of imminent nuclear attack on the United Kingdom, to plot nuclear bursts, whether they were air or ground bursts* determined using the Ground Zero Indicator (GZI), calculating blast using an instrument that measured over-pressure called the Bomb Power Indicator (BPI); monitoring fallout using the Field Survey Meter (FSM) later replaced by the Portable Dose Rate Meter (PDRM2).

Air bursts produce more heat & blast, but much less ionising radiation distributed as nuclear fallout than ground bursts.