About '68 or '69 one of 205 Sqn's Shackletons in Singapore was fitted with an infra red detector.Some trials were done to see if it could locate insurgents in the jungle at night by detecting their cooking fires. As I recall, some Gurkhas were up in Malaya tasked with setting up " targets". The only trial I was due to fly on was cancelled for some reason, and I have no knowledge how succesful the trials were.