Post Instrument Mark IIC

Post Instruments were used in the Second World War by members of the Observer Corps as an aide to assess the height, bearing and location of enemy aircraft.

This Post Instrument is fitted with a Micklethwait Height Correction attachment which, when used in conjunction with information from another observer post monitoring the same aircraft, could refine the estimate of the aircraft’s height. Information was passed to Observer Corps plotting centres and then to RAF Fighter Command so they could plot a real-time picture of German air attacks as they developed.