Abstract :
It is possible to increase the level of ambient illumination in rooms where p.p.i.-type radar displays are used, without any apparent reduction of signal detection threshold, by the use of a narrow-band optical filter superimposed on the face of the cathode-ray tube, and the use of an illuminant complementary to the response of the tube. Experiments at the Royal Aircraft Establishment, Farnborough, have shown that it is possible, by the use of a number of illuminants lying outside the pass-band of the filter, to create an impression of white ambient lighting in which the colour discrimination of the operations room staff appears to be unimpaired. It is believed that this development will be of considerable use where it is necessary to display in the same room radar data and plotting-table information. It is also expected that an increase in the level of ambient illumination will lead to a reduction in operator fatigue.
