A Subjective Method of Measuring Radio Noise

Various methods of measuring radio noise are described, and an account is given of a subjective method which was developed during the last war to obtain data quickly from a large number of locations. It was necessary to make use of simple equipment capable of being operated by personnel having little experience of radio measurements, and, with this object in view, experiments were conducted which demonstrated the efficacy of the subjective method. The equipment described is capable of measuring to an accuracy of ± 5 db any noise level greater than 1 ¿V/m over the frequency range 2.5¿20 Mc/s. The arrangements for observing, transmitting, collecting and analysing the data are briefly described.