that Report 322 (Geneva, 1963) was based on data obtained from a network of 16 recording stations from July 1957 to October 1961 and, with a minor revision, was reissued as Report 322-2 (Geneva, 1982)
ITU-R PI.372-5-1990 history
1990ITU-R PI.372-5-1990 Use of Data on Radio Noise - Section 6B - Radio Noise