1、Op. ITU-R 23-6 1 OPINION ITU-R 23-6* OBSERVATIONS NEEDED TO PROVIDE BASIC INDICES FOR IONOSPHERIC PROPAGATION (1966-1970-1974-1982-1986-199.5-1999) The ITU Radiocommunication Assembly, considering a) that the 12-month running mean sunspot number R12 or alternatively the 12-month running mean value o
2、f , the 2800 MHz solar radio noise flux (i.e. 12) be adopted as the preferred index to be used for predicting monthly median values of foF2 and M(3000)F2 over all time scales: substantially equivalent results should be obtainable by the use of either of these indices; b) that 12 be adopted as the pr
3、eferred index to be used for predicting monthly median values of foE and foFl over all time scales, is of the opinion 1 that the Sunspot Index Data Centre (SIDC) sponsored by the Observatoire Royal de Belgique and the Federation of Astronomical and Geophysical Data Analysis Services (FAGS) be encour
4、aged to continue determination and distribution of the international relative sunspot numbers; 2 that the National Research Council (NRC), Penticton (Canada) should be encouraged to continue the necessary solar radio-noise flux measurements. * The Director of the Radiocommunication Bureau is requested to bring this Opinion to the attention of SIDC, NRC, the International Union of Radio Science (URSI) and FAGS. COPYRIGHT International Telecommunications Union/ITU RadiocommunicationsLicensed by Information Handling Services
