4.1 information For the calculation of the propagation mode (1) required distance, the world has been classified in terms of a radio- meteorological parameter representing clear-air anomalous propagation conditions. The percentage of time for which e these clear-air anomalous propagation conditions exist, is latitude dependent and is given by: with: is the latitude of the earth station’s location (degrees). For frequencies between 790 MHz and 60 GHz, the path centre sea level surface refractivity, is used in the N0, propagation mode (1) calculations. This can be calculated using: (12) 4.2 Minimum coordination distance for propagation modes (1) and (2) The minimum coordination distance can be calculated in two steps. First calculate distance using: dx km (13) where is given in § 4.1. e Then calculate the minimum coordination distance at any frequency, (GHz) in the range 100 MHz to 105 GHz using: f The distance from which all iterative calculations start (for both propagation mode (1) and propagation mode (2)), is the minimum coordination distance, as given in equations (14) to (19). dmin, 4.3 Maximum coordination distance for propagation mode (1) In the iterative calculation described in Appendix 1 to Annex 1, it is necessary to set an upper limit, to the dmax1, propagation mode (1) coordination distance. For frequencies less than or equal to 60 GHz and propagation paths entirely within a single Zone, the distance shall not exceed the maximum coordination distance given in Table 3 for that Zone. For mixed paths, the required distance can comprise one or more contributions from Zones A1, A2, B and C. The aggregate distance for any one zone must not exceed the value given in Table 3. The overall required distance must not exceed the value in Table 3 for the zone in the mixed path having the largest Table 3 value. Thus, a path comprising both Zones A1 and A2 must not exceed 500 km. 3 Maximum coordination distances for propagation mode (1) for frequencies below 60 GHz dmax1 Zone (km) A1 0.500 A2 0.375 B2 0.900 C2 1 200 For frequencies above 60 GHz, the maximum coordination distance, is given by: dmax1, (20) where is defined in § 1.3. p
4.1 information For the calculation of the propagation mode (1) required distance, the world has been classified in terms of a parameter representing clear-air anomalous propagation conditions. The percentage of time e for which these clear-air anomalous propagation conditions exist, is latitude dependent and is given by: with: is the latitude of the earth station’s location (degrees). For frequencies between 790 MHz and 60 GHz, the path centre sea level surface refractivity, N0, is used in the propagation mode (1) calculations. This can be calculated using: (12) 4.2 Minimum coordination distance for propagation modes (1) and (2) The minimum coordination distance can be calculated in two steps. First calculate distance dx using: km (13) where e is given in § 4.1. Then calculate the minimum coordination distance at any frequency, f (GHz) in the range 100 MHz to 105 GHz using: The distance from which all iterative calculations start (for both propagation mode (1) and propagation mode (2)), is the minimum coordination distance, dmin, as given in equations (14) to (19). 4.3 Maximum coordination distance for propagation mode (1) In the iterative calculation described in Appendix 1 to Annex 1, it is necessary to set an upper limit, dmax1, to the propagation mode (1) coordination distance. For frequencies less than or equal to 60 GHz and propagation paths entirely within a single Zone, the distance shall not exceed the maximum coordination distance given in Table 3 for that Zone. For mixed paths, the required distance can comprise one or more contributions from Zones A1, A2, B and C. The aggregate distance for any one zone must not exceed the value given in Table 3. The overall required distance must not exceed the value in Table 3 for the zone in the mixed path having the largest Table 3 value. Thus, a path comprising both Zones A1 and A2 must not exceed 500 km. 3 Maximum coordination distances for propagation mode (1) for frequencies below 60 GHz Zone dmax1 (km) A1 0.500 A2 0.375 B2 0.900 C2 1 200 For frequencies above 60 GHz, the maximum coordination distance, dmax1, is given by: (20) where p is defined in § 1.3. meteorological radio-