ITU-R - International Telecommunication Union/ITU Radiocommunication Sector
适用范围
This Recommendation contains a method for predicting basic transmission loss in the frequency range 125-15 500 MHz for aeronautical and satellite services. The method uses an interpolation method on basic transmission loss data from sets of curves. These sets of curves are valid for ground-air@ ground-satellite@ air-air@ air-satellite@ and satellite-satellite links. The only data needed for this method are the distance between antennas@ the heights of the antennas above mean sea level@ the frequency@ and the time percentage. This Recommendation@ also@ gives the calculations for the expected protection ratio or wanted-to-unwanted signal ratio exceeded at the receiver for at least 95% of the time@ R (0.95). This calculation requires the following additional data for both the wanted and unwanted signals: the transmitted power@ the gain of transmitting antenna@ and the gain of receiving antenna.