Gives methods of measurement applicable to satellite earth station systems using digital modulation. The object is to provide methods of measurement for assessing the essential properties of satellite earth station systems as well as the associated sub-systems. Where measurements common to terrestrial radio-relay and satellite earth station systems are required, reference is made to the appropriate section. In such cases, only those special aspects of the measurement appropriate to satellite earth station systems are described. Where parameters or methods of measurement are applicable only to satellite earth station systems, they are fully described within the appropriate sections of this part.