Radio and photographic observations of artificial satellites

Methods of photographic, radio and radar observation of satellites are discussed, together with methods of analysing these observations. The results of analysis yield information about the orbit of the satellite, and hence about effects of gravitation, atmospheric drag, and radiation pressure on the orbit. Radio observation also gives information about the effect of the ionosphere on radio waves. Although the early promise of this method of ionospheric investigation has not yet been realized, it is to be expected that it will be of considerable importance in the future. Some observations and photographs are presented and discussed. 51 references.