Doppler Phenomena in Space Communications

The Doppler phenomenon is studied under spaceflight conditions. These conditions impose restrictions, and introduce influences which otherwise are of negligible importance. Examples of undesired effects of the Doppler shift in space communications and of applications for useful purposes are given. General relations are derived for the Doppler shift which permit consideration of the space-flight conditions. These conditions, one of which is flight through ionized medium and electron clouds, cause deviations from a regular Doppler shift. The deviations can be considered as errors, or they can be measured and explored for obtaining data about electron densities in space. Evaluation of Doppler measurements in satellite tracking is considered as an example.