ИСТИНА

Tests of general relativity using Earth-orbiting satellites are a frontier in experimental gravitation. A serious difficulty in such experiments is to accurately extract a useful effect, such as the gravitational frequency shift caused by a gravitational potential difference, from the vast amount of accompanying effects due to kinematics, propagation media, instrumental biases etc. affecting the signals sent to and from spacecrafts. For an Earth-orbiting satellite these effects include: the gravitational redshift (up to $\sim10^{-9}$ in relative frequency), non-relativistic Doppler shift ($\sim10^{-5}$), relativistic Doppler shift ($\sim10^{-13}-10^{-10}$), ionospheric and tropospheric effects ($10^{-16}-10^{-12}$), drift of atomic clocks (up to $10^{-13}$/day depending on the clock type), various instrumental effects -- magnetic, temperature sensitivities etc. In this talk we'll present results of our theoretical analysis of these effects and also some original approaches to accounting for them in satellite relativistic gravitational experiments.