Determination of spacecraft antenna directivity pattern with the use of an Earth-based station

The problem of defining characteristics of the spacecraft antenna directivity pattern is considered in the paper. The solution of the problem will make it possible to estimate changes of antenna parameters with time. A method of defining the spacecraft antenna directivity pattern with the use of the earth-based data receiving stations is proposed for solving the problem. The results of simulation modeling of distribution of electromagnetic radiation over the Earth's surface for different routes of flight are presented in the paper. These results show the possibility of using an earth-based data receiving station for the construction of the spacecraft antenna directivity pattern. An algorithm of calculating parts of the direction characteristic with their subsequent integration is given in the article. The conditions limiting the accuracy of the proposed method as well as the ways of speeding up the construction of the spacecraft antenna directivity pattern are determined.  Approbation of the proposed method through the example of the antenna of the small spacecraft “AIST-2D” is discussed. The directivity pattern of the antenna of the radio data link for transmitting target information of the satellite was constructed for this purpose and characteristic parts of the antenna directivity pattern are defined. The results of the comparative experiment with changes in the antenna radiation direction and definition of changes in information reception characteristics are presented.