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Coverage analysis is an essential process when designing a satellite constellation, and the variations of global revisit characteristics are usually elusive in discontinuous coverage problems. In dealing with this, a general method for analyzing the global revisit characteristics of constellations with repeating ground track orbits is proposed in this paper. Firstly, a two-dimensional map based analytical model for the point coverage of constellations is introduced. Then, the variations of revisit characteristics along both the parallel and meridian are analyzed based on the presented analytical model. Finally, numerical examples are carried out. On the one hand, the proposed analytical model for point coverage is demonstrated to be of high precision. On the other hand, all possible positions where the discontinuous changes of revisit characteristics occur can be analytically obtained, which can reveal the discontinuous variations of revisit characteristics along both the parallel and meridian, and can also ensure that all possible global or regional revisit characteristics are counted for a given constellation. The proposed method can contribute to constellation design and coverage performance analysis. • An analytical model for the coverage calculation of satellite constellations is developed. • Conditions for the appearance of the discontinuous changes of global revisit characteristics are deduced analytically. • Variations of the revisit characteristics of satellite constellations along both the parallel and meridian are revealed. [ABSTRACT FROM AUTHOR]

• A design model of hybrid constellations for Earth discontinuous coverage is established. • An analytical method for coverage analysis of hybrid constellations is proposed. • The superiority of hybrid constellations is demonstrated. This paper mainly deals with the configuration design of hybrid constellations for Earth discontinuous coverage. Firstly, a general design model of the hybrid constellation with synchronous orbital precession and multiple repeating ground tracks is developed. Then, to cope with the massive coverage calculation during the constellation design process, an analytical method for rapid coverage analysis of hybrid constellations is proposed. Finally, numerical examples are carried out, and several hybrid constellation design cases are proposed. Results indicate that the proposed coverage analysis method is demonstrated to be of high precision, and the designed hybrid constellations can achieve superior coverage performance compared with conventional Walker constellations. This research can be conducive to hybrid constellations design and Earth discontinuous coverage analysis. [ABSTRACT FROM AUTHOR]