Aiming at the challenges faced by Low Earth Orbit (LEO) constellations, such as
difficulties in cross-shell communication, complexity in global management and
control, and highly dynamic network topologies, this paper evaluates the
introduction of a Medium Earth Orbit (MEO) constellation as a management layer
to optimize the coordination and servicing of the underlying LEO constellation.
The core contributions of this work are twofold. First, a coverage performance
analysis method based on Voronoi diagrams and Delaunay triangulation is adopted
to evaluate the coverage of MEO constellations over LEO constellations. Second,
a four-dimensional multi-objective fitness function is constructed,
comprehensively considering launch cost, communication delay, coverage
performance, and space security. On this basis, a multi-objective genetic
algorithm is employed to optimize the key parameters of a Walker-type MEO
constellation, including orbital altitude, orbital plane count, and satellites
per plane. Simulation results show that, under the condition of a LEO
constellation altitude of 600 km, highly fit MEO configuration parameters are
obtained. STK simulations verify that this configuration can achieve complete
and dynamic coverage of the underlying LEO constellation. This study provides a
systematic theoretical framework and an efficient algorithmic tool for solving
the configuration optimization problem of the MEO layer in the "LEO-MEO"
architecture.