Abstract: Provided are a method for maintaining Walker constellation formation and a terminal device. The method comprises: determining a first offset amount of each satellite within a simulation time period according to parameters of a Walker constellation; performing first offset on each satellite according to the first offset amount to obtain a Walker constellation after the first offset; determining a second offset amount of each satellite within the simulation time period according to parameters of the Walker constellation after the first offset; and superimposing the first offset amount and the second offset amount, and performing second offset on each satellite so as to maintain the formation of the Walker constellation.

Abstract: The disclosure describes a low-orbit satellite deorbit control method and system based on a particle swarm algorithm. The method includes: constructing an objective function according to a position parameter and a perturbation acceleration of each of particles in a particle swarm as well as a preset Lagrangian multiplier and a penalty factor; determining an objective fitness of each particle and a population fitness of the particle swarm based on the objective function, updating the position parameter and the velocity of each particle, and obtaining a population optimal fitness at a maximum number of iterations; updating the Lagrangian multiplier and the penalty factor according to the population optimal fitness, comparing the objective deviation value with a preset convergence condition, and determining an objective population fitness and an objective position parameter according to a comparison result to obtain an objective deorbit mode.

Abstract: Provided are a method for maintaining Walker constellation formation and a terminal device. The method comprises: determining a first offset amount of each satellite within a simulation time period according to parameters of a Walker constellation; performing first offset on each satellite according to the first offset amount to obtain a Walker constellation after the first offset; determining a second offset amount of each satellite within the simulation time period according to parameters of the Walker constellation after the first offset; and superimposing the first offset amount and the second offset amount, and performing second offset on each satellite so as to maintain the formation of the Walker constellation.

Abstract: The disclosure describes a low-orbit satellite deorbit control method and system based on a particle swarm algorithm. The method includes: constructing an objective function according to a position parameter and a perturbation acceleration of each of particles in a particle swarm as well as a preset Lagrangian multiplier and a penalty factor; determining an objective fitness of each particle and a population fitness of the particle swarm based on the objective function, updating the position parameter and the velocity of each particle, and obtaining a population optimal fitness at a maximum number of iterations; updating the Lagrangian multiplier and the penalty factor according to the population optimal fitness, comparing the objective deviation value with a preset convergence condition, and determining an objective population fitness and an objective position parameter according to a comparison result to obtain an objective deorbit mode.

Abstract: Provided is a method and system of evaluating a constellation spare strategy based on a stochastic time Petri net, which is applied in the technical field of constellation operation management. The method comprises: constructing a single satellite STPN model and an orbital plane STPN model, and establishing a navigation constellation STPN model that includes multiple spare strategies according to the single satellite STPN model and the orbital plane STPN model; establishing an availability model according to the number of malfunctioning satellites and the constellation value (CV) in the navigation constellation STPN model, and establishing a cost model according to operating costs of the navigation constellation STPN model; and evaluating the navigation constellation STPN model using the availability model and the cost model, and determining a target spare strategy from the multiple spare strategies according to an evaluation result.