Link Topology and Multi-Objective Mission Flow Optimization for Remote Sensing Satellites With Inter-Layer Links and Satellite-Ground Links
Xiaoqing Zhong, Ningxuan Guo, Anshou Li, Yupeng Gong, Yuqi Wang, Ningyuan Wang, Liang Liu
Abstract
In the future Space Information Network (SIN), remote sensing satellites (RSSs) can access communication constellations (CCs) and ground stations (GSs) through inter-layer links (ILLs) and satellite-ground links (SGLs) to realize the timely transmission of large amounts of observation data. In this paper, we study the link topology of both ILLs and SGLs with different time slot durations from the perspective of each RSS based on the time-expanded graph. We propose a multi-objective mission flow optimization model to jointly achieve transmission benefits maximization, end-of-period energy maximization, and transmission wait time minimization. This model considers missions' importance differences under limited storage, energy, and link bandwidth resources. To reduce the solving complexity and solution time, we propose a Phased Multi-Objective (PMO) algorithm to solve this problem. We simulate the proposed methods in different scale SIN with practical parameters. The results show that RSS's entire orbital period can be covered by ILLs and SGLs, except for the ILLs' handover time. When the ILLs' data transmission rate is much less than the RSSs' data acquisition rate, important mission data can be transmitted in priority. When the transmission rate approaches the data acquisition rate, all observation data can be transmitted in near real-time. The proposed PMO algorithm can obtain the optimal solution in 19.1 seconds for a constellation with 500 satellites, which is much less than the 3.8-minute solution time used by other existing methods.