Maintaining Repeat Ground Track of Low Earth Orbit Satellite

Low Earth Orbit (LEO) satellites are designed to have orbital characteristics such as sun-synchronous orbit, frozen orbit, and repeat ground track depending on the mission of the satellite and the performance of the payload (e.g. camera, radar). Among them, the repeat ground track is useful when periodically observing a specific area. However, LEO satellites are affected by the Earth’s atmospheric drag and their altitude decreases. As a result, the ground track of the satellite drifts from the reference ground track. Also, since Earth’s atmospheric density is affected by solar activity, the satellite’s altitude does not decrease uniformly. In this study, a repeat ground track maintenance simulation is performed considering solar activity. The mean orbital elements obtained through the simulation are converted into osculating orbital elements to compare and analyze the differences.