Analysis of the movement model of a spacecraft in earth orbit

The implementation of spacecraft motion models under real-time navigation module operation faces fundamental limitations associated with the need to balance computational accuracy and available processing power. The simultaneous execution of parallel tasks – such as processing navigation measurements, determining object coordinates via GNSS signals, noise filtering, data conversion, and archiving – requires algorithm optimization to minimize delays and resource consumption. Under these constraints, classical high-precision models based on complex differential equations or the inclusion of multiple perturbing factors become impractical due to their computational intensity. The motion model proposed in this study, integrated into navigation modules produced by JSC “KB NAVIS”, demonstrates an effective compromise: it retains sufficient trajectory prediction accuracy while adapting to hardware platform limitations. The model combines kinematic equations with adjustments accounting for primary dynamic effects (e.g., gravitational anomalies, atmospheric drag, solar and lunar gravitational influences, solar radiation pressure) but eliminates redundant calculations typical of full-scale simulations. Successful real-world testing proves that this approach can serve as a foundation for further development of navigation algorithms, particularly for small spacecraft with limited resources. The article presents the physical and mathematical formulation of the spacecraft state prediction problem, enabling a deeper understanding of how various factors affect navigation accuracy. The concluding section provides results from parameter deviation simulations and data from actual flight tests, confirming the feasibility and necessity of accounting for all parameters to achieve high navigation precision. The compiled dataset serves as an informational basis for configuring the prediction algorithm according to specific accuracy requirements.