Self-Contained Positioning Systems in GPS-Denied Operations: A Comparative Assessment of Inertial and Celestial Navigation

The vulnerability of satellite-based positioning to electronic warfare has intensified the need for autonomous navigation systems that do not rely on external radio-frequency signals [۱]. This paper provides a comprehensive comparative assessment of two self-contained positioning technologies: Inertial Navigation Systems (INS) and Celestial Navigation (CN). INS determines position, velocity, and attitude through the dead-reckoning integration of accelerometer and gyroscope measurements, offering continuous high-rate outputs but suffering from unbounded error accumulation over time [۴,۵]. Conversely, celestial navigation employs optical observations of stars, planets, and pulsars to obtain absolute attitude and position fixes with zero long-term drift, yet its performance is constrained by atmospheric conditions and sensor complexity [۶,۷]. This study derives the fundamental mathematical formulations for both methods, analyzes their primary error sources including Schuler oscillations and bias instability [۸,۲۰], and evaluates their operational performance in GPS-denied environments across air, land, sea, and space domains. Recent technological advances, including MEMS-based inertial sensors [۹], autonomous star trackers with lost-in-space algorithms [۱۰,۱۶], and X-ray pulsar timing [۱۱,۱۷], are critically reviewed. A detailed comparative assessment based on accuracy, availability, environmental dependence, computational load, and operational complexity is presented [۱۴,۱۸]. The results indicate that while neither technology alone can fulfill all mission requirements, their synergistic integration, where INS provides short-term continuity and celestial observations periodically reset accumulated drift via an Extended Kalman Filter [۱۵,۲۰], offers a robust, infrastructure-independent navigation solution for long-endurance aerospace and defense platforms. This comparative assessment ultimately serves as a practical reference for system architects and mission planners, offering clear criteria for selecting, fusing, and implementing these autonomous navigation technologies to ensure resilient PNT performance in future electronic warfare scenarios.

کلیدواژه ها:

Inertial Navigation System (INS) ، Celestial Navigation ، Star Tracker ، Pulsar Navigation ، GPS-Denied ، Attitude Determination ، Sensor Fusion