CNS for Long Range Unmanned Surface Vessels

Long-Range Unmanned Surface Vessels (LRUSVs) must maintain accurate knowledge of position when GPS is degraded, denied, or spoofed. Trex proposes to develop a Celestial Navigation System (CNS) that operates based on the Angles-Only Navigation (AON) method (U.S. Patents 9,217,643B1, and 11,079,234B2) without input from GPS. CNS provides high accuracy (25m) position updates to the onboard INS day and night, including during the “Midnight Hole” when LEO satellites are not sun-illuminated. CNS has a small topside volume of 0.04m3 suitable for a 40-foot boat. In the Phase-I program, analyses of optimal sensor spectral band, radiometry, availability, and error budget will be conducted.  Position error will be estimated using a software tool, which simulates navigation subsystem performance using realistic models for LRUSV dynamics and measurement errors of the tactical grade IMU and an error model of the Celestial Navigator. A field demonstration for imaging stars and satellites during daytime will be performed. High accuracy position determination during the “Midnight Hole” will be field demonstrated. A Phase-II prototype preliminary design and Phase-II plan will be developed. Trex will leverage significant proven expertise in celestial navigation (>20 years). The final CNS design will meet or exceed all system requirements including size, weight, power, and cost expectations.