Strapdown integrated navigation system/celestial navigation system(SINS/CNS) integrated navigation positioning
system is widely used in unmanned aerial vehicles(UAVs) with high altitude and long range. CNS gets the position
information using iteration calculation, so traditional SINS/CNS positioning algorithm setting the position error between
INS and CNS as measurement can introduce positioning calculation error inevitably. The model of altitude azimuth, platform
error angles and horizontal position is designed. Furthermore, the SINS/CNS tightly integrated algorithm using unscented
Kalman filter(UKF) is designed, in which CNS altitude azimuth is the measurement information. The simulation results
show that SINS/CNS algorithm can calculate the position using one star information, and the precision which reaches 100m
using three stars is improved effectively.