This paper presents relative navigation using intermittent laser-based measurement data for spacecraft flying formation that consist of two spacecrafts; namely, chief and deputy spacecrafts. The measurement data consists of the relative distance measured by a femtosecond laser, and the relative angles between the two spacecrafts. The filtering algorithms used for the relative navigation are the extended Kalman filter (EKF), unscented Kalman filter (UKF), and least squares recursive filter (LSRF). Numerical simulations reveal that the relative navigation performances of the EKF- and UKF-based relative navigation algorithms decrease in accuracy as the measurement outage period increases. However, the relative navigation performance of the UKF-based algorithm is 95 % more accurate than that of the EKF-based algorithm when the measurement outage period is 80 sec. Although the relative navigation performance of the LSRF-based relative navigation algorithm is 94 % and 370 % less accurate than those of the EKF- and UKF-based navigation algorithms, respectively, when the measurement outage period is 5 sec; the navigation error varies within a range of 4 %, even though the measurement outage period is increased. The results of this study can be applied to the design of a relative navigation strategy using the developed algorithms with laser-based measurements for spacecraft formation flying.

1. INTRODUCTION
 2. DYNAMIC MODEL
 3. LASER-BASED MEASUREMENT
 4. RELATIVE NAVIGATION ALGORITHMS
  4.1 Nonlinear Discrete-time System
  4.2 Extended Kalman Filter-Based Relative Navigation Algorithm with Intermittent Measurement
  4.3 Unscented Kalman Filter-based Relative NavigationAlgorithm with Intermittent Measurements
  4.4 Least Squares Recursive Filter-based Relative NavigationAlgorithm with Intermittent Measurements
 5. NUMERICAL SIMULATIONS AND ANALYSES
  5.1 Relative Navigation Simulations
  5.2 Numerical Results
 6. CONCLUSION
 REFERENCES

• Jongwoo Lee(Astrodynamics and Control Laboratory, Department of Astronomy, Yonsei University)
• Sang-Young Park(Astrodynamics and Control Laboratory, Department of Astronomy, Yonsei University) Corresponding Author
• Dae-Eun Kang(Astrodynamics and Control Laboratory, Department of Astronomy, Yonsei University)