In this study, the precise orbit determination (POD) software is developed for optical observation. To improve the performance of the estimation algorithm, a nonlinear batch filter, based on the unscented transform (UT) that overcomes the disadvantages of the least-squares (LS) batch filter, is utilized. The LS and UT batch filter algorithms are verified through numerical simulation analysis using artificial optical measurements. We use the real optical observation data of a low Earth orbit (LEO) satellite, Cryosat-2, observed from optical wide-field patrol network (OWL-Net), to verify the performance of the POD software developed. The effects of light travel time, annual aberration, and diurnal aberration are considered as error models to correct OWL-Net data. As a result of POD, measurement residual and estimated state vector of the LS batch filter converge to the local minimum when the initial orbit error is large or the initial covariance matrix is smaller than the initial error level. However, UT batch filter converges to the global minimum, irrespective of the initial orbit error and the initial covariance matrix.

1. INTRODUCTION
2. PRECISE ORBIT DETERMINATION (POD)
    2.1 Models: Dynamic and Measurement
    2.2 Estimation Algorithm: Batch Filter Based on theUnscented Transform
3. VERIFICATION OF ALGORITHMS
    3.1 Verification of Models
    3.2 Verification of Filters
4. OWL-NET DATA APPLICATION
    4.1 POD Analysis on the Initial Orbit Error
    4.2 POD Analysis on the Initial Covariance Matrix
    4.3 POD Analysis on Observation arc Length and theNumber of Data Points
5. CONCLUSIONS
REFERENCES

• Hyewon Hwang(Department of Astronomy, Yonsei University)
• Eunji Lee(Department of Astronomy, Yonsei University)
• Sang-Young Park(Department of Astronomy, Yonsei University) Corresponding Author