Abstract
We examine the influence of the lunar gravity model on the orbit determination (OD) of a lunar orbiter operating in a 100 km high, lunar polar orbit. Doppler and sequential range measurements by three Deep Space Network antennas and one Korea Deep Space Antenna were used. For measurement simulation and OD analysis, STK11 and ODTK6 were utilized. GLGM2, LP100K, LP150Q, GRAIL420A, and GRAIL660B were used for investigation of lunar gravity model selection effect. OD results were assessed by position and velocity uncertainties with error covariance and an external orbit comparison using simulated true orbit. The effect of the lunar gravity models on the long-term OD, degree and order level, measurement-acquisition condition, and lunar altitude was investigated. For efficiency verification, computational times for the five lunar gravity models were compared. Results showed that significant improvements to OD accuracy are observed by applying a GRAIL-based model; however, applying a full order and degree gravity modeling is not always the best strategy, owing to the computational burden. Consequently, we consider that OD using GRAIL660B with 70 × 70 degree and order is the most efficient strategy for mission preanalysis. This study provides useful guideline for KPLO OD analysis during nominal mission operation.
Highlights
IntroductionThe Korea Pathfinder Lunar Orbiter (KPLO) is being developed by the Korea Aerospace Research Institute (KARI), with the nominal mission of operating in a lunar polar orbit at an altitude of 100 km for one year
Korea’s first lunar exploration program was launched in 2016
We examine the influence of the lunar gravity model on the orbit determination (OD) of a lunar orbiter operating in a 100 km high, lunar polar orbit
Summary
The Korea Pathfinder Lunar Orbiter (KPLO) is being developed by the Korea Aerospace Research Institute (KARI), with the nominal mission of operating in a lunar polar orbit at an altitude of 100 km for one year. For the successful operation of KPLO, development of a flight dynamics system for spacecraft navigation is essential. Orbit propagation (OP) and orbit determination (OD) are an important procedure of lunar orbiter flight dynamics operation. The orbit prediction procedure for mission planning and payload operation is associated with the OP and OD performance. Lunar gravity is a major factor regarding lunar orbiter dynamics, making the selection of a lunar gravity model critical for improved orbit accuracy and effective mission operation. For OD of KPLO mission, sequential orbit estimation using an extended Kalman filter (EKF) and a backward smoother and batch estimation using least-squares filter are considered and an accurate lunar gravity modeling has a big influence on OD performance of both filters
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
