[논문]Development of Kinematic Ephemeris Generator for Korea Pathfinder Lunar Orbiter (KPLO)

Song, Min-Sup; Park, Sang-Young; Kim, Youngkwang; Yim, Jo Ryeong

doi:10.5140/jass.2020.37.3.199

Development of Kinematic Ephemeris Generator for Korea Pathfinder Lunar Orbiter (KPLO) 원문보기

Journal of astronomy and space sciences, v.37 no.3, 2020년, pp.199 - 208

Song, Min-Sup (Astrodynamics and Control Lab., Department of Astronomy, Yonsei University) , Park, Sang-Young (Astrodynamics and Control Lab., Department of Astronomy, Yonsei University) , Kim, Youngkwang (Astrodynamics and Control Lab., Department of Astronomy, Yonsei University) , Yim, Jo Ryeong (KPLO Mission and System Team, Korea Aerospace Research Institute)

Abstract ▼ AI-Helper

This paper presents a kinematic ephemeris generator for Korea Pathfinder Lunar Orbiter (KPLO) and its performance test results. The kinematic ephemeris generator consists of a ground ephemeris compressor and an onboard ephemeris calculator. The ground ephemeris compressor has to compress desired orbit propagation data by using an interpolation method in a ground system. The onboard ephemeris calculator can generate spacecraft ephemeris and the Sun/Moon ephemeris in onboard computer of the KPLO. Among many interpolation methods, polynomial interpolation with uniform node, Chebyshev interpolation, Hermite interpolation are tested for their performances. As a result of the test, it is shown that all the methods have some cases that meet requirements but there are some performance differences. It is also confirmed that, the Chebyshev interpolation shows better performance than other methods for spacecraft ephemeris generation, and the polynomial interpolation with uniform nodes yields good performance for the Sun/Moon ephemeris generation. Based on these results, a Kinematic ephemeris generator is developed for the KPLO mission. Then, the developed ephemeris generator can find an approximating function using interpolation method considering the size and accuracy of the data to be transmitted.

주제어

표/그림 (14)

그림 Fig. 1. Structure of the kinematic ephemeris generator for the KPLO mission. KPLO, Korea Pathfinder Lunar Orbiter.
그림 Fig. 2. Ephemeris compression algorithm for spacecraft ephemeris.
그림 Fig. 3. Compression algorithm for the Sun/Moon ephemeris.
그림 Fig. 4. Onboard algorithm for calculating ephemeris.
표 Table 1. Orbit propagation conditions
표 Table 2. Test result of Spacecraft Ephemeris Generation by Polynomial interpolation with Uniform node
표 Table 3. Test result of Spacecraft Ephemeris Generation by Chebyshev interpolation
표 Table 4. Test result of Spacecraft Ephemeris Generation by Hermite interpolation
표 Table 5. Test result of Sun Ephemeris Generation by Polynomial interpolation with Uniform node
표 Table 6. Test result of Sun Ephemeris Generation by Chebyshev interpolation
표 Table 7. Test result of Sun Ephemeris Generation by Hermite interpolation
표 Table 8. Test result of Moon Ephemeris Generation by Polynomial interpolation with Uniform node
표 Table 9. Test result of Moon Ephemeris Generation by Chebyshev interpolation
표 Table 10. Test result of Moon Ephemeris Generation by Hermite interpolation

AI 본문요약
AI-Helper

* AI 자동 식별 결과로 적합하지 않은 문장이 있을 수 있으니, 이용에 유의하시기 바랍니다.

제안 방법

The former compresses the ephemeris of orbit propagation data of spacecraft and the latter compresses the ephemeris of JPL planetary ephemerides. Compressed ephemeris data on the ground system are sent to the KPLO and then the onboard ephemeris calculator calculate ephemeris of the spacecraft and the Sun/Moon using these uploaded data.
In this study, a kinematic ephemeris generator for the KPLO is developed and its performance tests are conducted. The kinematic ephemeris generator consists of two parts: a ground ephemeris compressor and an onboard ephemeris calculator.
The spacecraft ephemeris can be generated by using Polynomial interpolation with Uniform node, Chebyshev interpolation and Hermite interpolation, respectively. In this study, after testing their performances of the three interpolation methods, an appropriate interpolation is chosen and validated for the KPLO mission.
Thus, a kinematic ephemeris generator for the KPLO has to utilizes a method of interpolating the position information only. The main contribution of this study is that a kinematic ephemeris generator algorithm based on very limited conditions for the KPLO is developed and validated. The algorithm consists of a ground ephemeris compressor and an onboard ephemeris calculator.
For the KPLO mission, onboard computer must generate ephemeris data every second for the spacecraft and the Sun/Moon. Therefore, the tests were conducted by comparing the orbit propagation data (as true values) with the generated ephemeris every second. The test parameters contain maximum distance error, mean distance error, and standard deviation.

대상 데이터

In the tests, JPL planetary ephemerides DE 430 is used. Table 5, Table 6, Table 7 are the test results of the Sun ephemeris generation by using Polynomial interpolation with Uniform node, Chebyshev interpolation and Hermite interpolation, respectively.
To test the spacecraft ephemeris generation, ephemeris data which is similar to the mission orbit is required. The mission orbit is a circular polar orbit with 100km altitude. General Mission Analysis Tool (GMAT) is used to get the reference orbit by propagating orbit based on the mission orbit (NASA GSFC 2017).

이론/모형

For the Apollo missions from 1969 to 1971, coasting integration routine with Enke’s method was used to calculate the ephemeris of the spacecraft (Savely et al. 1972).
By referring these research, a KPLO ephemeris generator has been developed by using a kinematical method. The kinematic ephemeris generator is made by utilizing the ephemeris compression method of the NASA JPL plan-etary Ephemerides (Newhall 1988; Folkner et al. 2014). A kinematic ephemeris generator equipped in onboard computer of spacecraft generates spacecraft’s ephemeris at a desired time, by using uploaded information from a ground system in the Earth.
In the last step, it computes polynomial coefficients of the interpolation function at the normalized time by using ephemeris calculated in the pre-vious step. The polynomial coefficients of the interpolation function are calculated by using Vandermonde matrix.
Consequently, lower order of approximation function can be allowed which has less number of coefficients hence, small data size. The spacecraft ephemeris can be generated by using Polynomial interpolation with Uniform node, Chebyshev interpolation and Hermite interpolation, respectively. In this study, after testing their performances of the three interpolation methods, an appropriate interpolation is chosen and validated for the KPLO mission.

참고문헌 (16)

Andolz FJ, Lunar Prospector Mission Handbook (Lockheed Martin Missiles & Space, Sunnyvale, CA, 1998).
Antreasian PG, Bhat RS, Broschart SB, Chung MK, Criddle KE, et al., The twin GRAIL spacecraft into science formation at the moon, in 23rd International Symposium on Space Flight Dynamics, Pasadena, CA, 29 Oct-2 Nov 2012.
Atkinson KE, An Introduction To Numerical Analysis, 2nd ed. (John Wiley & Sons, New York, NY, 1989).
Deprit A, Pickard H, Poplarchek W, Compression of ephemerides by discrete Chebyshev approximations, NAVIGATION. 26, 1-11 (1979). https://doi.org/10.1002/j.2161-4296.1979.tb01350.x

상세보기
Folkner WM, Williams JG, Boggs DH, Park RS, Kuchynka P, The planetary and Lunar Ephemerides DE430 and DE431, IPN Progress Report 42-196 (2014).
Heath MT, Scientific Computing: An Introductory Survey, 2nd ed. (SIAM, Philadelphia, PA, 2018).
Ju G, Korean Pathfinder Lunar Orbiter (KPLO) status update, in Annual Meeting of the Lunar Exploration Analysis Group (LEAG) Conference, Columbia, MD, 10-12 Oct 2017.
Kim YR, Song YJ, Observational arc-length effect on orbit determination for Korea Pathfinder Lunar Orbiter in the earth-moon transfer phase using a sequential estimation, J. Astron. Space Sci. 36, 293-306 (2019). https://doi.org/10.5140/JASS.2019.36.4.293

원문보기 상세보기
Lee E, Kim Y, Kim M, Park SY, Development, demonstration and validation of the deep space orbit determination software using lunar prospector tracking data, J. Astron. Space Sci. 34, 213-223 (2017). https://doi.org/10.5140/JASS.2017.34.3.213

원문보기 상세보기
Mathews JH, Fink KD, Numerical Methods using MATLAB, 3rd ed. (Pearson, New Delhi, India, 1999).
NASA GSFC, General mission analysis tool (GMAT) (2017) [Internet], viewed 2020 Jul 6, available from: https://software.nasa.gov/software/GSC-17177-1
Newhall XX, Numerical representation of planetary ephemeris, Celest. Mech. 45, 305-310 (1988). https://doi.org/10.1007/BF01229014

상세보기
Savely RT, Cockrell BF, Pines S, Apollo experience report: onboard navigational and alignment software, NASA Technical Note D-6741 (1972).
Song MS, Development and performance verification of ephemeris generator for Korea pathfinder lunar orbiter, Master Thesis, Yonsei University (2019).
Stewart GW, Afternotes on Numerical Analysis (Society for Industrial and Applied Mathematics, Philadelphia, PA, 1996).
Wei E, Yan W, Jin S, Wei J, Kutoglu H, et al., Contribution of simulated space VLBI to the Chang'E-1 orbit determination and EOPs estimation, Aerosp. Sci. Technol. 46, 256-263 (2015). https://doi.org/10.1016/j.ast.2015.07.016

상세보기

내보내기 구분	파일저장 인쇄 메일전송
구성항목	기본정보 상세정보 관리번호, 논문명, 저널/프로시딩명, 저자 , 발행년, 권, 호, 시작페이지, 끝페이지, 발행기관 관리번호, 논문명, 대등논문명, 저자 , 저널/프로시딩명, 발행기관, 발행년, 발행언어, 권, 호, 시작페이지, 끝페이지, ISBN, ISSN, 주제분야, 키워드, 초록(한글), 초록(영문), 저자(소속기관)
저장형식	Text(ASCII format) Excel format RefWorks Direct Export RIS format (for Reference Manager, ProCite, EndNote), Scholar's Aids, Mendeley
메일정보	받는사람 (필수) @ 보내는사람 (선택) @ 제목 내용 KISTI 검색결과 이메일 서비스
안내	총 건의 자료가 검색되었습니다. 다운받으실 자료의 인덱스를 입력하세요. (1-10,000) 검색결과의 순서대로 최대 10,000건 까지 다운로드가 가능합니다. 데이타가 많을 경우 속도가 느려질 수 있습니다.(최대 2~3분 소요) 다운로드 파일은 UTF-8 형태로 저장됩니다. 파일의 내용이 제대로 보이지 않을실 때는 웹브라우저 상단의 보기 -> 인코딩 -> 자동선택 여부를 확인하십시오. ~ Text(ASCII format) Excel format

연합인증