LEO Satellite Positioning Error Compensation Method for GNSS-Resilient Environments
- 주제(키워드) LEO Satellite , LEO PNT
- 주제(DDC) 004.6
- 발행기관 아주대학교 일반대학원
- 지도교수 Jae-Hyun Kim
- 발행년도 2026
- 학위수여년월 2026. 2
- 학위명 석사
- 학과 및 전공 일반대학원 AI융합네트워크학과
- 실제URI http://www.dcollection.net/handler/ajou/000000035891
- 본문언어 한국어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
The growing interest in low Earth orbit (LEO) satellite constellations for positioning, navigation, and timing (PNT) services is driven by their lower altitude compared with conventional medium Earth orbit (MEO) Global Navigation Satellite System (GNSS) satellites, which provides higher received signal power, shorter propagation delay. These advantages make LEO satellite PNT systems strong candidates for next generation positioning, particularly in scenarios with restricted GNSS service. However, in practical LEO satellite constellations, only a subset of satellites can periodically calibrate their onboard clocks and refine orbit estimates using GNSS, while the remaining satellites rely on low cost oscillators and imperfect orbit prediction. As GNSS availability deteriorates, the clock and orbital errors of these satellites accumulate over time, directly degrading PNT accuracy. To overcome these limitations, this thesis proposes a GNSS anchored confidence weighted consensus method. In the proposed approach, LEO satellites exchange clock and position information with neighboring satellites via inter satellite links (ISLs). Satellites whose clock and orbit are corrected by GNSS act as high confidence anchors and are assigned larger weights in the consensus algorithm, so that reliable time and orbit information is gradually propagated to uncorrected satellites across the constellation. Simulation results for Walker star and Walker delta constellations, with both SCAC and TCXO clocks and various ratios of GNSS corrected LEO satellites, show that the proposed method consistently reduces the mean positioning error, 95% positioning error, and positioning error standard deviation compared with a baseline scheme without confidence weighting. Furthermore, comparable accuracy is achieved even when only a small fraction of satellites is corrected or when low cost clocks are used, indicating that the proposed method offers a practical and cost effective solution for enhancing LEO satellite PNT systems under realistic GNSS degraded conditions.
more목차
1 Introduction 1
1.1 Background and motivation 1
1.2 Contributions 3
1.3 Overview 3
2 Related works 4
2.1 LEO satellite architectures 4
2.1.1 LEO satellite constellation 4
2.1.2 LEO satellite ISL 5
2.2 Satellite positioning method 6
2.3 LEO satellite positioning error 10
2.3.1 Dilution of precision and GDOP 11
2.3.2 LEO satellite positioning error compensation 13
2.4 Resent research 14
3 Proposed positioning error compensation method 16
3.1 Scenario 16
3.1.1 LEO satellite clock error 16
3.1.2 LEO satellite orbit error 17
3.1.3 SNR Based Pseudorange Error 18
3.2 Proposed GNSS Anchored Confidence Weighted Consensus method 19
3.2.1 Local Correction States 20
3.2.2 Local Confidence Prediction 21
3.2.3 Incorporating Given GNSS Corrections 21
3.2.4 Confidence Weighted ISL Consensus method 22
4 Performance evaluation 24
4.1 Simulation environments 24
4.2 Key performance indicators 26
4.3 Results and discussion 28
5 Conclusion 38
References 40
