유연무중단특성을가진 위성항법지상부분설계에대한고찰 한국항공대학교항공전자정보공학부 이형근

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1 유연무중단특성을가진 위성항법지상부분설계에대한고찰 한국항공대학교항공전자정보공학부 이형근

2 발표순서 현황 고찰 요소기술 구조연구 기능별점검사항 절대전리층 상대전리층 수신기 / 네트워크인터페이스 기준국유입및소실에대한재형상기능 결론

3 현황

4 GNSS 의환경변화 GLONASS SBAS L1/L5 L1/L2/L5 GPS GALILEO Beidou B1/B2/B3 G1/G2 E1/E5(a,b)/E6 주제어국 연산량 대역폭 상시기준국망 2 항공 측량 교통 교량모니터링 차량항법

5 GNSS 에서지상부분주제어국의중요성 An important benefit of GNSS is that it can provide absolute time and position information anytime anywhere To help users on wide area to generate accurate estimates on absolute time, position, and atmospheric delays, an efficient master station is required

6 GPS 지상부분의초기개형 Colorado Springs Hawaii Ascension Islands Diego Garcia Kwajalein Master Control Station (1) [Source: Monitor Station (5) Ground Antenna (3)

7 GPS 지상부분의최근개형 [Source:

8 QZSS 지상부분의개형 [Source:

9 QZSS L1 SAIF 서비스의개형 [Source: High Precision Navigation Capabilities(L1-SAIF) and Applications Using Japanese Quasi-Zenith Satellite System (QZSS), Satellite Positioning Research and Application Center, ICG WG-B Application SG Meeting, Munich, Germany, March 12, 2012]

10 MADOCA PPP 서비스의개형 - Multi-GNSS Support (GPS,GLONASS,Galileo and QZSS) - Offline/Real-Time Estimator - Precise Estimation using latest models - Reduction of Processing Time by Multi-threading - Maintainability and Portability which can run on note PC [Source:

11 MADOCA 후처리연산량 [Source: 複数 GNSS 高精度軌道時刻推定ツール MADOCA の開発, JPGU, 2013]

12 BDS 지상부분의개형 national wide-area RSs - 1,200 regional RSs [Source: China Satellite Navigation Office, 2016]

13 BDS 의다양한보강모드비교 [Source: China Satellite Navigation Office, 2016]

14 고찰

15 기존의중앙집중형구조 Examples - GPS master station : satellite/receiver IFB - IGS : global ionospheric delay model, satellite receiver IFB - Space-based augmentation system Centralized Master Station Algorithm - huge-dimensional centralized filter - high-dimensional functional basis functions for ionospheric delay - no processing on tropospheric delay - Focuses on code measurement processing reports raw measurements No Differential Module satellite/receiver clock errors satellite/receiver inter-frequency bias orbit errors ionospheric delay no tropospheric delay No Standalone Module dedicated/selected reference stations no precise timing/positioning for each station pair

16 기존의분산형구조 Example - Trimble GPSNet TM Optional Fusion Module (Centralized Frame Filter) orbit errors satellite clock errors Master Fusion Module (Federated Geometry Filter) reports estimated satellite clock errors CORS reports raw measurements from boundary stations No Differential Module Standalone Module CORS satellite/receiver clock errors orbit errors tropospheric delay CORS CORS CORS CORS CORS X. Chen, U. Vollath, H. Landau, "Federated Filter Approach for GNSS Network Processing," Proceedings of IAIN World Congress 2006, Jeju

17 기존의 Inter-Station 처리개형 Example -VRS, FKP, MAC -Derives seudo-differential ionospheric error as dispersive error (DD method) - Other error terms are merged into non-dispersive error DD integer amibiguity resolution DD or pseudo-sd ionospheric error no differential timing no differential IFB Master CORS Auxiliary CORS 1 Auxiliary CORS 1 CORS

18 위성항법상대및절대변수사이의관계 DD ionospheric delay, tropospheric delay, and integer ambiguity SD ionospheric delay (master satellite) SD tropospheric delay (master satellite) SD integer ambiguity (master satellite) SD receiver inter-frequency bias SD ionospheric delay, tropospheric delay, integer ambiguity, and receiver inter-frequency bias references for absolute values statistics modeling Absolute ionospheric delay, tropospheric delay, receiver/satellite inter-frequency bias, timing and ephemeris information

19 변수사이의내부관계

20 요소기술

21 이기종수신기인터페이스및 GNSS 네트워크형성기술 기준국망정보입력 파일, 사용자의입력 IP, Port, ID, Password 기준국망스캔 NTRIP Server NTRIP Broadcaster TCP/IP CLNT TCP/IP SERV TCP/IP 1. SERV 2. CLNT TCP/IP CLNT Serial Stream NTRIP Client Ntrip 1. Source table 수신 2. Mount Point 3. 데이터수신 4. 데이터형태, 기준국위치, 측정치의종류, 전송률판별 기준국망개형설정 1. 연결개형설정 (ex. Delaunay triangle) 2. Master Station 설정 기타수신기망 / 사설기준국 1. 데이터수신 2. 데이터형태, 기준국위치, 측정치의종류, 전송률판별 NTRIP Client Receiver 기준국망접속및데이터수신 RINEX 파일저장 수신데이터처리 TCP/IP SERV 네트워크형성을위한단위구조 NTRIP Broadcaster 1. 비동기데이터처리 2. 동기데이터처리 3. 보정데이터생성 네트워크형성을위한접속 / 데이터처리순서도

22 전리층 / 대류권지연의절대값추정 다수의상시관측소로부터단일필터를활용하여절대값을실시간추정하기에는난점이있음 넓은영역의비정상적전리층지연분포를제한된차수의기저함수로모델링하 기에는난점이있음 Load Reference Station RINEX file Load IGS IONEX file Satellite DCB correction Multipath/Cycle-Slip Detection detected? NO YES Kalman Filter Partial Reset Ionospheric Pierce Point IPP Spatial Interpolation Kalman Filter Algorithm GPS Time Temporal Interpolation Plot results 전리층지연절대값추정순서도

23 다중위성군채널간편이 / 주파수간편이추정기법 항법신호의송 / 수신기내전달속도는 RF 회로, 채널별특성, 그리고주파수특성에따라변화하며미지정수결정에크게영향을미치는요인임 수신기 / 위성혼합주파수간편이, 수신기 / 위성혼합채널간편이, 그리고수직전리층지연을동시에분리추정하는방안의연구필요 단일수신기 GPS IFB 예시

24 다중 GNSS 보정정보생성및감시기술 타위성항법군의모니터링을위하여 GPS, GLONASS, Beidou, Galileo 등다수 GNSS 에대하여각위성항법군의측정치에대한보정정보생성및감시기능수행필요 각위성항법군별좌표계, 시간계, 항법메시지, 시간보정, 위성궤도, 각종보정계수등의차이점을분석및구현필요 응용서버 사용자 보정정보 다중 GNSS 보정측위개형

다중 GNSS 미지정수결정 타위성항법군의정밀한모니터링을위하여선결되어야하는기능 ICB(Inter-Channel Bias)/IFB(Inter-Frequency Bias)/ISB(Inter-System Bias) 등의고려 필요 GPS/GLONASS Measurements Ref. Rov.

25 다중 GNSS 미지정수결정 타위성항법군의정밀한모니터링을위하여선결되어야하는기능 ICB(Inter-Channel Bias)/IFB(Inter-Frequency Bias)/ISB(Inter-System Bias) 등의고려 필요 GPS/GLONASS Measurements Ref. Rov. DCB(Differential Code Bias)=Code IFB* RTK Procedure EKF Baseline, DCB, ICB, N AR (GPS only) Fixed N (G) Baseline Float N (R) Residual Based ICB Search Float N (G/R) ICB Yes AR (GPS/GLONASS) Fixed N (G/R) Yes Fixed/Float Solution No No Residual Based ICB Search Float N (R) ICB AR (GPS/GLONASS) Fixed N (G/R) ICB 를고려한미지정수결정전략

26 네트워크내전체미지정수수준화 상시기준국간기저선의길이에따라미지정수결정성능및정확도에영향을미침 대량의기저선으로구성된 GNSS 네트워크에서각기저선별로추정된보정치는각기다른기준에대한상대값에해당함 따라서, 미지정수값들을통일된기준으로맞추기위한미지정수수준화가 필요함 주기준국 Leveling 네트워크내미지정수수준화전략

27 SDR 인터페이스기능및기준국으로의활용 다양한위성항법군에대한항법신호수신가능 기저대역에서 jamming/interference 등에다양하게대처가능 하드웨어 GNSS 수신기보다경제성, 유연성및개방성등의이점이있음 Beidou GLONASS SBAS GPS Galileo G1/G2 L1/L5 L1/L2/L5 B1/B2/B3 SDR CORS SDR CORS E1/E5(a,b)/E6 SDR CORS SDR CORS SDR CORS SDR CORS SDR CORS SDR CORS SDR CORS SDR CORS SDR CORS SDR CORS SDR CORS SDR CORS SDR 기준국활용개형

28 temporal variation 이기종시공간측정치융합기법 시간영역에서주로활용되는 Kalman 필터링과공간영역에서주로활용되는 Krigging을결합하여상태변수영역에서의시공간융합연구를수행하 보다일반화된시공간영역에서의보정정보생성을위해시각동기화되지않은측정치들에대한시공간융합기법이필요함 t-1 t-2 t-3 spatial variation t-1 t-2 t-1 t-2 t-3 t-3

29 고장검출 / 분리및네트워크재형상기법 측정치영역과상태변수영역에서의위성과기준국의고장검출 / 분리기법연구필요 고장검출된기준국을제외하고마스터스테이션기능의중단없이자동적으로재형상 (re-configuration) 하는기능이필요함 재형상

30 무중단기준국추가 / 분리 실시간운영을끊김없이유지하면서다수의새로운기준국들을네트워크에추가 / 분리할수있는기능 기준국의추가 / 분리시에네트워크에서제공되는다양한정보제공의연속성보장을위하여필요함 추가기준국 추가 / 분리 분리기준국

31 구조연구

32 차분모듈을고려한분산화구조 Master Fusion Module Standalone Module CORS Differential Module CORS CORS CORS CORS CORS CORS

33 기본적인분산구조개형 Master Fusion Module (MFM) Differential Module (DM) Standalone Module (SM)

34 A DM (differential module) generates accurate estimates on differential receiver DCB (differential code bias), ionospheric delay, and tropospheric delay An SM (standalone module) generates coarse estimates on absolute DCB, ionospheric delay, tropospheric delay, and residual biases for each satellite An MFM (master fusion module) combines information from DMs and SMs to generate accurate estimates on absolute values

35 주요변수들사이의관계 Iono-Free Carrier Iono-Free Carrier Iono-Free Carrier Iono-Free Iono-Free Code Iono-Free Code Code Station N Station 2 Station 1 Geometry-Free Geometry-Free Geometry-Free Carrier Carrier Carrier Geometry-Free Geometry-Free Geometry-Free Code Code Code Tropo. Delay Combined SCE/RCE/OBE IF Cycle Ambiguity SDCB RDCB (isolated) Iono. Delay Combined SDCB/RDCB GF Cycle Ambiguity Fusion Module Tropo. Delay SCE RCE OBE IF C.A. Iono. Delay SDCB RDCB GF C.A.

36 개선방향 항목기존발전 GNSS 네트워크운용소프트웨어엔진 국외제품구매 / 변형활용 자체개발 측정치융합기법 공간영역 시공간영역 이기종수신기활용 활용않음 활용가능 보정파라미터생성 코드 코드 / 위상 고장검출, 분리, 네트워크재형상기능 불가능 가능 네트워크확장및분리의용이성 불편함 용이함 기존 발전

37 Fusion 모듈이이중화된분산구조개형 Master Fusion Module 2 (MFM 2) Master Fusion Module 1 (MFM 1) Differential Module (DM) Standalone Module (SM)

38 기능평가 : 전리층지연 /DCB 분리추정

39 성능평가 (1/6) # 실험개요 *GP m : group m (5 개의수신기로구성 ) **GP mn : group m + group (m+1) + group n (m n) 기준국위치

40 Vertical Ionospheric Delay [m] Vertical Ionospheric Delay [m] 성능평가 (2/6) 6 5 latitude: 40 longitude: 120 RMS difference: 0.53 m time (2 hours) 7 * red line with circle : IGS final product * other lines : proposed method RIM [TECU] time (2 hours) latitude: 35 longitude: 115 RMS difference: 0.87 m

성능평가 (3/6) L1 pseudorange measurement r c t t T 1 OF VID v j j j j j j 1, k k u, k k k k k 1, k Ionosphere-free measurement combination r j : geometric distance from receiver to satellite j c tu t :

41 성능평가 (3/6) L1 pseudorange measurement r c t t T 1 OF VID v j j j j j j 1, k k u, k k k k k 1, k Ionosphere-free measurement combination r j : geometric distance from receiver to satellite j c tu t : receiver and satellite clock error T j : tropospheric delay f f r c t t T 2 2 j 1 j 2 j j j IF u f1 f2 f1 f 2 j j j j IF, error IF r c tu t T Non-dispersive error correction r OF VID v j j j j j j j 1 IF, error IF 1 오직전리층지연만이위치오차의주요요인이되도록인위적으로실험환경설정

42 성능평가 (4/6) 수평위치오차 3 daej 기준국 RIM 생성에 참여하지 않음 오차요인을 전리층 지연으로 고정함 2 north [m] east [m] north [m] 3 north [m] north [m] (a) Correction by the IGS final product east [m] 1 2 (b) Correction by GP east [m] 1 2 (c) Correction by GP east [m] 1 (d) Correction by GP17

43 성능평가 (5/6) 수평 / 수직위치오차 (RMSE) IGS final product 활용대비수직 : 52 ~ 57 % 향상, 수평 : 16 ~ 48 % 향상

44 processing time [msec / epoch] 성능평가 (6/6) Processing Time [ms] 4.6 지역필터에서의매시점평균처리시간 reference station index Reference Stations Local Kalman Filter RIM (Kriging) Total 단일중앙집중형구조의경우 100 개의기준국활용시 1 초이상의시간이소요될것이라예상됨 - 네트워크지연은포함되지않음

45 TGD (Timing Group Delay) TGD 1 1 j j tsv, L1 P tsv, L2P SDCB

46 기능평가 : 상대전리층추정

47 성능평가 : Interpolated Dispersive/Non-Dispersive Error 비전파 CD (GPS) : 1, 9, 20, 28 비전파 CD (GLONASS) : 44, 45, 46, 56 전파 CD (GPS) : 1, 9, 20, 28 전파 CD (GLONASS) : 44, 45, 46, 56

Comparison of Relative Positioning Accuracy

60 (a) 단일기준국기반 RTK (a) 단일기준국기반 RTK North

28 (b) 상용 VRS 기반 RTK (b) 상용 VRS 기반 RTK North

48 Comparison of Relative Positioning Accuracy North East Down RMSE (cm) (a) 단일기준국기반 RTK (a) 단일기준국기반 RTK North East Down RMSE (cm) (b) 상용 VRS 기반 RTK (b) 상용 VRS 기반 RTK North East Down RMSE(cm) (c) 개발 VRS 기반 RTK (c) 개발 VRS 기반 RTK

DM DM DM 상대전리층지연추정치의활용용도 SM : Standalone Module DM : Differential Module

Ionospheric Map IPP : Ionospheric Pierce Point VID : Vertical

SMleveled estimates DMleveled estimates regional IPP and VID estimates

49 DM DM DM 상대전리층지연추정치의활용용도 SM : Standalone Module DM : Differential Module FM : Fusion Module PSC : Partial State Correction RIM : Regional Ionospheric Map IPP : Ionospheric Pierce Point VID : Vertical Ionospheric Delay IM : interface module FM local state estimates SMleveled estimates DMleveled estimates regional IPP and VID estimates RIM SM SM SM SM SM Fusion DM Fusion PSC PSC PSC PSC RIM IM SM PSC RIM differential integer ambiguities

50 수신기 / 네트워크인터페이스

51 소프트웨어패키지 GAFAS 의구성 GAFAS is the abbreviation for GNSS Algorithm For Accuracy and Safety

52 GAFAS 현황 작성언어 / 환경 C++ / Windows 활용가능한위성항법군의종류 GPS, Glonass, Galileo, BeiDou 수용가능한수신기의종류 Trimble, Novatel, Septentrio, U-blox 인터페이스의다양성 File, Serial TCP/IP : Sever, Client, P2P Ntrip : Broadcaster, Server, Client mode 메시지포맷의다양성 다수제조사들의고유포맷 RINEX 2.0, RINEX 3.0 RTCM 2.3, RTCM 3.0 동기가능한센서의종류 IMU, 영상센서, 고도계, OBD-II * 최근에추가된기능들

GAFAS 실행파일의다운로드 연구실홈페이지 (http://nisl.kau.

53 GAFAS 실행파일의다운로드 연구실홈페이지 ( 에서 GAFAS 링크를클릭하면실행파일과매뉴얼을다운로드할수있습니다 ~

54 시뮬레이션 : 기준국유입및소실에 대응하는재형상기능

55 Network Configuration Delaunay 삼각분할활용 기준국의유입및유출을고려 기선별데이터처리상태를기선의미지정수결정여부에따라나누어관리

56 결론

57 결론 위성항법지상부분은고장에대한대비를위하여점진적으로다중화하는추세임 (GPS 현대화 ) 중요도와보안성이다른서비스별로참여기준국을달리활용하는추세임 (QZSS, BDS) 보다향상된서비스를위해서는점진적으로기준국 (Monitoring Station) 의수를증가시키는추세임 (QZSS, BDS) 자국의위성항법시스템뿐아니라타위성항법시스템의성능을모니터링하고활용하는추세임 (QZSS MADOCA) 추후한국형위성항법시스템개발에있어서는적어도 1 개이상의서비스는타국에대한의존없이독자적으로개발할필요있음 다양한고장과유지 / 보수상황에위성항법지상부분이유연하게대응하고끊김없이서비스를제공하기위해서는무중단실시간고장검출 / 분리 / 재형상기능이고려되는것이바람직함

58 참고문헌 - 이형근, "GAFAS: 정확성과안전성을위한 GPS 알고리즘 ", 2004 항공전자심포지엄논문집, Nov. 11, 이형근, "GPS 측정치처리용소프트웨어모듈 GAFAS 의소개 ", 한국항행학회, Nov. 4, H.S. Kim, J.Y. Shim, H.K. Lee,"Designing a GPS Receiver Network with GNSS Algorithm for Accuracy and Safety," Paper #135, Proceedings of IGNSS 2007, 4-6 Dec., Sydney, Australia, H. K. Lee and C. Rizos, "Position-Domain Hatch Filter for Kinematic Differential GPS/GNSS", IEEE Transactions on Aerospace and Electronic Systems, Vol. 44, No. 1, pp , H.S. Kim, H.K. Lee,"Real-Time Implementation of L1 RTK System Based on Position-Domain Hatch Filter," Proceedings of European Navigation Conference, May 3-6, Naples, H.S. Kim and H.K. Lee,"Compensation of Time Aignment Error in Heterogeneous GPS Receivers," Proceedings of IAIN World Congress, Oct , Stockholm, H.S. Kim, H.K. Lee,"Real-Time Implementation of L1 RTK System Based on Position-Domain Hatch Filter," Proceedings of European Navigation Conference, May 3-6, Naples, 김희성, 이제영, 박제두, 최광호, 이영준, 최종준, 김민우, 이형근, " 국내 GPS/GNSS 상시관측소데이터의실시간통합활용방안연구 ", 제 17 차 GNSS 워크샾논문집, Nov. 4-5, 제주, 김희성, 이형근, " 차선별교통모니터링을위한위성항법수신기망설계및성능평가 ", 한국항행학회논문지, Vol 14, No. 2, pp , H.S. Kim, J.Y. Lee, and H.K. Lee,"A Differential Reference Station Algorithm for Modular Decentralized GPS/GNSS Master Station Architecture," Proceedings of International Symposium on GPS/GNSS, Oct , Taipei, 최광호, 이제영, 최종준, 김희성, 이형근, "GNSS 상시관측소기준국망을이용한실시간지역전리층감시기법 ", 제 18 차 GNSS 워크샾논문집, Nov. 3-4, 제주, H. S. Kim, J. Y. Lee, and H. K. Lee, "Estimation of Inter-Channel Bias and Ambiguity Resolution Strategy in GPS/GLONASS Combined RTK Positioning," Proceedings of IAIN World Congress, Oct. 1-3, Cairo, K. H. Choi, H. S. Kim, J. Y. Lee, J. H. Lim, and H. K. Lee, "Real-time Monitoring of Detailed Regional Ionospheric Activities by GPS CORS Networks," Proceedings of IAIN World Congress, Oct. 1-3, Cairo, H. S. Kim and H. K. Lee, "Elimination of Clock Jump Effects in Low-Quality Differential GPS Measurements," Journal of Electrical Engineering & Technology Vol. 7, No. 4, pp , K. H. Choi, J. Y. Lee, H. S. Kim, J. R. Kim, and H. K. Lee, "Simultaneous Estimation of Ionospheric Delays and Receiver Differential Code Bias by a Single GPS Station," Measurement Science and Technology, Vol. 23, No. 6, Article # , J. Y. Lee, H. S. Kim, and H. K. Lee, "Detection of Multiple Faults in Single Frequency Differential GPS Measurements," IET Radar, Sonar and Navigation, Vol. 6, No. 8, pp , 김희성, 이제영, 최광호, 임준후, 강성진, 이형근, " 분산형네트워크 RTK 시스템구현및성능평가 ", 한국위성항법시스템학회정기학술대회, 제주, Nov. 6-8, K. H. Choi, J. H. Lim, W. J. Yoo, and H. K. Lee, "Distributed Processing of GPS Receiver Network for Regional Ionosphere Map," Measurement Science and Technology, Vol. 29, No. 1, Article #015104, 2017

59 경청해주셔서감사합니다!

Ionospheric Disturbances in Earthquake re

Ionospheric Disturbances in Earthquake re 다중신호원 (GPS/GLONASS) 기반전리층지연, 주파수간편이, 채널간편이, 그리고미지정수의분리추정 2012 년 10 월 한국항공대학교항공전자및정보통신공학부 최광호, 김희성, 이제영, 임준후, 이형근 * 참고문헌 (references) [1] 이형근, "GNSS 수신기망개발동향 ", 제어자동화시스템공학회지, Vol. 12, No. 1, pp. 47-51,