Taiwan Radio Occultation Process System (TROPS) Cheng-Yung Huang, Wen-Hao Yeh, Kun-Lin Chen National Space Organization, National Applied Research Laboratories Shu-Ya Chen, Jing-Mei Wu, Hsiu-Wen Li, Kuo-Hsin Tseng, Yi-Shan Li GPS Science and Application Research Center, National Central University Hsu-Hui Ho, Jyun-Ying Huang, Taiwan Analysis Center for COSMIC, Central Weather Bureau Tzu-Pang Tseng Geoscience Australia (GA)
The Data Flow chart of Taiwan Radio Occultation Process System (TROPS) National Space Organization (NSPO), National Applied Research Laboratories, Taiwan Taiwan Analysis Center for COSMIC (TACC), Central Weather Bureau, Taiwan GPS Science and Application Research Center (GPSARC), National Central University, Taiwan Global Data sources 10.0 Fetch raw data LEO raw data 1.0 Process management 2.0 Ground data process 3.0 P3 GPS orbit process 4.0 P4 LEO data process Intermediate data 5.0 P5 Ionospheric occ. process High-level data 6.0 P6 Atmospheric occ. process Data Base 12.0 AP system management 11.0 Monitor System 14.0 environment management 13.0 High level product generation CWB Forecast & Model Taiwan Science Team Data/Product Archive Global Users 8.0 Data delivery & Archive 9.0 Web/FTP service raw data Intermediate data High-level data Data Base
Ne w d a ta typ e fo r lo w ra te LEO o rb it c o m p u ta tio n in c o m p re sse d RINEX fo rm a t "p o d C rx" is a va ila b le a t b o th TAC C a n d C DAAC. Th e o rig in a l d a ta in BINEX fo rm a t "p o d G p s" a n d RINEX fo rm a t "p o d O b s" w ill b e p h a se d o u t. < An n o u n c e d a te : Fe b. 4, 2012> Ne w FTP se rve r fo r FO RMO SAT-3/ C O SMIC p ro d u c ts is a va ila b le a t TAC C. Th e m a c h in e ta c c.c w b.g o v.tw n o w p ro vid e s th e FTP se rvic e fo r FO RMO SAT-3 p o st-p ro c e sse d a n d re a l tim e d a ta a c c e ss. Use rs c a n u se th e c u rre n t u se r id a n d p a ssw o rd w ith th is se rvic e. Da ta a c c e ss via h ttp fro m TAC C w e b site still re m a in s fo r n o w. < An n o u n c e d a te : Ap r 15, 2010> Ne w C O SMIC a b so lu te TEC a rc file s (p o d TEC ) a re a va ila b le fo r d a ys 2008.001-2009.181. Du e to a b u g in th e c o d e, m a n y a rc s h a d p re vio u sly n o t b e e n g e n e ra te d. Th e re is n o c h a n g e in th e d a ta q u a lity, b u t o ve r tw ic e a s m a n y a rc s a re n o w a va ila b le. MOST Recent FORMOSAT 3/COSMIC Satellite Locations Sta rtin g O c to b e r 12, 2009 00:00UTC, th e TAC C n e a r re a l-tim e d a ta p ro d u c ts w ill in c lu dindependent e th e c h a n g e s e xp la in systems: e d in C O SMIC sta tu s u p d a te s fro m Ap ril 16, 2009 a n d Ma y 12, 2009. In a d d itio n, fu tu re C DAAC p o st-p ro c e ssin g re su lts w ill in c lu d e th e se c h a n g e s sta rtin g th e m o n th o f Ap ril 2009. Th e se re su lts w ill b e d e sig n a te d w ith a n e w ve rsio n n u m b e r (2009.2650). We a re p la n n in g to im p le m e n t th e c h a n g e s e xp la in e d in C O SMIC sta tu s u p d a te s fro m Ap r. 16 a n d Ma y 12 in o u r re a l tim e p ro c e ssin g so o n. An a d d itio n a l a n n o u n c e m e n t w ill b e p o ste d p rio r to th e tra n sitio n d a te. Th e BUFR file s fo r De c. 2008, Ja n.-fe b. 2009 o b ta in e d b y p ro c e ssin g w ith th e im p le m e n te d c h a n g e s a re a va ila b le fro m th e BUFR te st d a ta We b a re a To ta l So la r Ec lip se o f 2009 J u ly 22 2009/ 9/ 3 ~ 9/ 4 O SSE WO RKSHO P fo r th e FO RMO SAT-3/ C O SMIC Fo llo w -o n Missio n. Th e sta tistic o f FO RMO SAT-3/ C O SMIC d a ta u se rs C O SMIC Po stpro c e ssin g h ig h le ve l p ro d u c ts a re a va ila b le o n TAC C We b site. Taiwan Analysis Center for COSMIC (TACC) will process RO data by two TROPS (Taiwan RO Process System ) & CDAAC (COSMIC Data Analysis and Archive Center) TAC C p la n s to sw itc h to p ro c e ssin g w ith ve rsio n 2.0 so ftw a re o n O c to b e r 16, 2007, w h ic h sh o u ld re su lt in a slig h tly im p ro ve d su c c e ss ra te o f p ro file s th a t p a ss o u r q u a lity c o n tro l. We a n tic ip a te a n im p ro ve m e n t o f ~ 5%. Ne w flig h t so ftw a re w h ic h a lso sh o u ld in c re a se th e n u m b e r o f o c c u lta tio n s th a t w e tra c k is p re se n tly u n d e rg o in g te stin g a t JPL. Space Weather Atmospheric Weather c lu d e th e c h a n g e s e xp la in e d in C O SMIC sta tu s u p d a te s fro m Ap ril 16, 2009 a n d Ma y 12, 2009. In a d d itio n, fu tu re C DAAC p o st-p ro c e ssin g re su lts w ill in c lu d e th e se c h a n g e s sta rtin g th e m o n th o f Ap ril 2009. Th e se re su lts w ill b e d e sig n a te d w ith a n e w ve rsio n n u m b e r (2009.2650). We a re p la n n in g to im p le m e n t th e c h a n g e s e xp la in e d in C O SMIC sta tu s u p d a te s fro m Ap r. 16 a n d Ma y 12 in o u r re a l tim e p ro c e ssin g so o n. An a d d itio n a l a n n o u n c e m e n t w ill b e p o ste d p rio r to th e tra n sitio n d a te. Th e BUFR file s fo r De c. 2008, J a n.-fe b. 2009 o b ta in e d b y p ro c e ssin g w ith th e im p le m e n te d c h a n g e s a re a va ila b le fro m th e BUFR te st d a ta We b a re a To ta l So la r Ec lip se o f 2009 Ju ly 22 2009/ 9/ 3 ~ 9/ 4 O SSE WO RKSHO P fo r th e FO RMO SAT-3/ C O SMIC Fo llo w -o n Missio n. Th e sta tistic o f FO RMO SAT-3/ C O SMIC d a ta u se rs http://tacc.cwb.gov.tw/en/index.htm 1/2
GNSS CLOCK & POD (Tzu-Pang Tseng) Reduced-dynamic technique Bernese Software 5.2 60-80 Ground GPS Sites Update every 5 mins for FS-7/C-2
Flowchart of data processing GNSS clock NTRIP source (Global ground stations) Code data smoothing Outlier detection GNSS fiducial data Code data smoothing Outlier detection Update initial clock Update initial clock NTRIP casters IFB estimation Phase data cleaning Outlier detection Phase data cleaning Outlier detection Caster from Taiwan data processing center Station coordinates and ZTDs estimation using phase and the smoothed code Outlier detection Station coordinates and ZTDs estimation using phase and the smoothed code Outlier detection GPS clock determination GLONASS clock determination
GPS Clock Rate Requirement (0.5) TROPS (0.1339)
GLONASS Clock Rate Requirement (0.6) TROPS (0.2724)
Poor Clock Solutions
Fiducial streaming data Monitoring Real time station status distribution Real time station status list
Clock Rate comparison exception of PRN115 and PRN123 Only Block IIF type
Clock-Induced errors in the BA retrieval 828 RO events on DOY 123 in 2017 IGU-IGS:Ultra-rapid Final orbits GLN_1/GLN_2: IGS clock error * 2/3
TROPS IONOSPHERE (Wen-Hao Yeh) TEC inversion to retrieve Electron Density Cycle Slip detection for sharper electron density region. Multipath and leodcb correction for POD TEC
Ionosphere Electron Density Profile POD TEC profile The black profiles are the TEC profiles calculated by code. The blue points are the data calculated by the multipath correct procedure. And the red profiles are the final product of POD TEC algorithm."
TROPS IONOSPHERE TROPS vs. CDAAC NmF2 & HmF2 14
Retrieve rate of ionprf & podtec ionprf podtec
Worst Cases Analysis
TROPS ATMOSPHERE (Cheng-Yung Huang, Shu-Ya Chen) 1. Space Phase matching Method to retrieve Bending Angle 2. Correct Open-Loop with/without gpsbit data 3. Use NRLMSISE model for High Altitude Profiles currently, will replaced by ecmfct in future.
Measurement Uncertainty α N T GPH
VERIFICATION AGAINST OTHER DATA (ONE MONTH PERIOD) 1. Metop (DPC: ROPP) 2018.027~056 (2018/01/26~2018/02/25) 2. Radiosonde 2016.330~365 (2016/12/01~2016/12/30)
atmprf (FORMOSAT3-Metop) α N T TACC-ROPP TROPS-ROPP Data: ± 2h & ± 1 o lat,lon
wetprf (FORMOSAT3-Metop) T TACC- ROPP TROPS -ROPP q
SENSITIVITY ANALYSIS OF TROPS PRODUCT TO SATELLITE CLOCK ERROR Normal CASE1 CASE2 CASE3 leoclk 1.2 * leoclk leoclk ± RMS(leoClk) 10 * leoclk Data Period: Winter : 2016.010-2016.039 Summer : 2016.210-2016.239
Retrieval Rate (winter) Normal/Case1/Case2 Normal/Case1/Case3 atmphs atmphs atmprf atmprf
α Normal VS Case1 Normal VS Case2 Normal VS Case3 winter N T
α Normal VS Case1 Normal VS Case2 Normal VS Case3 summer N T
TDPC Neutral Atmosphere Verification and Validation Plan TGRS Checkout POD Performance Collocated Soundings Comparison Radiosonde Comparison Dropsonde Experiments Impact Assessment Global GSI Excess Phase FS-3/C & other RO Measurement Comparison TROPS NRT POD Verification TROPS Profiles Quality (BA/N/T/GPH) Impact Assessment Regional GSI Pseudorange & SNR Assessments RF Beacon & Beamforming ON/OFF Comparison TDPC GNSS Clock Impact Assessment Weather Forecasting Impact Assessment Typhoon Trace
Taiwan Radio Occultation Process System (TROPS) The Products of TROPS will be released after Verification and Validation, the date is expected to be L+210 days. Two documents (TACC web) will be released around L+210 days and L+2 years. Tseng Tzu Pang, Shu Ya Chen1, Kun Lin Chen, Cheng Yung Huang4, Wen Hao Yeh, Determination of near real-time GNSS satellite clocks for the FORMOSAT-7/COSMIC-2 satellite mission, GPS Solutions (2018) 22:47