1. GPSRO Data Processing and Science Applications at UCAR Bill Kuo UCAR COSMIC

2. Outlines Status of FORMOSAT-3/COSMIC Planning for FORMOSAT-7/COSMIC-2 Missions of Opportunities GPSRO data processing at UCAR GPSRO science applications Possible areas for collaboration

3. Successful COSMIC Profiles 4/21/06-12/12/10 Neutral Atmosphere ~ 2.5M Ionosphere EDPs ~ 2.6M

4. Current COSMIC Spacecraft/Payload Status FM1FM2FM3FM4FM5FM6 Space- craft Nominal- Lost 1 of 2 solar arrays - Average ~50 % duty cycle (Currently ~ 70%) - Frozen solar array drive - Average ~50% duty cycle - Lost contact Aug 1, 2010 Battery concern? Lost contact Sep 26, 2010 Returned Nov 10, 2010 - GOX Payload -POD-01 low SNR -- - OFF - Lost POD-00 POD-00,03 low SNR FORMOSAT-3/COSMIC sounding number went below 1000 in Nov 2010, and now a little over 1000 per day.

5. Continuation of GPSRO measurements FORMOSAT-3/COSMIC has a mission life of five years. Gradual degradation of the constellation is to be expected after 2011. It is essential to have the follow-on mission (F7/C2) to continue and enhance the GPSRO measurements. We should also look at the possibility of using other international research missions for operations

6. FORMOSAT-7/COSMIC 2 6 A Possible Design for FORMOSAT- 7/COSMIC-2

7. System Requirements GNSSRO Level 1 Requirements Documents (L1RD) status L1RD Completed and signed 5 May 2010 L1RD assessment underway Initial budget/partnerships for COSMIC-2 do not fully support all L1RD requirements C-2 was designed to be a replication of C-1 – except X2 satellites (12) All at 72 degrees 2 northern tracking stations with current latency (around 60 min average) L1RD requires 2 inclinations – 72 degrees and 24 degrees L1RD requires 45 min average latency Partnering with the AF for SSAEM (Space Situational Awareness Environmental Monitoring) sensors – 2 secondary payloads on 6 satellites AF purchase of rockets will close budget shortfall – allow us to meet all L1RD threshold requirements

8. FORMOSAT-7/COSMIC 2 Schedule First Launch in mid 2014, Second launch in mid 2016

9. F7/C2 Current Activity Mission Definition Review – successfully completed in August 2010 TriG Payload – SRR complete in August 2010 – PDR planned for November 2010 – Antenna design kicked off for COSMIC-2 – Procurement strategy in draft Air Force is proceeding with partnership – Payloads contracts work – Discussions with STP for the Minotaur 4 – received ‘11 funding – AF provided draft MOA under review at NOAA NSPO is moving forward quickly on spacecraft procurement – RFI released in May 2010 – 5 RFIs under review – Plans to release RFP for 12 spacecraft by January 2011 NOAA working ground planning – Discussions with KSAT (Kongsberg Satellite Services, Norway) on ground station options – Working with UCAR on proposal to “operationalize” CDAAC processing software to install at NSOF

10. GNSS RO Possible Missions of Opportunity (MOOS) (Excluding NASA Decadal Missions)

11. GNSS RO Possible Missions of Opportunity MissionLaunch- Duration GNSS RO Payload Orbit (alt/inc/ LT)# Occs Per day Operational/Real -Time F7/C22015JPL TriG (GPS,Galileo)800km/72,24°/->8,000Yes METOP-B2012GRAS (GPS)817km/98.7°/09:30LT~600Yes OceanSat-22009ROSA (GPS)720km/98.3°/12:00LT~500No KOMPSAT-52010IGOR+ (GPS)685km/98.5°/06:00LT~500No Megha-TropiquesTBDROSA (GPS)867km/20°/-~500No SAC-DTBDROSA (GPS)657km/98.5°/10:15LT~500No TanDEM-X20IGOR (GPS)514km/97.4°/18:00LT~500No PAZ2012IGOR+ (GPS)510km/97.4°/-~500No EQUARS2012IGOR (GPS)750km/20°/-~500No CNOFS2008BlackJack (GPS)853/405km/13°/-~250Best effort SAC-C2000BlackJack715km/98.5°/10:15LT~200Best effort

12. Missions of Opportunity SAC-C (Satélite de Aplicaciones Cientificas – C) Argentinian CONAE mission launched Nov 2000 715km altitude, 98° inclination, 10:15 LT JPL BlackJack, Open Loop, four single patch antenna Near real-time data provided by Germany’s GFZ and CONAE CDAAC providing 140-180 occultations per day to NOAA ~ 50-60% success from tracked profiles UCAR working with Tom Meehan and CONAE configure GPS receiver to track rising occultations all day (now only 10- 18 UTC) reduce negative impact of aging oscillator

13. Near Real-time SAC-C/COSMIC Global stats SAC-CCOSMIC

14. Missions of Opportunity TerraSAR-X, German mission, Launch Jun 2007 -BRE IGOR -GFZ providing NRT ~200 setting profiles to GTS (UCAR assisted GFZ in debugging problem) Tandem-X, German mission, Launch Jun 2010 -BRE IGOR -Identical orbit as TerraSAR-X, useful for scientific studies OCEANSAT-2, Indian mission, Launch Sept 2009 -ROSA receiver -Yaw-biased attitude, 35 degrees -Commissioning phase, no data available KOMPSAT-5, Korean mission, IGOR+, Launch 2010? -BRE IGOR+ PAZ, Spanish mission, IGOR+, Launch in Jan 2012 -IGOR+ -Tom Meehan says firmware must be modified to provide data useful for RO. This effort is not funded

15. CDAAC CDAAC NESDISNESDIS GTS NCEP ECMWF CWB UKMO Canada Met. JMA 1500-2000 WMO BUFR Files per day with Latency ~ 75-90min Getting COSMIC Results to Weather Centers JCSDA Meteo France COSMIC Operational Processing Science & Archive TACC AFWA Input Data - COSMIC data - GPS ground data - GPS NDM Bits - GFS Forecast - IGS/IGU ORB/CLK - Bernese Config files Research Community SFTP UCAR/Unidata’s LDM WGET RTSs: Alaska Norway Antarctica/McMurdo CDAAC reliability estimated > 99.5%, Latency ~ 75-90 min

16. Main CDAAC Functions RO Payload Operation – Configuration control (firmware and tracking configuration) – Scientific/technical guidance for commanding, operation – Near real-time monitoring, trouble-shooting, and Q/C data analysis Data Processing and Analysis – Level0 unformatting and QC – GPS ground processing (ZTD, site estimation, clock estimation) – LEO POD, and atmospheric excess phase – Absolute TEC generation – Inversions (neutral atmosphere and ionosphere) – Retrievals (1DVAR) – NWP and correlative data handling – Product QC and analysis

17. CDAAC Functions (cont) System Operation and Monitoring -H/W, O/S and NFS filesystem -System fail-overs -CDAAC operations Input data stream monitoring –RTS downlink –GPS Bit-grabber operation and monitoring –GPS ground data (IGS, NRCan, EUMETSAT, COSMIC sites) –IGS and IGU orbits, clocks and EOP (Earth Orientation Parameter) –Bernese configuration –NCEP GFS, ECMWF, radiosonde, ionosonde Data Management, Dissemination, and Archival Support Data Users

18. Best Effort Monitoring Monitor the system regularly throughout the day M- F 8am-8pm CDAAC Ops team monitors the system 3 times per day on weekends and holidays Available by email and cell phone CDAAC reliability estimated > 99.5%

19. COSMIC/CDAAC Status CDAAC 3.0 released late November 2010 Post-Processing continues … -Pushing COSMIC to public website -Metop/GRAS 2010 on website COSMIC recently producing ~1,000 occultations/day CNOFS producing ~125 occs/day -Interpolating 1Hz L2 to 50 Hz -Working with Paul Straus to modify CORRISS firmware SAC-C producing 125-150 occs/day -Working with CONAE/JPL to update firmware -Finalizing agreement with GFZ to provide SAC-C support for 2011

20. F7/C2 Data Processing Center Requirements Reliable and low latency input data streams (GNSS ground network, LEO data from RTSs,..) Primary and Backup Data Processing Center (DPC) Development system (GNSS capable) Staging system to test processing changes Communication access between systems (DPCs, SOCC, RTSs) Monitoring of near real-time operations Maintenance and on call technical support Operator Training Science payload processing Post-Processing and archiving

21. NOAA Operational DPC Requirements Primary DPC at NOAA/NSOF (NOAA Satellite Operations Facility) – Single/Dual string (operational call) – 24/7 monitoring – Virtualization of processing S/W – SW Staging/testing string Backup DPC at off-site location – Single/Dual string (operational call) – Hot/Cold Backup (operational call) – Return to Service (operational call) – < 24/7 monitoring (operational call) – Tested yearly, documentation

22. Post-Processing and Archive Plan Post-processing requires use of up-to-date software and algorithms Technical and scientific expertise are required to monitor processing and validate data analyses UCAR plans to post-process F-7/C-2 data Archive via NOAA CLASS system – Level0 and higher level products – Must find host at Data Center (NGDC, NCDC,..). Process started UCAR will archive real-time and post-processed data on NCAR HPSS (High Performance Storage System) Taiwan DPC archive

23. CDAAC System changes Better system for managing code for production/research Restructure portions of software Add more test suites Clean up unused code Improved QC, bad flags, error estimates Multi-GNSS capability, new observables! Low latency processing Better systems management Need to develop F-7/C-2 Level0-Level1 processing modules Improved monitoring scripts Improved documentation

24. Neutral Atmospheric Inversions Restructure ROAM (Radio Occultation Atmospheric Measurements) Add GNSS capability, new observables Improve wave optics processing – looking for better filtering approaches – looking for alternative methods (like recently introduced WDF) Improve bending angle optimization -testing methods with reduced weight of climatology -validation by independent data sources in the stratosphere Improve 1DVAR retrieval code and documentation Perform additional validation studies (e.g. integrate ROPP package, RO-Trends+)  Requires investigation and understanding the sources of the differences

25. 1) Phase Connection 2) Bending Angle Generation (WO,GO) 3) Bending Angle Correction, Connection 4) Bending Angle Optimization, Inversion atmPhs conPhs benPrf bcnPrf atmPrf 1) Mission-dependent; 2-4) Mission-independent. 1) Input positions, velocities, raw phase and amplitude, clim. model. Processing removal of NDM, connection of the phase, down-sampling to one rate. Output positions, velocities, connected phase, amplitude, HSL, lat, lon, height of TP. 2) Input output from 1 Processing retrieval of WO (Phase Matching and FSI or CT2) and GO bending angles for L1, L2, (L5) Output GO and WO bending angles for L1,L2,(L5) 3) Input output from 2 Processing ionospheric correction (incl. additional smoothing of L4), connection of GO and WO bending angles. Output ionosphere free connected bending angles 4) Input output from 3, clim. model, atm. model. Processing optimization of bending angles, inversion of N,T,P. Output N,T,P.

26. Absolute TEC uncertainty under investigation -DCB estimation, Code/phase leveling uncertainty Electron Density Profiles -Improving EDPs (Electron Density Profiles) by using information on horizontal gradients with DA Improve scintillation products Add GNSS capability, new observables Perform additional validation studies -With Paul Straus of Aerospace, JPL Ionospheric Processing

27. Data impactData processing R&D Center Operation DPC NWP Operation COSMIC NCAR CDAAC R&D Backup Multiple missions NSOF/NOAA DPC NCEP TTFRI GPSARC CWB GPSARC R&D Backup CWB/NSPO DPC (TACC) CWB M.I.C. Parallel efforts between U.S. and Taiwan for F7/C2

28. Possible Collaboration between U.S. and Taiwan GPSRO data processing: – GPSRO data processing research, inversion, and algorithm improvement – Operational GPSRO processing GPSRO Science Applications: – Use of GPSRO data in operational NWP – Systematic evaluation of the impact of F3/C and F7/C2 data on typhoon and flood prediction – Ionospheric research and space weather – Climate applications, trend detection, post-processing

29. Data Assimilation Retrieval of Electron Density Profiles from Radio Occultation Measurements Yue, X., W. S. Schreiner, Y.-C. Lin, C. Rocken, Y.-H. Kuo, and B. Zhao, 2010: Data Assimilation Retrieval of Electron Density Profiles from Radio Occultation Measurements. J. Geophys. Res – Space Physics, 2010JA015980, (under review). Geomagnetic latitude and altitude variations of electron density during noon time (LT=13) Comparison of standard COSMIC Abel retrieval and data assimilation retrieval with Ionosonde data Simulation of retrieval errors for standard COSMIC Abel retrievals and data assimilation retrievals Truth Abel DA Abel Error DA Error Large Errors

30. Definition At sea level, difference between Z and z is zero because – Same geopotential height at sea level (geoid, g is same at reference height 0) Biases between z and Z depending on latitude and height – Due to difference of g and g 0  : geopotential [m 2 s -2 ] g : acceleration due to gravity [m s -2 ] Note: it depends on  and z  : latitude [deg.] z: geometric height [m] (CDDAC COSMIC RO) Definition of geopotential Geopotential height Z: geopotential height [m] (NWP, WRF, Meteorology) g 0 : standard gravity at mean sea level [m s -2 ] Note: it doesn’t depend on  and z Definition: the acceleration of a body in free fall at sea level at a geodetic latitude of about 45.5° Textbook of meteorology approximate that g doesn’t change with height and latitude, and then Z is almost close to z, but we cannot use the approximation in RO world. Plot in next slide:

31. In z (geometric height) –Z (geopotential height) plot above, positive value in equator shows g in equator is smaller than g 0. Negative value near pole in lower atmosphere is because g in pole is larger than g 0, but positive value in higher atmosphere (15km~) is, again, because g in higher altitude is smaller than g 0 Geoid height, 0m Real Earth (geodesy) Ideal sphere Earth In meteorology Center of mass

32. O-B Statistics in Original and Modified WRFVAR Positive biases in original WRFVAR are disappeared in modified WRFVAR Original Modified

33. 33 GPSv_NCEP ： operational with GPSRO GPSh_NCEP ： height-correction with GPSRO NOGPSv_NCEP ： without GPSRO H 00h 12h

34. 34 H 24h 48h 72h H-correction is comparable with NO GPSRO. For forecast, H-correction has slightly smaller RMS than NO GPSRO at higher levels. H-correction has smaller bias at model top.