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GPSRO Data Processing and Science Applications at UCAR. Bill Kuo UCAR COSMIC. 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.
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GPSRO Data Processing and Science Applications at UCAR Bill Kuo UCAR COSMIC
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
Successful COSMIC Profiles 4/21/06-12/12/10 Neutral Atmosphere ~ 2.5M Ionosphere EDPs ~ 2.6M
Current COSMIC Spacecraft/Payload Status FORMOSAT-3/COSMIC sounding number went below 1000 in Nov 2010, and now a little over 1000 per day.
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
FORMOSAT-7/COSMIC 2 A Possible Design for FORMOSAT-7/COSMIC-2
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
FORMOSAT-7/COSMIC 2 Schedule First Launch in mid 2014, Second launch in mid 2016
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
GNSS RO Possible Missions of Opportunity (MOOS) (Excluding NASA Decadal Missions)
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
Near Real-time SAC-C/COSMIC Global stats SAC-C COSMIC
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
Getting COSMIC Results to Weather Centers COSMIC Operational Processing TACC JCSDA NCEP NESDIS RTSs: Alaska Norway Antarctica/McMurdo UCAR/Unidata’s LDM CDAAC ECMWF Research Community WGET CWB GTS 1500-2000 WMO BUFR Files per day with Latency ~ 75-90min • Input Data • COSMIC data • GPS ground data • GPS NDM Bits • GFS Forecast • IGS/IGU ORB/CLK • Bernese Config files UKMO JMA AFWA SFTP Canada Met. Meteo France Science & Archive CDAAC reliability estimated > 99.5%, Latency ~ 75-90 min
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
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
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%
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
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
NOAA Operational DPCRequirements • 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
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
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
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 ROPPpackage,RO-Trends+) • Requires investigation and understanding the sources of the differences
atmPhs 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. 1) Phase Connection conPhs 2) Bending Angle Generation (WO,GO) benPrf 3) Bending Angle Correction, Connection bcnPrf 4) Bending Angle Optimization, Inversion atmPrf
Ionospheric Processing • 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
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
Data Assimilation Retrieval of Electron Density Profiles from Radio Occultation Measurements 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 Large Errors Abel Error DA Error 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 andaltitude variations of electron densityduring noon time (LT=13)
Definition Definition of geopotential F: geopotential [m2 s-2] g: acceleration due to gravity [m s-2] Note: it depends on f and z f: latitude [deg.] z: geometric height [m] (CDDAC COSMIC RO) • 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 g0 Geopotential height Z: geopotential height [m] (NWP, WRF, Meteorology) g0: standard gravity at mean sea level [m s-2] Note: it doesn’t depend on f 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:
Ideal sphere Earth In meteorology Center of mass Real Earth (geodesy) Geoid height, 0m • In z (geometric height) –Z (geopotential height) plot above, positive value in equator shows g in equator is smaller than g0. • Negative value near pole in lower atmosphere is because g in pole is larger than g0, but positive value in higher atmosphere (15km~) is, again, because g in higher altitude is smaller than g0
O-B Statistics in Original and Modified WRFVAR Positive biases in original WRFVAR are disappeared in modified WRFVAR Original Modified
GPSv_NCEP:operational with GPSRO GPSh_NCEP:height-correction with GPSRONOGPSv_NCEP:without GPSRO H 00h 12h
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.