COSMIC_spwx_report_rocken

Document Sample
COSMIC_spwx_report_rocken Powered By Docstoc
					    COSMIC: Constellation Observing
   System for Meteorology, Ionosphere
              and Climate
        Status and Results with Emphasis on the
                      Ionosphere
             Christian Rocken, Stig Syndergaard, Zhen Zeng
                       UCAR COSMIC Project


FORMOSAT-3
Outline
   COSMIC Introduction
   Results
    – Some neutral Atmosphere Results
    – Ionosphere
       »   GPS TEC Arcs
       »   GPS Electron Density Profiles
       »   Scintillation
       »   Validation / Comparison to Models
       »   TIP
       »   TBB
    – Latency and Data Distribution
   Summary
COSMIC (Constellation Observing System for
Meteorology, Ionosphere and Climate)
 6 Satellites launched
  01:40 UTC 15 April 2006
 Three instruments:
  GPS receiver, TIP, Tri-band beacon
 Weather + Space Weather data
 Global observations of:
  Pressure, Temperature, Humidity
  Refractivity
  Ionospheric Electron Density
  Ionospheric Scintillation
 Demonstrate quasi-operational GPS limb sounding with global
  coverage in near-real time
 Climate Monitoring
                    Tangent point


 vGPS                                                                         The LEO tracks the GPS phase
                                   F
                                     Qu i k Ti me ™ a d a
                                         c
                                          W) c
                               TIF (L Z d e o m p s s o
                                                        n
                                                         re     r
                                                                       LEO    while the signal is occulted to
                                                                              determine the Doppler
                                       e                    i
                           a re n e e d d to s e e th i s p c tu re.




                                                                       vleo




The velocity of GPS relative to
LEO must be estimated to ~0.2
mm/sec (velocity of GPS is ~3
km/sec and velocity of LEO is
~7 km/sec) to determine
precise temperature profiles
                    Tangent point


 vGPS
                                   F
                                     Qu i k Ti me ™ a d a
                                         c
                                          W) c
                               TIF (L Z d e o m p s s o
                                                        n
                                                         re     r
                                                                       LEO    The LEO tracks the GPS phase
                                                                              while the signal is occulted to
                                       e                    i
                           a re n e e d d to s e e th i s p c tu re.




                                                                       vleo   determine the Doppler




The velocity of GPS relative to
LEO must be estimated to ~0.2
mm/sec (20 ppb) to determine
precise temperature profiles
                 COSMIC Soundings in 1 Day




                                             COSMIC
                                             Radiosondes




Sec 3, Page 10
 Atmospheric refractive index n  c / v where c is the light velocity
 in a vacuum and v is the light velocity in the atmosphere

 Refractivity    N  10 6 (n  1)
              P           5 P            6 ne
     N  77 .6  3.73  10 2  40 .3  10 2
                              w
              T             T              f
                (1)             (2)                 (3)
• Hydrostatic dry (1) and wet (2) terms dominate below 70 km

• Wet term (2) becomes important in the troposphere and can
  constitute up to 30% of refractivity at the surface in the tropics

• In the presence of water vapor, external information information is
needed to obtain temperature and water vapor

• Liquid water and aerosols are generally ignored

• Ionospheric term (3) dominates above 70 km
6 Micro Satellites - USAF Minotaur
Rocket Integration
        Launch on April 14, 2006, Vandenberg AFB, CA



                                                            • All six satellites stacked and
                                                            launched on a Minotaur rocket

                                                            • Initial orbit altitude ~500 km;
                                                            inclination ~72°

                                                            • Will be maneuvered into six
                                                            different orbital planes for optimal
                                                            global coverage (at ~800 km
                                                            altitude)

                                                            • Satellites are in good health
                                                            and providing data-up to 2200
                                                            soundings per day to NOAA
COSMIC launch picture provided by Orbital Sciences Corporation
COSMIC Current Constellation
 COSMIC - Final Deployment

•6 Planes
•71 Degrees
inclination
•800 Km
•2500 Soundings
per day
•Latency 50-140
minutes from
observation to
NOAA
Some Neutral Atmosphere Results
                               00:07 UTC 23 April 2006,
                               eight days after launch



Vertical profiles of “dry”
temperature (black and red
lines) from two independent
receivers on separate
COSMIC satellites (FM-1
and FM-4) at 00:07 UTC
April 23, 2006, eight days
after launch. The satellites
were about 5 seconds apart,
which corresponds to a
distance separation at the
tangent point of about 1.5
km. The latitude and
longitude of the soundings
are 20.4°S and 95.4°W.
Comparison of Pairs of COSMIC soundings
with GFS analysis
Using COSMIC for Hurricane Ernesto Prediction

     With COSMIC             Without COSMIC




                            Results from Hui Liu, NCAR
Using COSMIC for Hurricane Ernesto Prediction

     With COSMIC               GOES Image




                          GOES Image from Tim Schmitt, SSEC
Southern Hemisphere Forecast Improvements from COSMIC Data




    Sean Healey, ECMWF
Northern Hemisphere Forecast Improvements from COSMIC Data




  Sean Healey, ECMWF
Space Weather
       QuickTime™ an d a
   TIFF (LZW) decomp resso r
are need ed to see this picture.
   GPS Antennas on COSMIC Satellites
        2 Antennas for orbits, TEC_pod (1-sec), EDP




                     COSMIC s/c                   Vleo




High-gain occultation antennas
for atmospheric profiling        Nadir
(50 Hz)
       QuickTime™ an d a
   TIFF (LZW) decomp resso r
are need ed to see this picture.
Total electron content data (podTEC)
   COSMIC generates 2500 - 3000 TEC arcs per day
   Sampling rate is 1 -sec




                                QuickTime™ and a
                            TIFF (LZW) decompressor
                         are neede d to see this picture.
            Absolute TEC processing
   Correct Pseudorange for local multipath

   Fix cycle slips and outliers in carrier phase data

   Phase-to-pseudorange leveling

   Differential code bias correction
       Satellite Multipath and Solar Panel Orientation




P1 Multipath                                   P2 Multipath
Pseudorange multipath calibration




                    QuickTime™ and a
                TIFF (LZW) decomp resso r
             are neede d to see this picture.
Phase-to pseudorange leveling statistics



                        QuickTime™ and a
                    TIFF (LZW) decomp resso r
                 are neede d to see this picture.
  COSMIC DCBs for ~ 1 year




Quality of absolute TEC from COSMIC ~2 TECU
Observed TEC Rays in 12-hour period
… observed in Local time
Latency of COSMIC podTec data
       QuickTime™ an d a
   TIFF (LZW) decomp resso r
are need ed to see this picture.
Profile retrieval method




              TEC = solid - dashed            [Schreiner et al., 1999]



                                   
                                       p top     rN(r)
             TEC( p) = 2                                     dr
                                       p         r 2  p2
        Inverted via onion-peeling approach to obtain electron density N(r)
        Assumption of spherical symmetry



First collocated ionospheric profiles
                             From presentation by Stig Syndergaard,
                             UCAR/COSMIC
Comparisons with ISR data
[Lei et al., submitted to JGR 2007]
        Comparison of Ne(h) between COSMIC (red), Ionosondes
             (green)and TIEGCM (black) on Aug. 17 - 21nd



COSMIC agree well
with ionosonde obs,
especially the HmF2;
Vertical structures
from COSMIC
coincide well with
TIEGCM in the mid-
lat, but not in the
tropics.
TIEGCM shows a bit
higher HmF2
compared with obs.
                                                                                           From presentation by Ludger Scherliess,
                                                                                           Utah State University

Comparisons during quiet and disturbed Conditions

                                                                      COSMIC #2 GAIM


                                                                                                                    Quiet




                                                                      COSMIC #2 GAIM


                                                                                                                    Storm




                                          Globa l Assimilat ion of Ionospheric Measurements
                                             Ut ah St at e Universi t y, ( 435 )7 97 -2 962 , schunk@cc.usu .edu;
                                          Universi t ies of Colorado ( Boulder), Texas ( Dallas), and Washingt on
    “ Bringing t he piece s to get her”
                                      From presentation by Zhen Zeng, NCAR/HAO

Comparison of NmF2 and HmF2 between COSMIC
      and GAIM during Apr. 21-28, 2006




  Good agreement of NmF2 between COSMIC and GAIM;
  Higher peak heights from GAIM than those from COSMIC
      QuickTime™ an d a
         decompressor
are need ed to see this picture.
Using GAIM to correct for gradients
                          From presentation by Stig Syndergaard,
                          UCAR/COSMIC




                             Courtesy of Zhen Zeng
       QuickTime™ an d a
   TIFF (LZW) decomp resso r
are need ed to see this picture.
              Scintillation Sensing with COSMIC
No scintillation                      Scintillation
S4=0.005                              S4=0.113




                                                      Where is the source
                                                      Region of the scintillation?



                   GPS/MET SNR data
   Formosat-3/COSMIC
Observations of Scintillations
                         From presentation by Chin S. Lin, AFRL



                  RED = COSMIC sat
                  BLUE = GPS sat
Observed TEC Rays in 12-hour period
       QuickTime™ an d a
   TIFF (LZW) decomp resso r
are need ed to see this picture.
TIP 135.6-nm passes 14 Sep 2006
FM1 FM3 FM6
0-24 UT (2100 LT)                 From presentation by Clayton Coker, NRL
Chung-Li COSMIC TBB/CERTO
                             From presentation by
   TEC and Elevation Angle   Paul A. Bernhardt, NRL
               Getting COSMIC Results to Weather Centers
          Neutral Atmosphere Operational Processing

                 TACC                                JCSDA
                                                                    NCEP
    I
    n                                        N                     ECMWF
                   C
    p                                        E
    u              D                                                CWB
    t                                        S     GTS
                   A
                         BUFR Files          D                     UKMO
    D              A
    a
                         WMO standard
                         1 file / sounding
                                             I
                   C                                                JMA
    t                                        S
    a                                                           Canada Met.
            Science & Archive                        NRL

Data available to weather centers within < 180 minutes of on-orbit collection
                        Summary
   COSMIC generates large amount of high quality space
    weather data

   Data available for real-time (significant amount of data
    with less than 60 min latency) and for post-processing

   Data are used for model comparison /improvement

   Global scintillation data will be available within months
A COSMIC Education Module

                                   A joint effort by COMET
                                   and COSMIC.


                                   It covers:
                                   - Basics of GPS radio
                                   occultation science
                                   - Applications to weather,
                                   climate, and ionosphere
                                   - COSMIC Mission
                                   description




      http://www.meted.ucar.edu/COSMIC/
                           COSMIC Data Access



http://www.cosmic.ucar.edu

* Select the 'Sign Up ' link under
COSMIC

•Accept data use agreement

* Enter information:
Name, Address, email, user_id,
Password, planned use of data

• An email will be sent within 2-3
business days to indicate
access has been granted.




                         More than 350 users have registered
Ionospheric profiles availability
Total Electron Content availability
Comparisons with ground-based data
                                From presentation by Stig Syndergaard,
                                UCAR/COSMIC




                    Courtesy of Jiuhou Lei
      First Formosat3 / COSMIC Workshop
      Space Weather Presentations
   4-D Modeling of Ionospheric Electron Density with GNSS Data and the International Reference Ionosphere (IRI), D. Bilitza, M.
    Schmidt and C. Shum C.K. Shum - Ohio State University
   Occultation Measurements of the E-Region Ionosphere                 Paul Strauss - The Aerospace Corporation
   Ionospheric electron density specification using the FORMOSAT-3/COSMIC data Lung-Chih Tsai - Center for Space and Remote
    Sensing Research, NCU
   Validation of COSMIC ionospheric data                 Jiuhou Lei - NCAR/HAO
   Processing of FORMOSAT-3/COSMIC Ionospheric Data at CDAAC Stig Syndergaard - UCAR/COSMIC
   First Observations of the Ionosphere using the Tiny Ionospheric Photometer Clayton Coker - Naval Research Laboratory
   First NRL Results for the TBB/CERTO Radio Beacon Measurements Paul Bernhardt - Naval Research Laboratory
   Does FS3/COSMIC Data Improve Ionospheric Specification?             Craig Baker - AFRL
   Global 3D Imaging of the August 19-20 2006 Storm using COSMIC Data Gary Bust - Atmospheric & Space Technology Research
    Associates
      First Formosat3 / COSMIC Workshop
      Space Weather Presentations (contd.)
   Characteristic Analysis of COSMIC Ionospheric Electron Density Profile: Preliminary Results    Yen-Hsyang Chu
   Observations of Global Ionospheric Sructure by FORMOSAT-3/COSMIC Charles Lin - National Space Organization (NSPO)
   Ionospheric F2-layer Parameter Mapping Based on the FORMOSAT-3/COSMIC Data Lung-Chih Tsai - National Central Univ,
    Taiwan, ROC
   Comparisons of Formosat-3/COSMIC ionospheric data with ground based measurements and model simulations Zhen Zeng -
    UCAR/COSMIC
   On the use of COSMIC podTEC data in the Electron Density Assimilative Model (EDAM)             Matthew Angling - QinetiQ, UK
   Assimilating Formosat-3/COSMIC Ionospheric Data Into A Global Model: Preliminary GAIM Results               Brian Wilson - JPL
   Assimilation of COSMIC Data with the USU GAIM Model               Ludger Scherliess - Utah State University
   Preliminary results from COSMIC Campaigns          Santimay Basu - Air Force Research Laboratory
   Calibration of COSMIC Ionospheric Occultation Profiles using the Arecibo Incoherent Scatter Radar           Michael Kelley -
    Cornell University
   Formosat-3 COSMIC Campaign Observations at Kwajalein Atoll        Chin Lin - Air Force Research Laboratory
A compilation of selected slides presented at the First
FORMOSAT-3/COSMIC Data Users Workshop
Boulder, CO, October 16-18, 2006
&
COSMIC Retreat, October 26-27, 2006
COSMIC NmF2 - 1 week
                                                  From presentation by Santimay Basu, AFRL

TIP observations over large area on 14 Sep 2006
     FM6 pass 1042UT         FM6 pass 0907UT                      FM6 pass 0730UT




     FM3 pass 1050UT         FM3 pass 0914UT                      FM3 pass 0738UT




   FM4-PINH pass 1050UT    FM4-PINH pass 0914UT                FM4-PINH pass 0738UT




     FM1 pass 1140UT         FM1 pass 1005UT                      FM1 pass 0828UT
Maps of NmF2 for COSMIC (dots), Ionosondes (stars), TIEGCM (contour)




COSMIC agree well with ionosonde observations;
Global map of NmF2 revealed from COSMIC is well represented by TIEGCM
model, though TIEGCM shows higher peak density in the low latitude.
  From presentation by Zhen Zeng, NCAR/HAO



Maps of NmF2 for:
 COSMIC (dots),
Ionosondes (stars),
TIEGCM (contour)



COSMIC agree well with
ionosonde observations;
Global map of NmF2
revealed from COSMIC
is well represented by
TIEGCM model, though
TIEGCM shows higher
peak density in the low
latitude.
        NmF2 (left) and HmF2 (right) Comparison between
               TIEGCM and COSMIC on Aug. 2nd




Compared with COSMIC, TIEGCM show smaller peak density in the summer
hemisphere, but larger one in the winter hemisphere;
TIEGCM have lower HmF2 in the polar region.
Sample Comparison Between Arecibo, UCAR, and JPL
             Profiles: Best Agreement
                                    From presentation by Mike Kelley,
                                    Cornell University
COSMIC Occultation Over South Atlantic: 1815 UTC


Black: Cosmic
Blue: IRI
Red: IDA3D

Horizontal Lines
Representation
Error




                            From presentation by Gary S. Bust, Atmospheric &
                            Space Technology Research Associates
                 Precision of GPS RO soundings
                                       Comparison of PPUTLS by Region
       0.6


                  PPUTLS = Precision Parameter of Upper
       0.5
                  Troposphere and Lower Stratosphere, which is the
                  mean absolute differences in the 10-20 km layer


       0.4
PPMT




       0.3




       0.2




       0.1
                                                 0.02% difference in refractivity, which is
                                                 equivalent of 0.05 C in temperature

        0
             0              50                100                 150                200                     250                 300
                                                    Tangent Point Separation Distance (km)
                     PPMT T ropics   PPMT South MidLatitde     PPMT South Polar     PPMT North MidLatitude         PPMT North Polar
Two COSMIC Occultations taking place right next to each other,
passing through nearly the same portion of the atmosphere.
Deviation of pairs of RO soundings separated by less
than 10 km
CHAMP vs. ionosondes (NmF2)

    August 2002           August 2005

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:1
posted:8/22/2011
language:English
pages:69