COSMIC: Constellation Observing System for Meteorology, Ionosphere and Climate

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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
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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

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COSMIC (Constellation Observing System for
Meteorology, Ionosphere and Climate)

• 6 Satellites launched
• 0140 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

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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
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The velocity of GPS relative to LEO must be
estimated to 0.2 mm/sec (20 ppb) to determine
precise temperature profiles
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COSMIC Soundings in 1 Day
COSMIC Radiosondes
Sec 3, Page 10
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Atmospheric refractive index
where is the light velocity in a vacuum
and is the light velocity in the
atmosphere Refractivity
(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

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6 Micro Satellites - USAF Minotaur Rocket
Integration
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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
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COSMIC Current Constellation
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COSMIC - Final Deployment

• 6 Planes
• 71 Degrees inclination
• 800 Km
• 2500 Soundings per day
• Latency 50-140 minutes from observation to NOAA

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Some Neutral Atmosphere Results
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0007 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
0007 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
20.4S and 95.4W.
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Comparison of Pairs of COSMIC soundings with GFS
analysis
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Using COSMIC for Hurricane Ernesto Prediction
With COSMIC
Without COSMIC
Results from Hui Liu, NCAR
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Using COSMIC for Hurricane Ernesto Prediction
With COSMIC
GOES Image
GOES Image from Tim Schmitt, SSEC
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Southern Hemisphere Forecast Improvements from
COSMIC Data
Sean Healey, ECMWF
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Northern Hemisphere Forecast Improvements from
COSMIC Data
Sean Healey, ECMWF
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Space Weather
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GPS Antennas on COSMIC Satellites
Nadir
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Total electron content data (podTEC)

• COSMIC generates 2500 - 3000 TEC arcs per day
• Sampling rate is 1 -sec

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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

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Satellite Multipath and Solar Panel Orientation
P1 Multipath
P2 Multipath
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Pseudorange multipath calibration
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Phase-to pseudorange leveling statistics
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COSMIC DCBs for 1 year
Quality of absolute TEC from COSMIC 2 TECU
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Comparison of Calibrated Slant TEC Measurements
for June 26, 2006
Elev cutoff angle differences?
Good match
Negative TEC
Calib. Different

• An example of comparison of calibrated TEC
  between JPL and UCAR
• There appears to be a 2-3 TECU bias between JPL
  and UCAR slant TEC
• Negative TEC, differences between UCAR and JPL
  elevation cutoff angles
• Similar data volumes between JPL and UCAR

From presentation by Brian Wilson, JPL
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Observed TEC Rays in 12-hour period
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observed in Local time
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Latency of COSMIC podTec data
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Profile retrieval method

• ?TEC solid - dashed Schreiner et al., 1999
• Inverted via onion-peeling approach to obtain
  electron density N(r)
• Assumption of spherical symmetry

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First collocated ionospheric profiles
From presentation by Stig Syndergaard, UCAR/COSMIC
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Comparisons with ISR dataLei et al., submitted
to JGR 2007
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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.
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From presentation by Ludger Scherliess, Utah
State University
Comparisons during quiet and disturbed Conditions
COSMIC 2 GAIM
Quiet
COSMIC 2 GAIM
Storm
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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
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Using GAIM to correct for gradients
From presentation by Stig Syndergaard, UCAR/COSMIC
Courtesy of Zhen Zeng
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Scintillation Sensing with COSMIC
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Formosat-3/COSMIC Observations of Scintillations
From presentation by Chin S. Lin, AFRL
RED COSMIC sat BLUE GPS sat
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Observed TEC Rays in 12-hour period
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TIP 135.6-nm passes 14 Sep 2006FM1 FM3 FM6 0-24
UT (2100 LT)
From presentation by Clayton Coker, NRL
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Chung-Li COSMIC TBB/CERTOTEC and Elevation Angle
From presentation by Paul A. Bernhardt, NRL
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Getting COSMIC Results to Weather Centers
Neutral Atmosphere Operational Processing
JCSDA
TACC
NCEP
Input Data
NESDIS
CDAAC
ECMWF
CWB
GTS
UKMO
BUFR Files WMO standard 1 file / sounding
JMA
Canada Met.
Science Archive
NRL
Data available to weather centers within lt 180
minutes of on-orbit collection
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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

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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/
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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
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Ionospheric profiles availability
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Total Electron Content availability
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Comparisons with ground-based data
From presentation by Stig Syndergaard, UCAR/COSMIC
Courtesy of Jiuhou Lei
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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

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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

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A compilation of selected slides presented at the
First FORMOSAT-3/COSMIC Data Users
WorkshopBoulder, CO, October 16-18,
2006COSMIC Retreat, October 26-27, 2006
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COSMIC NmF2 - 1 week
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TIP observations over large area on 14 Sep 2006
From presentation by Santimay Basu, AFRL
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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.
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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.
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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.
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Sample Comparison Between Arecibo, UCAR, and JPL
Profiles Best Agreement
From presentation by Mike Kelley, Cornell
University
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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
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Precision of GPS RO soundings
PPUTLS Precision Parameter of Upper Troposphere
and Lower Stratosphere, which is the mean
absolute differences in the 10-20 km layer
0.02 difference in refractivity, which is
equivalent of 0.05 C in temperature
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Two COSMIC Occultations taking place right next
to each other, passing through nearly the same
portion of the atmosphere.
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Deviation of pairs of RO soundings separated by
less than 10 km
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CHAMP vs. ionosondes (NmF2)
August 2002
August 2005