Transcript COSMIC: Constellation Observing System for Meteorology, Ionosphere and Climate

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
Qu i ck Ti me ™a nd a
TIF F (LZW)d ec om pres so r
a re ne ed ed to s ee th i s pi c tu re.
LEO
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
The LEO tracks the GPS phase
while the signal is occulted to
determine the Doppler
Tangent point
vGPS
Qu i ck Ti me ™a nd a
TIF F (LZW)d ec om pres so r
a re ne ed ed to s ee th i s pi c tu re.
LEO
vleo
The velocity of GPS relative to
LEO must be estimated to ~0.2
mm/sec (20 ppb) to determine
precise temperature profiles
The LEO tracks the GPS phase
while the signal is occulted to
determine the Doppler
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  106 (n  1)
P
5 Pw
6 ne
N  77.6  3.73  10 2  40.3  10 2
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™ and a
TIFF (LZW) decompressor
are needed to see this picture.
GPS Antennas on COSMIC Satellites
2 Antennas for orbits, TEC_pod (1-sec), EDP
COSMIC s/c
High-gain occultation antennas
for atmospheric profiling
(50 Hz)
Nadir
Vleo
QuickTime™ and a
TIFF (LZW) decompressor
are needed 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 needed 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) decompressor
are needed to see this picture.
Phase-to pseudorange leveling statistics
QuickTime™ and a
TIFF (LZW) decompressor
are needed 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™ and a
TIFF (LZW) decompressor
are needed to see this picture.
Profile retrieval method
TEC = solid - dashed
TEC( p) = 2




[Schreiner et al., 1999]
p top
rN(r)
p
r 2  p2
dr
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 midlat, 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 Universit y, ( 435 )7 97 -2 962 , [email protected] u;
Universit ies of Colorado ( Boulder), Texas ( Dallas), and Washingt on
“ Bringing t he pieces 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™ and a
decompressor
are needed to see this picture.
Using GAIM to correct for gradients
From presentation by Stig Syndergaard,
UCAR/COSMIC
Courtesy of Zhen Zeng
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
Scintillation Sensing with COSMIC
No scintillation
S4=0.005
Scintillation
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™ and a
TIFF (LZW) decompressor
are needed 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
TEC and Elevation Angle
From presentation by
Paul A. Bernhardt, NRL
Getting COSMIC Results to Weather Centers
Neutral Atmosphere Operational Processing
JCSDA
TACC
I
n
p
u
t
D
a
t
a
C
D
A
A
C
BUFR Files
WMO standard
1 file / sounding
Science & Archive
N
E
S
D
I
S
NCEP
ECMWF
GTS
CWB
UKMO
JMA
NRL
Canada Met.
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
Troposphere and Lower Stratosphere, which is the
mean absolute differences in the 10-20 km layer
0.5
PPMT
0.4
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 Tropics
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