COSMIC: Constellation Observing System for Meteorology, Ionosphere and Climate Status and Results...

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 launched01:40 UTC 15 April 2006

Three instruments:GPS receiver, TIP, Tri-band beacon

Weather + Space Weather data Global observations of:

Pressure, Temperature, HumidityRefractivityIonospheric Electron DensityIonospheric Scintillation

Demonstrate quasi-operational GPS limb sounding with global coverage in near-real time

Climate Monitoring

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

QuickTime™ and aTIFF (LZW) decompressorare needed to see this picture.LEO

vleo

vGPS

Tangent point

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

QuickTime™ and aTIFF (LZW) decompressorare needed to see this picture.LEO

vleo

vGPS

Tangent point

COSMIC

Radiosondes

COSMIC Soundings in 1 Day

Sec 3, Page 10

Atmospheric refractive index where is the light velocityin a vacuum and is the light velocity in the atmosphere

Refractivity

26

25 103.401073.36.77

f

n

T

P

T

PN ew ×−×+=

vcn /= cv

)1(106 −= nN

• 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

(1) (2) (3)

6 Micro Satellites - USAF Minotaur Rocket Integration

COSMIC launch picture provided by Orbital Sciences Corporation

• 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

Launch on April 14, 2006, Vandenberg AFB, CA

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

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.

00:07 UTC 23 April 2006,

eight days after launch

Comparison of Pairs of COSMIC soundings with GFS analysis

Using COSMIC for Hurricane Ernesto Prediction

Without COSMICWith COSMIC

Results from Hui Liu, NCAR

Using COSMIC for Hurricane Ernesto Prediction

GOES ImageWith COSMIC

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 aTIFF (LZW) decompressor

are needed to see this picture.

GPS Antennas on COSMIC Satellites

Nadir

2 Antennas for orbits, TEC_pod (1-sec), EDP

VleoCOSMIC s/c

High-gain occultation antennasfor atmospheric profiling (50 Hz)

Total electron content data (podTEC)

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



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

P1 Multipath P2 Multipath

Satellite Multipath and Solar Panel Orientation

Pseudorange multipath calibration



Phase-to pseudorange leveling statistics



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

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

€

TEC(p) = 2rN(r)

r2 − p2dr

p

p top∫

First collocated ionospheric profilesFrom 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.

Quiet

Storm

COSMIC #2 GAIM

COSMIC #2 GAIM

Comparisons during quiet and disturbed Conditions

Global Assimilation of Ionospheric MeasurementsUtah State University, (435)797-2962, [email protected];

Universities of Colorado (Boulder), Texas (Dallas), and Washington“Bringing the pieces together”

From presentation by Ludger Scherliess, Utah State University

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

From presentation by Zhen Zeng, NCAR/HAO

QuickTime™ and a decompressor


Using GAIM to correct for gradientsFrom presentation by Stig Syndergaard, UCAR/COSMIC

Courtesy of Zhen Zeng

Scintillation Sensing with COSMIC

No scintillationS4=0.005

ScintillationS4=0.113

GPS/MET SNR data

Where is the sourceRegion of the scintillation?

RED = COSMIC satBLUE = GPS sat

Formosat-3/COSMIC Observations of Scintillations

From presentation by Chin S. Lin, AFRL

Observed TEC Rays in 12-hour period

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/CERTOTEC and Elevation Angle From presentation by

Paul A. Bernhardt, NRL

Input

Data

CDAAC

NESDIS

GTS

NCEP

ECMWF

CWB

UKMO

Canada Met.

JMA

BUFR FilesWMO standard1 file / sounding

Getting COSMIC Results to Weather Centers

Data available to weather centers within < 180 minutes of on-orbit collection

JCSDA

NRL

Neutral Atmosphere Operational Processing

Science & Archive

TACC

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/

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 indicateaccess has been granted.

COSMIC Data Access

More than 350 users have registered

http://www.cosmic.ucar.edu/

http://www.cosmic.ucar.edu/

Ionospheric profiles availability

Total Electron Content availability

Comparisons with ground-based dataFrom 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 WorkshopBoulder, CO, October 16-18, 2006&COSMIC Retreat, October 26-27, 2006

COSMIC NmF2 - 1 week

TIP observations over large area on 14 Sep 2006

FM6 pass 1042UT FM6 pass 0907UT FM6 pass 0730UT


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


From presentation by Santimay Basu, AFRL

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.

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.

Maps of NmF2 for:

COSMIC (dots), Ionosondes (stars), TIEGCM (contour)

From presentation by Zhen Zeng, NCAR/HAO

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 Sample Comparison Between Arecibo, UCAR, and JPL Profiles: Best AgreementProfiles: Best Agreement

From presentation by Mike Kelley, Cornell University

COSMIC Occultation Over South Atlantic: 1815 UTC

Black: CosmicBlue: IRIRed: IDA3D

Horizontal LinesRepresentationError

From presentation by Gary S. Bust, Atmospheric & Space Technology Research Associates

Precision of GPS RO soundings

Comparison of PPUTLS by Region

0

0.1

0.2

0.3

0.4

0.5

0.6

0 50 100 150 200 250 300

Tangent Point Separation Distance (km)

PPMT

PPMT Tropics PPMT South MidLatitde PPMT South Polar PPMT North MidLatitude PPMT North Polar

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

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

COSMIC: Constellation Observing System for Meteorology, Ionosphere and Climate Status and Results...

Documents

Transcript of COSMIC: Constellation Observing System for Meteorology, Ionosphere and Climate Status and Results...