Status and Plans at CDAAC for Providing Near Real-time ...ftp.emc.ncep.noaa.gov/jcsda/2ndGPSRODUWS/Syndergaard_GPSRO_2005.pdfStatus and Plans at CDAAC for Providing Near Real-time

Status and Plans at CDAAC for ProvidingNear Real-time Ionospheric Data Products

from COSMIC

Stig Syndergaard

William S. Schreiner

Christian Rocken

Douglas C. Hunt

COSMIC Project Office

University Corporation for Atmospheric Research

Second GPS RO Data Users’ Workshop, 22–24 August 2005, Lansdowne, VA

COSMIC Ionospheric Measurements

GPS receiver:{

Total Electron Content (TEC) to all GPS satellites in viewIonospheric radio occultations (profiles) & scintillations

Tiny Ionospheric Photometer (TIP): Ultra-violet emission from ionosphere

Tri-Band Beacon (TBB): TEC & scintillations on satellite-to-ground links

COSMIC Ionospheric Measurements

Total Electron Content measurements:

• High-resolution (1 Hz) TEC to all GPS satellites in view at all times

• Can track up to 12 GPS satellites at the same time (9 aft + 4 fore)

• Useful for global ionospheric tomography and data assimilation

COSMIC Ionospheric Measurements

Ionospheric GPS occultation measurements:

• High-resolution (1 Hz) occultation TEC below orbit altitude

• Ionospheric electron density profiles from orbit altitude and down

• Ionospheric scintillations using the two limb antennas (50 Hz)

COSMIC Ionospheric Measurements

Tiny Ionospheric Photometer measurements:

• Emission (1356 A) due to recombination of oxygen ions and electrons

• Nadir intensity along sub-satellite track – proportional to∫

N 2e dz

• High quality data on night-side – uncertainty about day-side quality

COSMIC Ionospheric Measurements

Tri-Band Beacon measurements:

• Radio signals transmitted from COSMIC at 150, 400, and 1067 MHz

• TEC between the COSMIC satellites and chains of ground receivers

• Amplitude and phase scintillations on the satellite-to-ground links

Ionospheric Data from CHAMP, Oct 29 2003

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CHAMP Langmuir ProbeCHAMP Occultation data

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02:44 UT02:56 UT03:33 UT03:41 UT03:51 UT04:01 UT

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05:49 UT06:06 UT06:22 UT06:34 UT06:42 UT06:58 UT

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16 Months of Data – 44 000 Comparisons

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Electron density (cm-3) - Langmuir Probe

RMS = 1.3•105 cm-3

Correlation = 0.95

CHAMP Differential Code Bias

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Day of year, 2003

next day prediction

• Based on simple assumptions (e.g., azimuthal symmetry above LEO)

• Single day estimates based on 24 hr average – next day prediction(for near real-time processing) based on smoothing over 50 days

• For COSMIC there will be 6×2 DCBs to solve for

CHAMP Ionospheric Scintillation Map

Status and Plans for COSMIC

Total Electron Content measurements

Plans: Quality control, outlier detection, cycle-slip correction, and Differential Code Bias calibration

Status: Prototype working for CHAMP data – not yet integrated in CDAAC processing system

Ionospheric GPS occultation measurements

Plans: Reducing effects from horizontal gradients in profile retrievals using a model (e.g., GAIM)

Status: Profiles derived via Abel inversion •• Scintillation maps not yet integrated in CDAAC system

Tiny Ionospheric Photometer measurements

Plans: Providing radiances derived from raw data (counts) as well as pointing direction •• CombiningTIP data and GPS occultation data for “in-plane” occultations (Naval Research Lab)

Status: Work on radiance retrieval codes (in collaboration with NRL) in progress

Tri-Band Beacon measurements

Plans: Plans regarding processing of TBB data are not in place •• One TBB receiver may be installedon the top of the roof at UCAR – CDAAC will process data from this one

Status: Ongoing work to install receiver chains in various countries all over the world (NRL)

COSMIC Data Products and Formats

COSMIC Data Products and Formats

Data description Level/Type Main products Resolution Format Latency

GPS receiver data fromthe POD antennae – onefile per COSMIC PODantenna per dump

level 1apodGps

- time- phases- pseudo-ranges- SNRs

temporal:1 sec

RINEX . 115 min

LEO attitude and orbits(from real time naviga-tion solutions) – one fileper COSMIC satellite perdump

level 1aleoAtt

- time- attitude param.- position- velocity

temporal:10 sec

ASCII . 115 min

Precise LEO orbits – onefile per COSMIC satelliteper dump

level 1bleoOrb

- time- position- velocity

temporal:1 min

SP3 . 145 min

IGS Ultra-Rapid GPS or-bits (including 24 hr pre-dicted orbits) – one fileevery 6 hr

level 1agpsOrb

- time- position- velocity

temporal:15 min

SP3 0 min

Absolute TEC to all GPSsatellites in view (QCand bias resolved) – onefile per COSMIC satelliteper GPS satellite per arc

level 1bionTec

- time- Rx & Tx pos.- absolute TEC- code biases

temporal:1 sec

NetCDF . 115 min

COSMIC Data Products and Formats

Data description Level/Type Main products Resolution Format Latency

GPS receiver data fromthe POD antennae – onefile per COSMIC PODantenna per dump

level 1apodGps

- time- phases- pseudo-ranges- SNRs

temporal:1 sec

RINEX . 115 min

LEO attitude and orbits(from real time naviga-tion solutions) – one fileper COSMIC satellite perdump

level 1aleoAtt

- time- attitude param.- position- velocity

temporal:10 sec

ASCII . 115 min

Precise LEO orbits – onefile per COSMIC satelliteper dump

level 1bleoOrb

- time- position- velocity

temporal:1 min

SP3 . 145 min

IGS Ultra-Rapid GPS or-bits (including 24 hr pre-dicted orbits) – one fileevery 6 hr

level 1agpsOrb

- time- position- velocity

temporal:15 min

SP3 0 min

Absolute TEC to all GPSsatellites in view (QCand bias resolved) – onefile per COSMIC satelliteper GPS satellite per arc

level 1bionTec

- time- Rx & Tx pos.- absolute TEC- code biases

temporal:1 sec

NetCDF . 115 min

COSMIC Data Products and Formats

Data description Level/Type Main products Resolution Format Latency

GPS receiver data fromthe POD antennae – onefile per COSMIC PODantenna per dump

level 1apodGps

- time- phases- pseudo-ranges- SNRs

temporal:1 sec

RINEX . 115 min

LEO attitude and orbits(from real time naviga-tion solutions) – one fileper COSMIC satellite perdump

level 1aleoAtt

- time- attitude param.- position- velocity

temporal:10 sec

ASCII . 115 min

Precise LEO orbits – onefile per COSMIC satelliteper dump

level 1bleoOrb

- time- position- velocity

temporal:1 min

SP3 . 145 min

IGS Ultra-Rapid GPS or-bits (including 24 hr pre-dicted orbits) – one fileevery 6 hr

level 1agpsOrb

- time- position- velocity

temporal:15 min

SP3 0 min

Absolute TEC to all GPSsatellites in view (QCand bias resolved) – onefile per COSMIC satelliteper GPS satellite per arc

level 1bionTec

- time- Rx & Tx pos.- absolute TEC- code biases

temporal:1 sec

NetCDF . 115 min

COSMIC Data Products and Formats

Data description Level/Type Main products Resolution Format Latency

GPS receiver data fromthe POD antennae – onefile per COSMIC PODantenna per dump

level 1apodGps

- time- phases- pseudo-ranges- SNRs

temporal:1 sec

RINEX . 115 min

LEO attitude and orbits(from real time naviga-tion solutions) – one fileper COSMIC satellite perdump

level 1aleoAtt

- time- attitude param.- position- velocity

temporal:10 sec

ASCII . 115 min

Precise LEO orbits – onefile per COSMIC satelliteper dump

level 1bleoOrb

- time- position- velocity

temporal:1 min

SP3 . 145 min

IGS Ultra-Rapid GPS or-bits (including 24 hr pre-dicted orbits) – one fileevery 6 hr

level 1agpsOrb

- time- position- velocity

temporal:15 min

SP3 0 min

Absolute TEC to all GPSsatellites in view (QCand bias resolved) – onefile per COSMIC satelliteper GPS satellite per arc

level 1bionTec

- time- Rx & Tx pos.- absolute TEC- code biases

temporal:1 sec

NetCDF . 115 min

COSMIC Data Products and Formats

Data description Level/Type Main products Resolution Format Latency

GPS receiver data fromthe POD antennae – onefile per COSMIC PODantenna per dump

level 1apodGps

- time- phases- pseudo-ranges- SNRs

temporal:1 sec

RINEX . 115 min

LEO attitude and orbits(from real time naviga-tion solutions) – one fileper COSMIC satellite perdump

level 1aleoAtt

- time- attitude param.- position- velocity

temporal:10 sec

ASCII . 115 min

Precise LEO orbits – onefile per COSMIC satelliteper dump

level 1bleoOrb

- time- position- velocity

temporal:1 min

SP3 . 145 min

IGS Ultra-Rapid GPS or-bits (including 24 hr pre-dicted orbits) – one fileevery 6 hr

level 1agpsOrb

- time- position- velocity

temporal:15 min

SP3 0 min

Absolute TEC to all GPSsatellites in view (QCand bias resolved) – onefile per COSMIC satelliteper GPS satellite per arc

level 1bionTec

- time- Rx & Tx pos.- absolute TEC- code biases

temporal:1 sec

NetCDF . 115 min

COSMIC Data Products and Formats

Data description Level/Type Main products Resolution Format Latency

Ionospheric occultationexcess phases and ampli-tudes – one file per GPSoccultation

level 1bionPhs

- time- SNRs- Rx & Tx pos.- Rx & Tx vel.- excess phases

temporal:1 sec

NetCDF . 145 min

Ionospheric occultationprofiles from orbit alti-tude and down – one fileper GPS occultation

level 2ionPrf

- time- lat., lon.- tangent altitude- occ. TEC- electron dens.

vertical:2-3 km

NetCDF . 145 min

Raw TIP (Tiny Iono-spheric Photometer)nadir radiance data –one file per COSMICsatellite per dump

level 1atipBin

- time- counts

temporal:seconds

TIPnativebinary

. 115 min

Radiances from the TIP– one file per COSMICsatellite per dump

level 1btipLv1

- time- counts- calib. coeff.- Rx position- surface lat., lon.- radiances

temporal:seconds

NetCDF . 115 min

COSMIC Data Products and Formats

Data description Level/Type Main products Resolution Format Latency

Ionospheric occultationexcess phases and ampli-tudes – one file per GPSoccultation

level 1bionPhs

- time- SNRs- Rx & Tx pos.- Rx & Tx vel.- excess phases

temporal:1 sec

NetCDF . 145 min

Ionospheric occultationprofiles from orbit alti-tude and down – one fileper GPS occultation

level 2ionPrf

- time- lat., lon.- tangent altitude- occ. TEC- electron dens.

vertical:2-3 km

NetCDF . 145 min

Raw TIP (Tiny Iono-spheric Photometer)nadir radiance data –one file per COSMICsatellite per dump

level 1atipBin

- time- counts

temporal:seconds

TIPnativebinary

. 115 min

Radiances from the TIP– one file per COSMICsatellite per dump

level 1btipLv1

- time- counts- calib. coeff.- Rx position- surface lat., lon.- radiances

temporal:seconds

NetCDF . 115 min

COSMIC Data Products and Formats

Data description Level/Type Main products Resolution Format Latency

Ionospheric occultationexcess phases and ampli-tudes – one file per GPSoccultation

level 1bionPhs

- time- SNRs- Rx & Tx pos.- Rx & Tx vel.- excess phases

temporal:1 sec

NetCDF . 145 min

Ionospheric occultationprofiles from orbit alti-tude and down – one fileper GPS occultation

level 2ionPrf

- time- lat., lon.- tangent altitude- occ. TEC- electron dens.

vertical:2-3 km

NetCDF . 145 min

Raw TIP (Tiny Iono-spheric Photometer)nadir radiance data –one file per COSMICsatellite per dump

level 1atipBin

- time- counts

temporal:seconds

TIPnativebinary

. 115 min

Radiances from the TIP– one file per COSMICsatellite per dump

level 1btipLv1

- time- counts- calib. coeff.- Rx position- surface lat., lon.- radiances

temporal:seconds

NetCDF . 115 min

COSMIC Data Products and Formats

Data description Level/Type Main products Resolution Format Latency

Ionospheric occultationexcess phases and ampli-tudes – one file per GPSoccultation

level 1bionPhs

- time- SNRs- Rx & Tx pos.- Rx & Tx vel.- excess phases

temporal:1 sec

NetCDF . 145 min

Ionospheric occultationprofiles from orbit alti-tude and down – one fileper GPS occultation

level 2ionPrf

- time- lat., lon.- tangent altitude- occ. TEC- electron dens.

vertical:2-3 km

NetCDF . 145 min

Raw TIP (Tiny Iono-spheric Photometer)nadir radiance data –one file per COSMICsatellite per dump

level 1atipBin

- time- counts

temporal:seconds

TIPnativebinary

. 115 min

Radiances from the TIP– one file per COSMICsatellite per dump

level 1btipLv1

- time- counts- calib. coeff.- Rx position- surface lat., lon.- radiances

temporal:seconds

NetCDF . 115 min

Summary

• Three instruments on board each COSMIC satellite will provide iono-

spheric data:

– GPS receiver: TEC, electron density profiles, and scintillations

– TIP: Nadir intensity from radiative recombination emission along

the sub-satellite track

– TBB: TEC and scintillations on satellite-to-ground links

• COSMIC will provide an unprecedented large amount of ionospheric

data useful for data assimilation into space weather models and

ionospheric research in general

• Feedback very welcome on planed near real-time ionospheric data

products and formats

• We also need to discuss ionospheric data distribution. . .