LESIA Observatoire de Paris-PSL CNRS vopdc cdpp Sorbonne Université cnes Université de Paris

STEREO/Waves/LFR-HFR L3 DF Data Collection V1.0

Sunday 5 November 2023, by Baptiste Cecconi, Xavier Bonnin

This collection is contains the daily direction finding (aka goniopolarimetric) Level 3 datasets for the Waves/LFR and Waves/HFR receivers onboard the STEREO-A and STEREO-B spacecraft.

Link to data repository

Description

The data collection contains daily Level 3 direction finding (aka goniopolarimetric) CDF files, derived from the Low Frequency Receiver (LFR) and High Frequency Receiver (HFR) of STEREO-A/Waves and STEREO-B/Waves spacecraft. This data collection has been produced following the goniopolarimetric inversion described in Krupar et al (2012).

Content

The collection is composed of daily CDF files, which variables are described in the table below. They are available in the cdf/ directory, with a directory structure based in the year and month of observation.

CDF Variables descriptions
NameTypeLengthUnitDescription
Epoch CDF_TT2000 (N) ns Epoch encoded as Terrestrial Time on rotating Earth geoid, ns since J2000
SENSOR_CONFIG CDF_BYTE (N,319,3) Dual channel receiver antenna configuration
TIMING CDF_FLOAT (N,319,3) s Temporal offset of each antenna channel configuration
QUALITY_FLAG CDF_INT (N) High level information about the quality of the electric field measurements
INTERPOL_FLAG CDF_INT (N,319) Flag that indicates if the current record is real or interpolated
PSD_V2 CDF_FLOAT (N,319,3,2) V^2/Hz Power spectral density before 1% background subtraction and antenna calibration
PSD_FLUX CDF_FLOAT (N,319) W/m^2/Hz Power spectral density after 1% background subtraction and antenna calibration
PSD_SFU CDF_FLOAT (N,319) sfu Power spectral density after 1% background subtraction and antenna calibration in solar radio flux unit normalized to 1 au
STOKES_I CDF_FLOAT (N,319) W/m^2/Hz Radio flux density
STOKES_Q CDF_FLOAT (N,319) Normalized linear polarization
STOKES_U CDF_FLOAT (N,319) Normalized linear polarization
STOKES_V CDF_FLOAT (N,319) Normalized circular polarization
SOURCE_SIZE CDF_FLOAT (N,319) deg The angular half aperture of the source as seen by a spacecraft (uniform profile)
WAVE_COLATITUDE_RTN CDF_FLOAT (N,319) deg Wave vector colatitude in the Radial-Tangential-Normal (RTN) system
WAVE_AZIMUTH_RTN CDF_FLOAT (N,319) deg Wave vector azimuth in the Radial-Tangential-Normal (RTN) system
WAVE_COLATITUDE_HCI CDF_FLOAT (N,319) deg Wave vector colatitude in the Heliocentric Inertial (HCI) system
WAVE_AZIMUTH_HCI CDF_FLOAT (N,319) deg Wave vector azimuth in the Heliocentric Inertial (HCI) system
WAVE_COLATITUDE_HEE CDF_FLOAT (N,319) deg Wave vector colatitude in the Heliocentric Earth Ecliptic (HEE) system
WAVE_AZIMUTH_HEE CDF_FLOAT (N,319) deg Wave vector azimuth in the Heliocentric Earth Ecliptic (HEE) system
WAVE_COLATITUDE_HEEQ CDF_FLOAT (N,319) deg Wave vector colatitude in the Heliocentric Earth Equatorial (HEEQ) system
WAVE_AZIMUTH_HEEQ CDF_FLOAT (N,319) deg Wave vector azimuth in the Heliocentric Earth Equatorial (HEEQ) system
SC_POS_HCI CDF_FLOAT (N,3) km STEREO spacecraft position in the Heliocentric Inertial (HCI) system in km
SC_POS_HEE CDF_FLOAT (N,3) km STEREO spacecraft position in the Heliocentric Earth Ecliptic (HEE) system in km
SC_POS_HEEQ CDF_FLOAT (N,3) km STEREO spacecraft position in the Heliocentric Earth Equatorial (HEEQ) system in km

The file naming convention is: stX_l3_wav_RRR_yyyymmdd_vVV.cdf

  • X: a 1-letter code for the spacecraft in use (a=STEREO-A; b=STEREO-B);
  • RRR: receiver in use (lfr or hfr).
  • yyyy: Year in 4 digits
  • mm: Month in 2 digits (0-padded)
  • dd: Day in 2 digits (0-padded)
  • VV: version number (2 digits)

Each dataset also contains quicklooks, in the png/ directory, with the same directory structure. Raw IDL Saveset files are also available in the sav/ directory.

Coverage and sampling

  • Time range:
    • 2006 to now for STEREO-A
    • 2006 to 2014 for STEREO-B
  • Time resolution: 30 seconds to 2 minutes.
  • Spectral range: 2.5 kHz to 15 MHz

Acknowledgements

The STEREO/Waves L3 DF data collection has been produced by V Krupar (NASA/GSFC), QN Nugyen X Bonnin, B Cecconi and M Maksimovic (LESIA/Observatoire de Paris-PSL), with the support of CNRS and CNES.

BC was also supported by PADC and EPN2024-RI. The Europlanet 2024 Research Infrastructure (EPN2024-RI) project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 871149.

Contact

Any question or request should be addressed to contact.maser@obspm.fr

References

  • Krupar, V. et al. 2012 Goniopolarimetric inversion using SVD: An application to type III radio bursts observed by STEREO. J. Geophys. Res. 117. doi:10.1029/2011ja017333

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