2.7.1 spase://NASA/NumericalData/ParkerSolarProbe/FIELDS/RFS_LFR/Level3/QuasiThermalNoise/VariableCadence NASA NumericalData Radio Frequency Spectrometer LFR Quasi-thermal noise, Data 2025-07-07T12:34:56.789 2025-07-07T12:34:56.789 Initial release of metadata, ADAPT generated, LFB; modified, SAB 2026-05-14T00:00:00.000 Added parameter choices, SAB Quasi-thermal noise (QTN) spectroscopy is an efficient tool for measuring in situ macroscopic plasma properties in space, using a passive wave receiver at the ports of an electric antenna [1]. The Radio Frequency Spectrometer (RFS) is a dual channel digital spectrometer, designed for both remote sensing of radio waves and in situ measurement of electrostatic fluctuations using signals from the V1-V4 electric field antennas [2]. Usually, the two RFS channels record differences between V1-V2 and V3-V4 antennas (dipole mode). It allows us to retrieve plasma properties independently by two sets of antennas. The plasma line is automatically identified in a frequency range determined by the density model based on spacecraft distance from the Sun. The frequency range is manually adjusted for intervals when the plasma line occurs at lower or higher frequencies than predicted. We assume that the plasma line is well identified if detected at the same frequency by the V1-V2 and V3-V4 dipoles simultaneously. We assume that the plasma frequency is equal to the geometric mean of the plasma line and the preceding frequency channel. In other words, the plasma frequency corresponds to the steepest positive slope below the plasma line. The provided error bars are calculated from the frequency resolution of the RFS instrument. [1] Meyer-Vernet, N., Issautier, K., and Moncuquet, M. (2017). Quasi-thermal noise spectroscopy: The art and the practice. Journal of Geophysical Research: Space Physics, 122, 7925-7945. https://doi.org/10.1002/2017ja024449 [2] Bale, S. D., Goetz, K., Harvey, P. R., Turin, P., Bonnell, J. W., Dudok de Wit, T., et al. (2016). The FIELDS instrument suite for Solar probe plus. Measuring the coronal plasma and magnetic field, plasma waves and turbulence, and radio signatures of Solar transients. Space Science Reviews, 204(1-4), 49-82. https://doi.org/10.1007/s11214-016-0244-5 This project acknowledges the Parker Solar Probe FIELDS instrument team and the FIELDS science data center for providing these solar wind plasma measurements.. NASA open data policy applies. Consultation with the instrument team is strongly recommended. Bale, Stuart D; Krupar, Vratislav; Pulupa, Marc; Quinn, Timothy; Schroeder, Peter 2020-01-01T00:00:00 NASA Space Physics Data Facility spase://SMWG/Person/Stuart.D.Bale PrincipalInvestigator spase://SMWG/Person/Robert.M.Candey MetadataContact spase://SMWG/Person/Scott.Boardsen MetadataContact FIELDS instrument paper https://link.springer.com/article/10.1007/s11214-016-0244-5 PSP/FIELDS/RFS/LFR data available at en SSL FIELDS data website http://fields.ssl.berkeley.edu/data/ PSP/FIELDS/RFS/LFR data available at en The Quasi-thermal noise (QTN) spectroscopy paper https://doi.org/10.1002/2017JA024449 PSP/FIELDS/RFS/LFR data available at en spase://SMWG/Repository/NASA/GSFC/SPDF/CDAWeb Online FTPS from SPDF (not with most browsers) ftps://spdf.gsfc.nasa.gov/pub/data/psp/fields/l3/rfs_lfr_qtn/ PSP_FLD_L3_RFS_LFR_QTN Access to Data in CDF Format via ftps from SPDF HTTPS from SPDF https://spdf.gsfc.nasa.gov/pub/data/psp/fields/l3/rfs_lfr_qtn/ PSP_FLD_L3_RFS_LFR_QTN Access to Data in CDF Format via https from SPDF CDAWeb https://cdaweb.gsfc.nasa.gov/cgi-bin/eval2.cgi?dataset=PSP_FLD_L3_RFS_LFR_QTN&index=sp_phys PSP_FLD_L3_RFS_LFR_QTN Access to ASCII, CDF, and Plots via NASA/GSFC CDAWeb CDF None None psp_fld_l3_rfs_lfr_qtn_%Y%m%d_%Y%m%d_%Q.cdf Please acknowledge the Principal Investigator Stuart D. Bale (bale@ssl.berkeley.edu). Please acknowledge the Data Providers and CDAWeb when using these Data. spase://SMWG/Repository/NASA/GSFC/SPDF Online Open CDAWeb Programmatic Data Access https://cdaweb.gsfc.nasa.gov/WS/cdasr/1/dataviews/sp_phys/datasets/PSP_FLD_L3_RFS_LFR_QTN/clientLibraryExample/ PSP_FLD_L3_RFS_LFR_QTN Access to this data from common programming environments. Note: this AccessInformation element was added by HDPWS. Binary Please acknowledge the Principal Investigator Stuart D. Bale (bale@ssl.berkeley.edu). Please acknowledge the Data Providers and CDAWeb when using these Data. spase://SMWG/Repository/NASA/GSFC/SPDF/CDAWeb Online CDAWeb HAPI Server https://cdaweb.gsfc.nasa.gov/hapi PSP_FLD_L3_RFS_LFR_QTN Web Service to this product using the HAPI interface. CSV Please acknowledge the Principal Investigator Stuart D. Bale (bale@ssl.berkeley.edu). Please acknowledge the Data Providers and CDAWeb when using these Data. Calibrated spase://SMWG/Instrument/ParkerSolarProbe/RFS ThermalPlasma 2018-10-19T00:11:48.000 2024-04-08T07:29:54.000 PT99999.999S Heliosphere Heliosphere.Inner Heliosphere.NearEarth Sun.Corona Epoch Epoch CDF TT2000 time [ns] ns 1.0e-9>s Epoch LinearScale 2010-01-01T00:00:00.000000000 2049-12-31T23:59:59.999999999 9999-12-31T23:59:59.999999999 Orientation Electron density Time series defined by using: Epoch N_elec QTN electron density PT99999.999S cm^-3 TimeSeries Electron density E12.2 LinearScale 1.00e-02 1.00e+04 -1.0e+31 Electron Scalar NumberDensity Electron density, lower uncertainty Time series defined by using: Epoch N_elec_deltalow Lower uncertainty associated with QTN electron density PT99999.999S cm^-3 TimeSeries Electron density, lower uncertainty E12.2 LinearScale 1.00e-02 1.00e+04 -1.0e+31 Electron Scalar NumberDensity Electron density, upper uncertainty Time series defined by using: Epoch N_elec_deltahigh Upper uncertainty associated with QTN electron density PT99999.999S cm^-3 TimeSeries Electron density, upper uncertainty E12.2 LinearScale 1.00e-02 1.00e+04 -1.0e+31 Electron Scalar NumberDensity Data quality flag Time series defined by using: Epoch N_elec_dqf Array of density data quality indicators PT99999.999S Data quality flag I3 LinearScale 0 5 255 Housekeeping Frequency Range, Lower Boundary Time series defined by using: Epoch Frequency_low Lower boundary of the frequency range with the peak PT99999.999S Hz Frequency Range, Lower Boundary E12.2 LinearScale 0.00e+00 2.00e+07 -1.0e+31 Housekeeping Frequency Range, Upper Boundary Time series defined by using: Epoch Frequency_high Upper boundary of the frequency range with the peak PT99999.999S Hz Frequency Range, Lower Boundary E12.2 LinearScale 0.00e+00 2.00e+07 -1.0e+31 Housekeeping Electron density (channel 0) Time series defined by using: Epoch N_elec_ch0 QTN electron density at channel 0 PT99999.999S cm^-3 TimeSeries Electron density (channel 0) E12.2 LinearScale 1.00e-02 1.00e+04 -1.0e+31 Electron Scalar NumberDensity Electron density (channel 0), lower uncertainty Time series defined by using: Epoch N_elec_ch0_deltalow Lower uncertainty associated with QTN electron density at channel 0 PT99999.999S cm^-3 TimeSeries Electron density (channel 0), lower uncertainty E12.2 LinearScale 1.00e-02 1.00e+04 -1.0e+31 Electron Scalar NumberDensity Electron density (channel 0), upper uncertainty Time series defined by using: Epoch N_elec_ch0_deltahigh Upper uncertainty associated with QTN electron density at channel 0 PT99999.999S cm^-3 TimeSeries Electron density, upper uncertainty (channel 0) E12.2 LinearScale 1.00e-02 1.00e+04 -1.0e+31 Electron Scalar NumberDensity Electron density (channel 1) Time series defined by using: Epoch N_elec_ch1 QTN electron density at channel 1 PT99999.999S cm^-3 TimeSeries Electron density (channel 1) E12.2 LinearScale 1.00e-02 1.00e+04 -1.0e+31 Electron Scalar NumberDensity Electron density (channel 1), lower uncertainty Time series defined by using: Epoch N_elec_ch1_deltalow Lower uncertainty associated with QTN electron density at channel 1 PT99999.999S cm^-3 TimeSeries Electron density, lower uncertainty (channel 1) E12.2 LinearScale 1.00e-02 1.00e+04 -1.0e+31 Electron Scalar NumberDensity Electron density (channel 1), upper uncertainty Time series defined by using: Epoch N_elec_ch1_deltahigh Upper uncertainty associated with QTN electron density at channel 1 PT99999.999S cm^-3 TimeSeries Electron density, upper uncertainty E12.2 LinearScale 1.00e-02 1.00e+04 -1.0e+31 Electron Scalar NumberDensity Position in HEEQ coordinates (X-component) Time series defined by using: Epoch HEEQ_X Position vector in HEEQ coordinates (Define Rs = 695700km) (X-component) PT99999.999S Rs TimeSeries X (HEEQ) E12.2 LinearScale -3.00e+02 3.00e+02 -1.0e+31 Scalar Positional Position in HEEQ coordinates (Y-component) Time series defined by using: Epoch HEEQ_Y Position vector in HEEQ coordinates (Define Rs = 695700km) (Y-component) PT99999.999S Rs TimeSeries Y (HEEQ) E12.2 LinearScale -3.00e+02 3.00e+02 -1.0e+31 Scalar Positional Position in HEEQ coordinates (Z-component) Time series defined by using: Epoch HEEQ_Z Position vector in HEEQ coordinates (Define Rs = 695700km) (Z-component) PT99999.999S Rs TimeSeries Z (HEEQ) E12.2 LinearScale -3.00e+02 3.00e+02 -1.0e+31 Scalar Positional