PSP FIELDS Digital Fields Board (DFB), SCMXlfhg ⨯ SCMXlfhg cross spectra data:
The DFB is the low frequency, less than 75 kHz, component of the FIELDS experiment on the Parker Solar Probe spacecraft, see reference [1] below. For a full description of the FIELDS experiment, see reference [2]. For a description of the DFB, see reference [3].
DFB DC cross spectra data for a pair of input channels consist of:
where all as a function of frequency and time. The last two terms are describedcoherence and phase are defined in [3].
These cross spectra are averaged in both frequency and time as described in [3]. The cross spectra have either 56 or 96 bins (selectable) with the bin central frequencies reported in the metadata.
The Level 2 data products contained in this data file have been calibrated for:
Note that compensation for the DFB digital filters will introduce a non-physical positively sloped power trend at high frequencies when the non-corrected signal is dominated by noise. This effect should be examined carefully when determining spectral slopes and features at the highest frequencies. Calibrations for the FIELDS preamplifiers have not been implemented as the preamplifier response is flat and equal to one through the DFB frequency range. Corrections for plasma sheath impedance gain and antenna effective length have not been applied to voltage sensor signals. These corrections will be applied in the Level 3 DFB data products. Therefore, all voltage sensor quantities when present in these Level 2 data products are expressed by using units of Volts squared per Hertz. Likewise, all magnetic field quantities when present in these Level 2 data product are expressed by using units of nanoTesla squared per Hertz. The units for phase are degrees.
The Level 2 voltage data products contained in this data file are expressed in sensor coordinates: e.g. dV12, dV34 for voltage measurements. For solar orbits 1 and 2, the search coil magnetometer cross spectra data are rotated into a non-intuitive coordinate system with components [d,e,f]. For solar orbits 3 and beyond, the magnetic field cross spectra data are expressed by using search coil magnetometer sensor coordinates with components [u,v,w].
To rotate from [d,e,f] coordinates to [u,v,w] search coil sensor coordinates, use the following matrix, written in IDL notation, and the following equation: spectra_uvw_vector = R ## spectra_def_vector.
R = [[ 0.46834856, -0.81336422 , 0.34509170]
[ -0.66921924, -0.071546954, 0.73961249]
[ -0.57688408, -0.57733845 , -0.57782790]]
For some orbits, sufficient spectral information exists in the auto spectra and cross spectra to determine wave ellipticity, planarity, and wave normal angles. One method for accomplishing this is presented in reference [4].
Time resolution of the DFB DC cross spectral data can vary by multiples of 2^N. During encounter (when PSP is within 0.25 AU of the Sun), cadence for the DFB DC cross spectra is typically 30 NYseconds [2]. Timestamps correspond to the center time of each window.
References:
Version:2.4.0
PSP FIELDS Digital Fields Board (DFB), SCMXlfhg ⨯ SCMXlfhg cross spectra data:
The DFB is the low frequency, less than 75 kHz, component of the FIELDS experiment on the Parker Solar Probe spacecraft, see reference [1] below. For a full description of the FIELDS experiment, see reference [2]. For a description of the DFB, see reference [3].
DFB DC cross spectra data for a pair of input channels consist of:
where all as a function of frequency and time. The last two terms are describedcoherence and phase are defined in [3].
These cross spectra are averaged in both frequency and time as described in [3]. The cross spectra have either 56 or 96 bins (selectable) with the bin central frequencies reported in the metadata.
The Level 2 data products contained in this data file have been calibrated for:
Note that compensation for the DFB digital filters will introduce a non-physical positively sloped power trend at high frequencies when the non-corrected signal is dominated by noise. This effect should be examined carefully when determining spectral slopes and features at the highest frequencies. Calibrations for the FIELDS preamplifiers have not been implemented as the preamplifier response is flat and equal to one through the DFB frequency range. Corrections for plasma sheath impedance gain and antenna effective length have not been applied to voltage sensor signals. These corrections will be applied in the Level 3 DFB data products. Therefore, all voltage sensor quantities when present in these Level 2 data products are expressed by using units of Volts squared per Hertz. Likewise, all magnetic field quantities when present in these Level 2 data product are expressed by using units of nanoTesla squared per Hertz. The units for phase are degrees.
The Level 2 voltage data products contained in this data file are expressed in sensor coordinates: e.g. dV12, dV34 for voltage measurements. For solar orbits 1 and 2, the search coil magnetometer cross spectra data are rotated into a non-intuitive coordinate system with components [d,e,f]. For solar orbits 3 and beyond, the magnetic field cross spectra data are expressed by using search coil magnetometer sensor coordinates with components [u,v,w].
To rotate from [d,e,f] coordinates to [u,v,w] search coil sensor coordinates, use the following matrix, written in IDL notation, and the following equation: spectra_uvw_vector = R ## spectra_def_vector.
R = [[ 0.46834856, -0.81336422 , 0.34509170]
[ -0.66921924, -0.071546954, 0.73961249]
[ -0.57688408, -0.57733845 , -0.57782790]]
For some orbits, sufficient spectral information exists in the auto spectra and cross spectra to determine wave ellipticity, planarity, and wave normal angles. One method for accomplishing this is presented in reference [4].
Time resolution of the DFB DC cross spectral data can vary by multiples of 2^N. During encounter (when PSP is within 0.25 AU of the Sun), cadence for the DFB DC cross spectra is typically 30 NYseconds [2]. Timestamps correspond to the center time of each window.
References:
| Role | Person | StartDate | StopDate | Note | |
|---|---|---|---|---|---|
| 1. | PrincipalInvestigator | spase://SMWG/Person/Stuart.D.Bale | |||
| 2. | MetadataContact | spase://SMWG/Person/Robert.M.Candey | |||
| 3. | MetadataContact | spase://SMWG/Person/Lee.Frost.Bargatze |
Parker Solar Probe, PSP, FIELDS Instrument Suite Description: Bale, S.D., Goetz, K., Harvey, P.R. et al., The FIELDS Instrument Suite for Solar Probe Plus, Space Sci Rev 204, 49-82 (2016)
Parker Solar Probe, PSP, FIELDS Instrument Suite, Digital Fields Board, DFB, Description: Malaspina, D.M., Ergun, R.E., Bolton, M. et al., The Digital Fields Board for the FIELDS Instrument Suite on the Solar Probe Plus Mission: Analog and Digital signal Processing, JGR Space Physics, 121, 5088-5096 (2016)
Parker Solar Probe, PSP, FIELDS Instrument Suite, Data Description and Access, Spacecraft Operations Center, SOC, Web Site, UC Berkeley
Parker Solar Probe, PSP, FIELDS Instrument Suite, Rules of the Road, Spacecraft Operations Center, SOC, Web Site, UC Berkeley
Parker Solar Probe, PSP, Mission Overview, hosted by the Applied Physics Laboratory, Johns Hopkins University
PSP/FIELDS data release 5.1, on October 19, 2020, updates the dfb_dbm_scm and dfb_wf_dvdc data types to version 3. The new data versions contain significant corrections to the previously released data.
PSP/FIELDS data release 7, on April 4, 2021, includes data from PSP Encounter 6 (September 2020). All data up to and including December 2020 are now publicly available. For this data release, all DFB cross spectra have been reprocessed (with a new version number), and a subset of MAG data has also been reprocessed (with a new version number).
PSP/FIELDS data release 8, on June 28, 2021, includes survey data from PSP Encounter 7 and Venus Gravity assist 4. Several data sets have been updated in release 8.
PSP/FIELDS Data Release 9, on October 29, 2021, includes select data from Encounter 7 (perihelion January 2021), and survey and select data from Encounter 8 (perihelion April 2021).
PSP/FIELDS Data Release 10, on February 7, 2022, includes survey and select data from Encounter 9 (perihelion August 2021).
PSP/FIELDS Data Release 11, on April 25, 2022, includes survey and select data from Encounter 10 (perihelion November 2021), and survey and select data from Venus Gravity Assist 5 (October 2021).
Access to Data in CDF Format via ftp from SPDF
Access to Data in CDF Format via http from SPDF
Access to ASCII, CDF, and Plots via NASA/GSFC CDAWeb
Web Service to this product using the HAPI interface.
Epoch Time Tags in Terrestrial Time 2000, TT2000, for Digital Fields Board, DFB, DC-coupled SCMdlfhg-SCMflfhg Cross Spectra
FIELDS Digital Fields Board, DFB, Frequency Bins for DC-coupled SCMdlfhg-SCMflfhg Cross Spectra
Auto Spectra, Power, channel SCMflfhg
Saturation Flags for Auto Spectra, Power, channel SCMdlfhg
Auto Spectra, Power, channel SCMflfhg
Saturation Flags for Auto Spectra, Power, channel SCMflfhg
Cross Spectra, Coherence between channels SCMdlfhg-SCMflfhg
Saturation Flags for Cross Spectra, Coherence between channels SCMdlfhg-SCMflfhg
Cross Spectra, Phase of channel SCMflfhg relative to channel SCMdlfhg
Saturation Flags for Cross Spectra, Phase of channel SCMflfhg relative to channel SCMdlfhg
Cross Spectra, Real Part (co-spectra) of the Fourier Transfrom cross term (FT₁ ⨯ FT₂*), channels SCMdlfhg-SCMflfhg
Saturation Flags for Cross Spectra, Real Part of the Fourier Transfrom cross term (FT₁ ⨯ FT₂*), channels SCMdlfhg-SCMflfhg
Cross Spectra, Imaginary Part (quadrature) of the Fourier Transfrom cross term (FT₁ ⨯ FT₂*), channels SCMdlfhg-SCMflfhg
Saturation Flags for Cross Spectra, Imaginary Part of the Fourier Transfrom cross term, channels SCMdlfhg-SCMflfhg
Epoch Time Tags in Terrestrial Time 2000, TT2000, for FIELDS Instrument Suite Data Quality Flags
FIELDS Instrument Suite Data Quality Flags
Rotation Matrix from (d,e,f) to (u,v,w) Coordinates