PARKER SOLAR PROBE FIELDS Level 2 DFB Search Coil Magnetometer (SCM) Waveform (CDF)

https://doi.org/10.24400/802406/m5h0-wfvq

2022-07-04 15:46:59Z

This data set contains the PARKER SOLAR PROBE FIELDS Level 2 Search-coil (SCM) waveform data from the low-frequency (LF) antennas.
The waveforms consist of 3 components of the magnetic field, expressed in sensor coordinates (Bu, Bv, Bw) and in spacecraft coordinates (Bx, By, Bz). For the description of the coordinate systems, see the description of the SCM. Time (epoch) is in TT2000 format and corresponds to nanoseconds since 1 Jan 2000 12:00:00 with leap seconds included.
The SCM operates mostly during encounter phases (i.e. during a period of typically two weeks around each perihelion). The time resolution for the waveforms is 150000 Hz / 2^N. In general, N=9, which corresponds to 292.969 samples per second. During encounters 6 and 7 the sampling rate occasionally went as high as 2343.8 Hz. The LF antennas of the SCM have a low-frequency cutoff at 3 Hz and an upper frequency rolloff at 10 kHz. Waveforms therefore should not be interpreted below 3 Hz.
The waveforms of the Search-Coil Magnetometer (SCM) [Jannet et al., 2021] are primarily registered by the Digital Fields Board (DFB) instrument [Malaspina et al., 2016], which is part of the FIELDS suite [Bale et al., 2016]. DFB provides waveform data for various FIELDS sensors.
The Level 2 data products are calibrated for :

• DFB in-band gain,
• DFB analog filter gain/phase response,
• DFB digital filter phase (not gain) response, and the search coil preamplifier gain/phase response (when applicable).
  Calibrations for the DFB digital filter gain response have not been implemented, but the required convolution kernel is provided in the cdf datafiles. The reason for not including this gain response in the L2 data is because this can introduce unphysical enhancements of spectral power at high frequencies when the uncorrected signal is dominated by noise. This effect should be examined carefully when determining spectral slopes and features at the highest frequencies. All magnetic fields are expressed in nT.
  Calculation of the PSP-Sun distance for the selection criterion (see Filter tab) is realized each day at 00:00.
  SCM anomaly:
  From 3 March 2019 onwards the LF Bu antenna lost its sensitivity below 1 kHz. This problem occurs whenever the sensor is cold, i.e. at perihelion. At the same time, the sensitivity of the LF Bu antenna to periodic spikes associated with heater cycling has increased by two orders of magnitude. The data are correct for encounter 1 (October-November 2018) only. For subsequent encounters, only Bv and Bw should be used, or Bu above 1 kHz.

References:
FIELDS website: https://fields.ssl.berkeley.edu/
Bale, S. 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, Volume 204, Issue 1-4, pp.49-82, doi:10.1007/s11214-016-0244-5
Malaspina, D.M., Ergun, R.E., Bolton, M. et al. (2016), The Digital Fields Board for the FIELDS instrument suite on the Solar Probe Plus mission: Analog and digital signal processing, Journal of Geophysical Research: Space Physics, 121, 5088-5096, doi: 10.1002/2016JA022344
Jannet, G., Dudok de Wit, T., Krasnoselskikh, V. et al. (2021), Measurement of magnetic field fluctuations in the parker solar probe and solar orbiter missions, Journal of Geophysical Research: Space Physics, 126, e2020JA028543 doi: 10.1029/2020JA028543

Please add the following to your acknowledgements when using SCM data: The authors acknowledge CNES (Centre National d'Etudes Spatiales), NASA and CNRS (Centre National de la Recherche Scientifique) for their support to the PSP/SCM team, and the CDPP (Centre de Données de la Physique des Plasmas) for the distribution of the PSP/SCM data. The FIELDS experiment on the PSP spacecraft was designed and developed under NASA contract NNN06AA01C. Other datasets from FIELDS can be found at https://fields.ssl.berkeley.edu/ . For other instruments of Parker Solar Probe, see https://cdaweb.gsfc.nasa.gov/index.html/ Please cite the following reference papers when using SCM data: G. Jannet, T. Dudok de Wit, V. Krasnoselskikh, M. Kretzschmar, P. Fergeau, M. Bergerard-Timofeeva, C. Agrapart, J.-Y. Brochot, G. Chalumeau, P. Martin, C. Revillet, S. D. Bale, M. Maksimovic, T. A. Bowen, C. Brysbaert, K. Goetz, E. Guilhem, P. R. Harvey, V. Leray, and E. Lorfèvre, Measurement of magnetic field fluctuations in the Parker Solar Probe and solar orbiter missions, Journal of Geophysical Research: Space Physics, 126 (2021), e2020JA028543, doi:10.1029/2020JA028543 [NASA ADS: https://ui.adsabs.harvard.edu/abs/2021JGRA..12628543J]

Online

CDF

Magnetic field from SCM High Gain in Sensor coordinates (uvw)

L2 Magnetic field from SCM High Gain in Sensor coordinates

nT

1e-9>T

Magnetic field from SCM High Gain in SC coordinates

L2 Magnetic field from SCM High Gain in spacecraft coordinates

nT

1e-9>T

Noise floor for High Gain SCM channels

Noise floor for High Gain SCM channels B_U, B_V, B_W

nT/Hz^1/2

1e-9>T/Hz^1/2

Magnetic field from SCM Low Gain in Sensor coordinates

L2 Magnetic field from SCM Low Gain in Sensor coordinates (uvw)

nT

1e-9>T

Magnetic field from SCM Low Gain in spacecraft coordinates

L2 Magnetic field from SCM Low Gain in spacecraft coordinates

nT

1e-9>T

Noise floor for Low Gain SCM channels

Noise floor for Low Gain SCM channels B_U, B_V, B_W

nT/Hz^1/2

1e-9>T/Hz^1/2

Kernel (real part) needed to correct for digital filter response (293 Hz)

Kernel (real part) needed to correct for digital filter response (293 Hz)

Kernel (imaginary part) needed to correct for digital filter response (293 Hz)

Kernel (imaginary part) needed to correct for digital filter response (293 Hz)

Kernel (real part) needed to correct for digital filter response (146 Hz)

Kernel (real part) needed to correct for digital filter response (146 Hz)

Kernel (imaginary part) needed to correct for digital filter response (146 Hz)

Kernel (imaginary part) needed to correct for digital filter response (146 Hz)

Kernel (real part) needed to correct for digital filter response (73 Hz)

Kernel (real part) needed to correct for digital filter response (73 Hz)

Kernel (imaginary part) needed to correct for digital filter response (73 Hz)

Kernel (imaginary part) needed to correct for digital filter response (73 Hz)

Kernel (real part) needed to correct for digital filter response (37 Hz)

Kernel (real part) needed to correct for digital filter response (37 Hz)

Kernel (imaginary part) needed to correct for digital filter response (37 Hz)

Kernel (imaginary part) needed to correct for digital filter response (37 Hz)

Kernel (real part) needed to correct for digital filter response (18 Hz)

Kernel (real part) needed to correct for digital filter response (18 Hz)

Kernel (imaginary part) needed to correct for digital filter response (18 Hz)

Kernel (imaginary part) needed to correct for digital filter response (18 Hz)

Kernel (real part) needed to correct for digital filter response (9 Hz)

Kernel (real part) needed to correct for digital filter response (9 Hz)

Kernel (imaginary part) needed to correct for digital filter response (9 Hz)

Kernel (imaginary part) needed to correct for digital filter response (9 Hz)

Kernel (real part) needed to correct for digital filter response (5 Hz)

Kernel (real part) needed to correct for digital filter response (5 Hz)

Kernel (imaginary part) needed to correct for digital filter response (5 Hz)

Kernel (imaginary part) needed to correct for digital filter response (5 Hz)

Kernel (real part) needed to correct for digital filter response (2 Hz)

Kernel (real part) needed to correct for digital filter response (2 Hz)

Kernel (imaginary part) needed to correct for digital filter response (2 Hz)

Kernel (imaginary part) needed to correct for digital filter response (2 Hz)

FIELDS quality flag

FIELDS quality flags. This is a bitwise variable, meaning that multiple flags can be set for a single time, by adding flag values. Current flagged values are: 1: FIELDS antenna bias sweep, 2: PSP thruster firing, 4: SCM Calibration, 8: PSP rotations for MAG calibration (MAG rolls), 16: FIELDS MAG calibration sequence, 32: SWEAP SPC in electron mode, 64: PSP Solar limb sensor (SLS) test. 128: PSP spacecraft is off umbra pointing. A value of zero corresponds to no set flags. Not all flags are relevant to all FIELDS data products, refer to notes in the CDF metadata and on the FIELDS SOC website for information on how the various flags impact FIELDS data. Additional flagged items may be added in the future.