Data

All PSP/FIELDS Level 2 and higher data are open to all scientists and the general public.  FIELDS data products are available in NASA CDF format.  All interested users should read the Rules of the Road for use of FIELDS data.

Data release history

  1. The initial data release on 2019 November 12 includes data from the first two PSP solar encounters, which had their perihelions on 2018 November 6 and 2019 April 4, respectively.  

Data Description

All data products are available at the following link:

http://research.ssl.berkeley.edu/data/psp/data/sci/fields/l2/

Data products included in the initial release are described below.  Each data type corresponds to a directory in the Level 2 URL above.  Additional data products that will be released in the near future are also listed, along with their anticipated release date.

Data from the FIELDS Digital Fields Board (DFB).  These data include bandpass filter, spectra, and waveform data from the electric field antennas and the search coil magnetometer.  Data are available in daily files, except for the survey waveform files, which are split into four six-hour intervals per day. Coordinate systems used vary by DFB data product.  Please consult the TEXT metadata field in each CDF for the coordinate system used and an explanation for the choice of coordinate system.  

A full description of the available DFB data is provided in the global metadata in each CDF file, and in the DFB instrument paper

  • dfb_ac_bpf
  • dfb_ac_spec
  • dfb_dc_bpf
  • dfb_dc_spec
  • dfb_wf_dvdc
  • dfb_wf_scm
  • dfb_wf_vdc

DFB data to be released soon after the initial data release include burst waveforms (dbm) and cross spectra (xspec).  

  • dfb_dbm (initial data release +3 weeks)
  • dfb_ac_xspec (initial data release +3 weeks)
  • dfb_dc_xspec (initial data release +3 weeks)

Science summary (100 bps) data from the FIELDS2 (TDS) instrument.

  • f2_100bps

TDS data to be released soon after the initial data release include burst waveforms (tds_wf).  

  • tds_wf (initial data release +4 weeks)

DC Magnetic field data from the fluxgate magnetometer (MAG).  The MAG data are available in spacecraft coordinates (SC:, x,y,z) as well as radial-tangential-normal (RTN) coordinates.  The data are available at several time resolutions: full cadence (no suffix past SC/RTN), downsampled to 1 minute (_1min), and downsampled to 4 samples per cycle (_4_Sa_per_Cyc, approximately 4.58 samples/second).  Full cadence files are split into four six-hour intervals per day.

  • mag_RTN
  • mag_RTN_1min
  • mag_RTN_4_Sa_per_Cyc
  • mag_SC
  • mag_SC_1min
  • mag_SC_4_Sa_per_Cyc

Data from the Radio Frequency Receiver (RFS) High Frequency Receiver (HFR) and Low Frequency Receiver (LFR).  HFR primarily measures remote radio emission from the Sun, Jupiter, and the galaxy, while LFR measures radio emission as well as quasi-thermal noise and plasma waves.  For a full description of the RFS data, see the RFS instrument paper.  

  • rfs_hfr
  • rfs_lfr

Data Access

For users of SPEDAS (http://spedas.org/), a basic load routine exists (in the bleeding edge version of SPEDAS available here) which will load each of the data sets above.  We are working on adding a more fully-featured and documented set of load and plot routines.  A simple example is shown below, and the type keyword can be changed to any of the above data types.

timespan, '2019-04-04'
psp_fld_load, type = 'mag_RTN_4_Sa_per_Cyc'

The FIELDS CDF data files include ISTP-compliant metadata, so they should also be compatible with CDF-compatible software such as Autoplot and MATLAB, or in Python using the cdflib library.

Additional information on accessing and plotting FIELDS data will be available soon on this page.

Quality flags

FIELDS L2 files (with the exception of the f2_100bps file) include a set of quality flags.

Quality flags are on a 1 minute cadence, identifying intervals where instrument or spacecraft activities can affect the measurements.  0 signifies the absence of any flags. The individual flags are identified in the CDF metadata as follows:

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 (heat shield not pointed sunward). 
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.

SCM Anomaly

Starting in early March 2019, there was an abrupt change in the response of one axis of the search coil magnetometer (the low frequency winding of the u axis).  The SCM team is work to determine the source of the anomaly. Although it may be possible to compensate for the changed response (at some frequencies), much of the existing data from this SCM axis for Encounter 2 is not a scientifically useful data set.

This affects the DFB SCM waveform, bandpass filter, and spectral data in different ways.

  • The SCM waveform files for Encounter 1 contain sensor (u,v,w) and spacecraft (x,y,z) coordinates.  The u axis is the axis which has corrupted data, so it is removed from the SCM waveform for Encounter 2.  The spacecraft coordinates are produced from the sensor coordinates by a rotation matrix–and unfortunately, rotating one bad component into a different system produces three bad components.  So, in the Encounter 2 L2 SCM waveform CDF files, the u sensor axis and all three of the spacecraft x,y,z axes are set to fill values.
  • One of the two DC bandpass filter data sets uses the SCM u axis as an input during Encounter 2.  These files are affected by the SCM anomaly and are not included in the public data release.
  • The spectra for Encounters 1 and 2 are rotated into a third coordinate system, the (d,e,f) coordinate system.  The rotation matrix describing (d,e,f) is included in the spectra files as metadata.  The (d,e,f) spectra files have not been uploaded to the public data folder for Encounter 2, since they are affected by the anomalous SCM u axis data. 

Finally, we note that the affected SCM u axis has two coils, one for low frequencies (LF: ~10 Hz to ~25 kHz) and one for medium frequencies (MF: ~1 kHz to ~1 MHz).  The MF winding is not affected by the anomaly. When the source of the DFB bandpass filter or spectra data is the MF coil, the data are unaffected and have been included in the released data set.

Acknowledgements

Parker Solar Probe was designed, built, and is now operated by the Johns Hopkins Applied Physics Laboratory as part of NASA’s Living with a Star (LWS) program (contract NNN06AA01C). Support from the LWS management and technical team has played a critical role in the success of the Parker Solar Probe mission.