2.5.0
spase://NASA/NumericalData/MMS/2/FIELDS/EDI/Survey/Level2/QualityZero/PT0.125S
MMS 2 Electron Drift Instrument (EDI) Quality Zero Counts, Level 2 (L2), Survey Mode, 0.125 s Data
MMS2_EDI_SRVY_L2_Q0
https://doi.org/10.48322/ydzg-zr55
2023-03-04T12:34:56.789
2021-04-27T15:38:11
Only known prior ReleaseDate of the metadata
2022-08-04T12:34:56.789
Added DOI and PublicationInfo minted by LFB, updated the RepositoryID, updated the SPDF MetadataContact Person to Robert M. Candey, metadata updated to SPASE 2.4.1, reviewed by LFB 20220803
2023-03-04T12:34:56.789
Standardized the ResourceName Format, Set AlternateName equal to the ProductKey, Revised the Acknowledgement, PublicationInfo Authors, and Contact Person list per request of the MMS EDI team, metadata updated to SPASE 2.5.0, reviewed by LFB 20230304
Electron Drift Instrument (EDI) Q0 Survey, Level 2, 0.125 s Data (8 samples/s). EDI has two scientific data acquisition modes, called electric field mode and ambient mode. In electric field mode, two coded electron beams are emitted such that they return to the detectors after one or more gyrations in the ambient magnetic and electric field. The firing directions and times-of-flight allow the derivation of the drift velocity and electric field. In ambient mode, the electron beams are not used. The detectors with their large geometric factors and their ability to adjust the field of view quickly allow continuous sampling of ambient electrons at a selected pitch angle and fixed but selectable energy. To find the beam directions that will hit the detector, EDI sweeps each beam in the plane perpendicular to B at a fixed angular rate of 0.22 °/ms until a signal has been acquired by the detector. Once signal has been acquired, the beams are swept back and forth to stay on target. Beam detection is not determined from the changes in the count-rates directly, but from the square of the beam counts divided by the background counts from ambient electrons, i.e., from the square of the instantaneous signal-to-noise ratio (SNR). This quantity is computed from data provided by the correlator in the Gun-Detector Electronics that also generates the coding pattern imposed on the outgoing beams. If the squared SNR ratio exceeds a threshold, this is taken as evidence that the beam is returning to the detector. The thresholds for SNR are chosen dependent on background fluxes. They represent a compromise between getting false hits (induced by strong variations in background electron fluxes) and missing true beam hits. The basic software loop that controls EDI operations is executed every 2 ms. As the times when the beams hit their detectors are neither synchronized with the telemetry nor equidistant, EDI data have no fixed time-resolution. Data are reported in telemetry slots. In Survey, using the standard packing mode 0, there are eight telemetry slots per second and Gyn Detector Unit (GDU). The last beam detected during the previous slot will be reported in the current slot. If no beam has been detected, the data quality will be set to zero. In Burst telemetry there are 128 slots per second and GDU. The data in each slot consists of information regarding the beam firing directions (stored in the form of analytic gun deflection voltages), times-of-flight (if successfully measured), quality indicators, time stamps of the beam hits, and some auxiliary correlator-related information. Whenever EDI is not in electron drift mode, it uses its ambient electron mode. The mode has the capability to sample at either 90 degrees pitch angle or at 0/180 degrees (field aligned), or to alternate between 90 degrees and field aligned with selectable dwell times. While all options have been demonstrated during the commissioning phase, only the field aligned mode has been used in the routine operations phase. The choices for energy are 250 eV, 500 eV, and 1 keV. The two detectors, which are facing opposite hemispheres, are looking strictly into opposite directions, so while one detector is looking along B the other is looking antiparallel to B (corresponding to pitch angles of 180 and 0 degrees, respectively). The two detectors switch roles every half spin of the spacecraft as the tip of the magnetic field vector spins outside the field of view of one detector and into the field of view of the other detector. These data are a by-product generated from data collected in electric field mode. Whenever no return beam is found in a particular time slot by the flight software to be reported will be flagged with the lowest quality level (quality zero). The ground processing generates a separate data product from these counts data. The EDI instrument paper can be found at: http://link.springer.com/article/10.1007%2Fs11214-015-0182-7. The EDI instrument data products guide can be found at https://lasp.colorado.edu/mms/sdc/public/datasets/fields/.
Please acknowledge R.B. Torbert, M.R. Argall, and J.L. Burch for use of these data
Torbert, Roy, B.; Argall, Matthew, R.; Burch, James, L.
2022-01-01T00:00:00
NASA Space Physics Data Facility
spase://SMWG/Person/Roy.B.Torbert
InstrumentLead
CoInvestigator
spase://SMWG/Person/Matthew.R.Argall
Developer
GroundSoftwareDeveloper
spase://SMWG/Person/James.L.Burch
PrincipalInvestigator
spase://SMWG/Person/MMS_SDC_POC
HostContact
spase://SMWG/Person/Robert.M.Candey
MetadataContact
spase://SMWG/Person/Lee.Frost.Bargatze
MetadataContact
The Magnetospheric Multiscale (MMS) Mission home page at Goddard Space Flight Center (GSFC)
https://mms.gsfc.nasa.gov/
The Magnetospheric Multiscale (MMS) Mission Home Page hosted by the Goddard Space Flight Center (GSFC).
Data Caveats and Current Release Notes at LASP MMS SDC
https://lasp.colorado.edu/mms/sdc/public/datasets/fields/
The Magnetospheric Multiscale (MMS) Mission home page hosted by the Laboratory of Atmospheric and Space Physics, Science Data Center (LASP, SDC) at the University of Colorado, Boulder.
At UNH
https://mms-fields.unh.edu/
The Magnetospheric Multiscale (MMS) FIELDS Instrument Suite home page. The web page is hosted by the University of New Hampshire (UNH).
spase://VSPO/NumericalData/MMS/2/FIELDS/EDI/Survey/Level2/QualityZero/PT0.125S
spase://SMWG/Repository/UCOLO/LASP/MMS_SDC
Online
Open
FTPS from the MMS SDC (not with most browsers)
ftps://lasp.colorado.edu/mms/sdc/public/data/mms2/edi/srvy/l2/q0/
In CDF via ftp from the MMS Science Data Center
HTTPS from the MMS SDC
https://lasp.colorado.edu/mms/sdc/public/data/mms2/edi/srvy/l2/q0/
In CDF via http from the MMS Science Data Center
CDF
None
Please acknowledge R.B. Torbert, M.R. Argall, and J.L. Burch. Also please acknowledge the data providers and CDAWeb when using these data.
spase://SMWG/Repository/NASA/GSFC/SPDF/CDAWeb
Online
Open
FTPS from SPDF (not with most browsers)
ftps://spdf.gsfc.nasa.gov/pub/data/mms/mms2/edi/srvy/l2/q0/
In CDF via ftp from SPDF
HTTPS from SPDF
https://spdf.gsfc.nasa.gov/pub/data/mms/mms2/edi/srvy/l2/q0/
In CDF via http from SPDF
CDAWeb
https://cdaweb.gsfc.nasa.gov/cgi-bin/eval2.cgi?dataset=MMS2_EDI_SRVY_L2_Q0&index=sp_phys
MMS2_EDI_SRVY_L2_Q0
Access to ASCII, CDF, and plots via NASA/GSFC CDAWeb
CDF
None
Please acknowledge R.B. Torbert, M.R. Argall, and J.L. Burch. Also please acknowledge the data providers and CDAWeb when using these data.
spase://SMWG/Repository/NASA/GSFC/SPDF/CDAWeb
Online
Open
CDAWeb HAPI Server
https://cdaweb.gsfc.nasa.gov/hapi
MMS2_EDI_SRVY_L2_Q0
Web Service to this product using the HAPI interface
CSV
Please acknowledge R.B. Torbert, M.R. Argall, and J.L. Burch. Also please acknowledge the data providers and CDAWeb when using these data.
Calibrated
spase://SMWG/Instrument/MMS/2/FIELDS/EDI
EnergeticParticles
2015-04-21T00:00:00.000
-P2M
PT0.125S
Earth.Magnetosheath
Earth.Magnetosphere
Earth.Magnetosphere.Magnetotail
Earth.Magnetosphere.Main
Earth.Magnetosphere.RadiationBelt
Earth.NearSurface.EquatorialRegion
Earth.NearSurface.Plasmasphere
Heliosphere.NearEarth
Epoch Time, Quality 0 GDU2 Counts
epoch_gd12
Epoch Time Tags for Quality 0 Gun Detector Unit 2 Count Data, Terrestrial Time 2000 (TT2000)
PT0.125S
ns
1e-9>s
UT
I16
2015-03-01T00:00:00.000000000
2050-03-01T00:00:01.000000000
9999-12-31T23:59:59.999999999
Temporal
Epoch Time, Quality 0 GDU1 Counts
epoch_gd21
Epoch Time Tags for Quality 0 Gun Detector Unit 1 Count Data, Terrestrial Time 2000 (TT2000)
PT0.125S
ns
1e-9>s
UT
I16
2015-03-01T00:00:00.000000000
2050-03-01T00:00:01.000000000
9999-12-31T23:59:59.999999999
Temporal
GDU1 Beam Energy
Time series defined by using: EPOCH_GD12
mms2_edi_energy_gd12
Gun Detector Unit 2 Beam Energy
PT0.125S
eV
1.602e-19>J
TimeSeries
Energy
I5
0
1000
65535
Electron
Scalar
Energy
GDU2 Beam Energy
Time series defined by using: EPOCH_GD21
mms2_edi_energy_gd21
Gun Detector Unit 1 Beam Energy
PT0.125S
eV
1.602e-19>J
TimeSeries
Energy
I5
0
1000
65535
Electron
Scalar
Energy
Quality 0 Counts GDU2
Time series defined by using: EPOCH_GD12
mms2_edi_counts_gd12
Gun Detector Unit 2 Quality 0 Counts
PT0.125S
TimeSeries
Q0 Counts
I5
0
65534
65535
Electron
Scalar
Counts
Quality 0 Counts GDU1
Time series defined by using: EPOCH_GD21
mms2_edi_counts_gd21
Gun Detector Unit 1 Quality 0 Counts
PT0.125S
TimeSeries
Q0 Counts
I5
0
65534
65535
Electron
Scalar
Counts