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LANL 2001 Magnetospheric Plasma Analyzer (MPA) at 87 sec Resolution in Spacecraft Coordinates

(2023). LANL 2001 Magnetospheric Plasma Analyzer (MPA) at 87 sec Resolution in Spacecraft Coordinates [Data set]. NASA Space Physics Data Facility. https://doi.org/10.48322/6jar-ra45. Accessed on .
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ResourceID
spase://NASA/NumericalData/LANL/2001/MPA/PT87S

Description

The LANL 01A MPA data set contains numerical moments computed from measurements of the Los Alamos Magnetospheric Plasma Analyzer (MPA) [Bame et al., Rev. Sci. Inst., in press 1993]. The moments are presented in s/c coordinates: the z-axis is aligned with the spin axis, which points radially toward the center of the Earth; the x-axis is in the plane containing the spacecraft spin axis and the spin axis of the Earth, with +X generally northward; and the y-axis points generally eastward. Polar angles are measured relative to the spin axis (+Z), and azimuthal angles are measured around the z-axis, with zero along the +X direction. The moments are computed for three 'species': lop (low-ener. ions, ~1eV/e-~130eV/e); hip (hi-ener. ions, ~130eV/e-~45keV/e); alle (electrons, ~30eV - ~45keV ). The electron measurements are obtained 21.5 secs after the ion measurements. Epoch is the measurement time appropriate for the ions. The moments are computed after the fluxes are corrected for background and s/c potential. Algorithms for these corrections are relatively unsophisticated, so the moments are suspect during times of high background and/or high spacecraft potential. Because the determined spacecraft potential is not very precise, the magnitude of the low-energy ion flow velocity is probably not accurate, but the flow direction is well determined. Tperp and Tpara are obtained from diagonalization of the 3-dimensional temperature matrix, with the parallel direction assigned to the eigenvalue which is most different from the other two. The corresponding eigenvector is the symmetry axis of the distribution and should be equivalent to the magnetic field direction. The eigenvalue ratio Tperp/Tmid, which is provided for each species, is a measure of the symmetry of the distribution and should be ~1.0 for a good determination. Several of the parameters have a fairly high daily dynamic range and for survey purposes are best displayed logarithmically. These parameters are indicated by non-zero 'SCALEMIN' values in this file. A quality flag value of 1 indicates that the values are suspect because of unreliable location info.

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Details

Version:2.6.0

NumericalData

ResourceID
spase://NASA/NumericalData/LANL/2001/MPA/PT87S
ResourceHeader
ResourceName
LANL 2001 Magnetospheric Plasma Analyzer (MPA) at 87 sec Resolution in Spacecraft Coordinates
AlternateName
LANL 01A MPA data
DOI
https://doi.org/10.48322/6jar-ra45
ReleaseDate
2023-12-24 12:34:56.789
RevisionHistory
RevisionEvent
ReleaseDate
2021-04-27 15:38:11
Note
Only known prior ReleaseDate of the metadata
RevisionEvent
ReleaseDate
2023-07-30 12:34:56.789
Note
Added DOI and PublicationInfo minted by LFB, metadata versioned up to SPASE 2.6.0, reviewed by LFB 20230727
RevisionEvent
ReleaseDate
2023-12-24 12:34:56.789
Note
Correct geosynchronous spelling as requested. Removed ftp link. Corrected CDAWeb url. JMW
Description

The LANL 01A MPA data set contains numerical moments computed from measurements of the Los Alamos Magnetospheric Plasma Analyzer (MPA) [Bame et al., Rev. Sci. Inst., in press 1993]. The moments are presented in s/c coordinates: the z-axis is aligned with the spin axis, which points radially toward the center of the Earth; the x-axis is in the plane containing the spacecraft spin axis and the spin axis of the Earth, with +X generally northward; and the y-axis points generally eastward. Polar angles are measured relative to the spin axis (+Z), and azimuthal angles are measured around the z-axis, with zero along the +X direction. The moments are computed for three 'species': lop (low-ener. ions, ~1eV/e-~130eV/e); hip (hi-ener. ions, ~130eV/e-~45keV/e); alle (electrons, ~30eV - ~45keV ). The electron measurements are obtained 21.5 secs after the ion measurements. Epoch is the measurement time appropriate for the ions. The moments are computed after the fluxes are corrected for background and s/c potential. Algorithms for these corrections are relatively unsophisticated, so the moments are suspect during times of high background and/or high spacecraft potential. Because the determined spacecraft potential is not very precise, the magnitude of the low-energy ion flow velocity is probably not accurate, but the flow direction is well determined. Tperp and Tpara are obtained from diagonalization of the 3-dimensional temperature matrix, with the parallel direction assigned to the eigenvalue which is most different from the other two. The corresponding eigenvector is the symmetry axis of the distribution and should be equivalent to the magnetic field direction. The eigenvalue ratio Tperp/Tmid, which is provided for each species, is a measure of the symmetry of the distribution and should be ~1.0 for a good determination. Several of the parameters have a fairly high daily dynamic range and for survey purposes are best displayed logarithmically. These parameters are indicated by non-zero 'SCALEMIN' values in this file. A quality flag value of 1 indicates that the values are suspect because of unreliable location info.

Acknowledgement
Los Alamos National Laboratory; Dr. Michelle Thomsen; Dr. Michael G. Henderson
PublicationInfo
Authors
Thomsen, Michelle, F.; Henderson, Michael, G.
PublicationDate
2023-01-01 00:00:00
PublishedBy
NASA Space Physics Data Facility
Contacts
RolePersonStartDateStopDateNote
1.PrincipalInvestigatorspase://SMWG/Person/Michelle.F.Thomsen
2.GeneralContactspase://SMWG/Person/Michael.G.Henderson
3.MetadataContactspase://SMWG/Person/James.M.Weygand
4.MetadataContactspase://SMWG/Person/Lee.Frost.Bargatze
InformationURL
Name
Los Alamos National Laboratory Spacecraft Magnetospheric Plasma Analyzer
URL
Description

Journal of Geophysical Research article on the LANL MPA instrument.

PriorIDs
spase://VMO/NumericalData/LANL/LANL2001/MPA/PT87S
spase://VMO/NumericalData/LANL/2001/MPA/PT87S
spase://VSPO/NumericalData/LANL/2001/MPA/PT87S
AccessInformation
RepositoryID
Availability
Online
AccessRights
Open
AccessURL
Name
HTTPS from SPDF
URL
Description

In CDF via HTTP from SPDF

AccessURL
Name
CDAWeb
URL
ProductKey
A1_K0_MPA
Description

subset, plot, and ASCII list from CDAWeb.

Format
CDF
Acknowledgement
LANL; Dr. Michelle Thomsen; Dr. Michael G. Henderson
AccessInformation
RepositoryID
Availability
Online
AccessRights
Open
AccessURL
Name
CDAWeb HAPI Server
URL
Style
HAPI
ProductKey
A1_K0_MPA
Description

Web Service to this product using the HAPI interface.

Format
CSV
Acknowledgement
LANL; Dr. Michelle Thomsen; Dr. Michael G. Henderson
ProcessingLevel
Calibrated
ProviderResourceName
LANL 01A MPA
ProviderProcessingLevel
Numerical Data
InstrumentIDs
MeasurementType
EnergeticParticles
TemporalDescription
TimeSpan
StartDate
2001-08-31 00:00:00
StopDate
2008-01-03 23:59:59
Note
Time format in data files is: day, month, year hour, min, seconds. Ex: '01-Jan-1981 00:00:00.000'
Cadence
PT87S
Caveats
Flags=-1.0e+31. The content of the LANL SOPA cdfs at CDAWeb has not been fully documented.
Keywords
87 sec
Geosynchronous
LANL
Magnetospheric Plasma Analyzer
MPA
Parameter #1
Name
LANL 01A MPA Time of proton collection
ParameterKey
Epoch
Description

This is the time of the proton data collection (electrons 21.5 seconds later). Universal Time in data cell: day, month, year hour, min, seconds. Ex: '01-Jan-1981 00:00:00.000'.

Caveats
Interval centered time tag
Units
ms
UnitsConversion
'1.0e-3>s'
RenderingHints
AxisLabel
Epoch
ValidMin
01-08-1992T00:00:00.000
ValidMax
31-12-2020T23:59:59.000
FillValue
-1.0000e+031
Support
SupportQuantity
Temporal
Parameter #2
Name
LANL 01A MPA Time of proton collection
ParameterKey
Time_PB5
Description

This is the time of the proton collection (electrons 21.5 seconds later). Time in the format: year, day of year, and second of the same day.

Caveats
Interval centered time tag
RenderingHints
AxisLabel
Epoch
Structure
Size
3
Description

Date and Time Vector.

Element
Name
Year
Index
1
Units
Years
ValidMin
1992
ValidMax
2020
Element
Name
Day of Year
Index
2
Units
Days
ValidMin
0
ValidMax
366
Element
Name
milliseconds of the day
Index
3
Units
ms
ValidMin
0
ValidMax
86399000
FillValue
-2147483648
Support
SupportQuantity
Temporal
Parameter #3
Name
LANL 01A MPA Partial Density of Low Energy Ions
ParameterKey
dens_lop
Description

Partial density of low energy ions (1-130 eV/e).

Units
cm^-3
UnitsConversion
1.0e6>m^-3
RenderingHints
AxisLabel
low p dens
ScaleMin
0.1
ScaleMax
1000.0
ValidMin
0.0
ValidMax
100000.0
FillValue
-1.0000e+031
Particle
ParticleType
Ion
Qualifier
Scalar
ParticleQuantity
NumberDensity
EnergyRange
Low
1
High
130
Units
eV/e
Parameter #4
Name
LANL 01A MPA Velocity Vector Low-Enery Ions
ParameterKey
vel_lop
Description

LANL 01A MPA velocity vector low-enery Ions (1-130 eV/e) in spacecraft Coordinates in units of km/s.

Units
km/s
UnitsConversion
1.0e3>m s^-1
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
SC
RenderingHints
ScaleMin
-100
ScaleMax
100
Structure
Size
3
Element
Name
VX
Qualifier
Component.I
Index
1
Element
Name
VY
Qualifier
Component.J
Index
2
Element
Name
VZ
Qualifier
Component.K
Index
3
ValidMin
-2000
ValidMax
2000
FillValue
-1.0000e+031
Particle
ParticleType
Ion
Qualifier
Vector
ParticleQuantity
Velocity
Parameter #5
Name
LANL 01A MPA Temperature Low Energy Ions
ParameterKey
temp_lop
Description

Temperature of low energy ions (1-130 eV/e).

Units
eV
RenderingHints
AxisLabel
low p temp
ScaleMin
0.1
ScaleMax
100.0
ValidMin
0.0
ValidMax
50000.0
FillValue
-1.0000e+031
Particle
ParticleType
Ion
Qualifier
Scalar
ParticleQuantity
Temperature
EnergyRange
Low
1
High
130
Units
eV/e
Parameter #6
Name
LANL 01A MPA Ratio of Temperature Eigenvalues for Low-E Ions
ParameterKey
tratio_lop
Description

Ratio of temperature (Tperp/Tmid) of low energy ions (1-130 eV/e).

RenderingHints
AxisLabel
Tper/Tmid
ScaleMin
0.1
ScaleMax
10.0
ValidMin
0.0
ValidMax
100.0
FillValue
-1.0000e+031
Particle
ParticleType
Ion
Qualifier
Ratio
ParticleQuantity
Temperature
EnergyRange
Low
1
High
130
Units
eV/e
Parameter #7
Name
LANL 01A MPA Partial Density High-E Ions
ParameterKey
dens_hip
Description

Spacecraft MPA partial density of high energy ions (.13-45 keV/e).

Units
cm^-3
RenderingHints
AxisLabel
hi p dens
ScaleMin
0.01
ScaleMax
10.0
ValidMin
0.0
ValidMax
10000.0
FillValue
-1.0000e+031
Particle
ParticleType
Ion
Qualifier
Scalar
ParticleQuantity
NumberDensity
EnergyRange
Low
0.13
High
45
Units
keV/e
Parameter #8
Name
LANL 01A MPA Velocity Vector High-E Ions
ParameterKey
vel_hip
Description

Velocity vector high-enery protons (.13-45 keV/e) in spacecraft Coordinates in units of km/s.

Units
km/s
UnitsConversion
1.0e3>m s^-1
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
SC
RenderingHints
ScaleMin
-200
ScaleMax
200
Structure
Size
3
Element
Name
VX
Qualifier
Component.I
Index
1
Element
Name
VY
Qualifier
Component.J
Index
2
Element
Name
VZ
Qualifier
Component.K
Index
3
ValidMin
-2000
ValidMax
2000
FillValue
-1.0000e+031
Particle
ParticleType
Ion
Qualifier
Vector
ParticleQuantity
Velocity
Parameter #9
Name
LANL 01A MPA Temperature High-E Ions
ParameterKey
temp_hip
Description

Spacecraft MPA temperature of high energy ions (.13-45 keV/e).

Units
eV
RenderingHints
AxisLabel
high p temp
ScaleMin
100
ScaleMax
100000.0
Structure
Size
2
Element
Name
Temp Parallel
Qualifier
Component.I
Index
1
Element
Name
Temp Perpendicular
Qualifier
Component.J
Index
2
ValidMin
0.0
ValidMax
50000.0
FillValue
-1.0000e+031
Particle
ParticleType
Ion
Qualifier
Array
ParticleQuantity
Temperature
EnergyRange
Low
0.13
High
45
Units
keV/e
Parameter #10
Name
LANL 01A MPA Polar, Azimuthal Angle High-E Proton Symmetry Axis
ParameterKey
theta_phi_hip
Description

Proton symmetry axis: polar angle relative to Earth direction, azimuthal angle from the north.

Units
deg
CoordinateSystem
CoordinateRepresentation
Spherical
CoordinateSystemName
SC
Structure
Size
2
Element
Name
Polar Angle
Qualifier
DirectionAngle.PolarAngle
Index
1
Units
degrees
ValidMin
0
ValidMax
180
Element
Name
Azimuthal Angle
Qualifier
DirectionAngle.AzimuthAngle
Index
2
Units
degrees
ValidMin
-90
ValidMax
90
FillValue
-1.0000e+031
Particle
ParticleType
Ion
Qualifier
Array
ParticleQuantity
ArrivalDirection
EnergyRange
Low
0.13
High
45
Units
keV/e
Parameter #11
Name
LANL 01A MPA Ratio of Temperature Eigenvalues for High-E Ions
ParameterKey
tratio_hip
Description

Ratio of temperature (Tperp/Tmid) of low energy ions (.13-45 keV/e).

RenderingHints
AxisLabel
Tper/Tmid
ScaleMin
0.1
ScaleMax
10.0
ValidMin
0.0
ValidMax
100.0
FillValue
-1.0000e+031
Particle
ParticleType
Ion
Qualifier
Ratio
ParticleQuantity
Temperature
EnergyRange
Low
0.13
High
45
Units
keV/e
Parameter #12
Name
LANL 01A MPA Partial Density Electrons
ParameterKey
dens_e
Description

Partial density of electrons (.03-45 keV/q).

Units
# cm^-3
RenderingHints
AxisLabel
elec dens
ScaleMin
0.01
ScaleMax
100.0
ValidMin
0.0
ValidMax
100000.0
FillValue
-1.0000e+031
Particle
ParticleType
Electron
Qualifier
Scalar
ParticleQuantity
NumberDensity
EnergyRange
Low
0.03
High
45
Units
keV/e
Parameter #13
Name
LANL 01A MPA Temperature Electrons
ParameterKey
temp_e
Description

Temperature of electrons (.03-45 keV/q).

Units
eV
RenderingHints
AxisLabel
Temperatures, parallel and perp. for electrons
ScaleMin
100
ScaleMax
100000.0
Structure
Size
2
Element
Name
Temp Parallel
Qualifier
Component.I
Index
1
Element
Name
Temp Perpendicular
Qualifier
Component.J
Index
2
ValidMin
0.0
ValidMax
50000.0
FillValue
-1.0000e+031
Particle
ParticleType
Electron
Qualifier
Array
ParticleQuantity
Temperature
EnergyRange
Low
0.03
High
45
Units
keV/e
Parameter #14
Name
LANL 01A MPA Polar, Azimuthal Angle Electron Symmetry Axis
ParameterKey
theta_phi_e
Description

Electron symmetry axis: polar angle relative to Earth direction, azimuthal angle from the north.

CoordinateSystem
CoordinateRepresentation
Spherical
CoordinateSystemName
SC
Structure
Size
2
Element
Name
Polar Angle
Qualifier
DirectionAngle.PolarAngle
Index
1
Units
degrees
ValidMin
0
ValidMax
180
Element
Name
Azimuthal Angle
Qualifier
DirectionAngle.AzimuthAngle
Index
2
Units
degrees
ValidMin
-90
ValidMax
90
FillValue
-1.0000e+031
Particle
ParticleType
Electron
Qualifier
Array
ParticleQuantity
ArrivalDirection
EnergyRange
Low
0.03
High
45
Units
keV/e
Parameter #15
Name
LANL 01A MPA Ratio of Temperature Eigenvalues for Electrons
ParameterKey
tratio_e
Description

Ratio of temperature (Tperp/Tmid) of electrons (.03-45 keV/q).

RenderingHints
AxisLabel
Tper/Tmid
ScaleMin
0.1
ScaleMax
10.0
ValidMin
0.0
ValidMax
100.0
FillValue
-1.0000e+031
Particle
ParticleType
Electron
Qualifier
Ratio
ParticleQuantity
Temperature
EnergyRange
Low
0.03
High
45
Units
keV/e
Parameter #16
Name
LANL 01A MPA Spacecraft Potential
ParameterKey
sc_pot
Description

Spacecraft potential in units of volts.

Units
volts
RenderingHints
AxisLabel
S/C poten.
ScaleMin
-10000.0
ScaleMax
0.0
ValidMin
-20000.
ValidMax
0.0
FillValue
-1.0000e+031
Field
Qualifier
Scalar
FieldQuantity
Potential
Parameter #17
Name
LANL 01A MPA Background Count Rate (Not Clear what this is the background for)
ParameterKey
bkgd
Description

Background Count Rate.

Units
cts/9ms
RenderingHints
AxisLabel
Backgrd
ScaleMin
0.1
ScaleMax
1000.0
ValidMin
0.0
ValidMax
1000.0
FillValue
-1.0000e+031
Support
Qualifier
Scalar
SupportQuantity
Other
Parameter #18
Name
LANL 01A MPA Spacecraft Position, Polar Geographic Coordinates
ParameterKey
sc_pos_geo
Description

Spacecraft position, polar geographic coordinates (radius,lat,long).

CoordinateSystem
CoordinateRepresentation
Spherical
CoordinateSystemName
GEO
Structure
Size
3
Description

Polar Geographic Coordinates.

Element
Name
Radius
Qualifier
Magnitude
Index
1
Units
EarthRadii
ValidMin
0
ValidMax
10
Element
Name
Latitude
Qualifier
DirectionAngle.ElevationAngle
Index
2
Units
degrees
ValidMin
-90
ValidMax
90
Element
Name
Longitude
Qualifier
DirectionAngle.AzimuthAngle
Index
3
Units
degrees
ValidMin
-180
ValidMax
180
FillValue
-1.0000e+031
Support
Qualifier
Vector
SupportQuantity
Positional
Parameter #19
Name
LANL 01A MPA Spacecraft Position, Cartesian Geocentric Celestial Inertial coordinates
ParameterKey
sc_pos_syngci
Description

Spacecraft position, cartesian coordinates (radius,lat,long). Geocentric Celestial Inertial, is earth centered, with the X-axis pointing from the Earth towards the first point of Aries (the position of the Sun at vernal equinox). This direction is the intersection of the Earth's equatorial plane and the ecliptic plane--thus the X-axis lies in both planes. The Z-axis is parallel to the rotation axis of the Earth, and the Y-axis completes a right-handed orthogonal coordinate system. The X-axis is the direction of the mean vernal equinox of J2000. This is a virtual variable generated by read_myCDF w/ useof the data in the sc_pos_geo variable and a conversion routinespecified in the function attribute, namely conv_pos.

CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GEI
Structure
Size
3
Description

Geocentric Celestial Inertial coordinates.

Element
Name
X
Qualifier
Component.I
Index
1
ValidMin
-1000
ValidMax
1000
Element
Name
Y
Qualifier
Component.J
Index
2
ValidMin
-1000
ValidMax
1000
Element
Name
Z
Qualifier
Component.K
Index
3
ValidMin
-1000
ValidMax
1000
FillValue
-1.0000e+031
Support
Qualifier
Vector
SupportQuantity
Positional
Parameter #20
Name
LANL 01A MPA Spacecraft Position, Polar Magnetic Coordinates
ParameterKey
sc_pos_mag
Description

Spacecraft position, polar magnetic coordinates (radius,lat,long).

CoordinateSystem
CoordinateRepresentation
Spherical
CoordinateSystemName
MAG
Structure
Size
3
Description

Polar Magnetic Coordinates.

Element
Name
Radius
Qualifier
Magnitude
Index
1
Units
EarthRadii
ValidMin
0
ValidMax
10
Element
Name
Latitude
Qualifier
DirectionAngle.ElevationAngle
Index
2
Units
degrees
ValidMin
-90
ValidMax
90
Element
Name
Magnetic Local Time
Qualifier
DirectionAngle.AzimuthAngle
Index
3
Units
hours
ValidMin
0
ValidMax
24
FillValue
-1.0000e+031
Support
Qualifier
Vector
SupportQuantity
Positional
Parameter #21
Name
LANL 01A MPA Data Quality Flag
ParameterKey
qual_flag
Description

Data quality flag. Data quality flag, 0 = ok, 1 = Results unreliable.

RenderingHints
AxisLabel
Qual Flag
ScaleMin
0.0
ScaleMax
10.0
ValidMin
0.0
ValidMax
10.0
FillValue
-2147483648
Support
Qualifier
Scalar
SupportQuantity
Other
Parameter #22
Name
LANL 01A MPA Data Gap Flag
ParameterKey
gap_flag
Description

Data gap flag. Data gap flag, 0 = No Gap, 10 = No data available.

RenderingHints
AxisLabel
Gap Flag
ScaleMin
0.0
ScaleMax
10.0
ValidMin
0.0
ValidMax
10.0
FillValue
-2147483648
Support
Qualifier
Scalar
SupportQuantity
Other
Parameter #23
Name
LANL 01A MPA Time Offset for Electron Measurements
ParameterKey
offset_time
Description

Time offset for electron measurements. Electron sample time is 21.5 seconds after that of ions.

Units
ms
RenderingHints
AxisLabel
T offset
ScaleMin
21500.0
ScaleMax
21500.0
ValidMin
21500.0
ValidMax
21500.0
FillValue
-1.0000e+031
Support
Qualifier
Scalar
SupportQuantity
Temporal