Version:2.2.9

NumericalData

ResourceHeader

ResourceName

Polar Electric Fields Instrument (EFI), Spacecraft Attitude in GSE coordinates

ReleaseDate

2019-08-05 15:03:35Z

Description

the Polar spacecraft positive spin axis direction vector (normalized to magnitude 1), in GSE coordinates.

Acknowledgement

Please acknowledge the instrument PI, F.S. Mozer, and CDAWeb when using these data.

Contacts

	Role	Person
1.	PrincipalInvestigator	spase://SMWG/Person/Forrest.S.Mozer
2.	MetadataContact	spase://SMWG/Person/Jack.B.Vernetti
3.	MetadataContact	spase://SMWG/Person/Robert.E.McGuire
4.	MetadataContact	spase://SMWG/Person/Lee.Frost.Bargatze

PriorIDs

spase://VWO/NumericalData/POLAR/EFI/S_C_GSE_Attitude

spase://VSPO/NumericalData/POLAR/EFI/Attitude/PT10M

AccessInformation

RepositoryID

spase://SMWG/Repository/NASA/GSFC/SPDF

Availability

Online

AccessRights

Open

AccessURL

Name

FTP access to files at SPDF

URL

ftps://spdf.gsfc.nasa.gov/pub/data/polar/efi/efi_10minatt/

Description

Access to Data in CDF Format via ftp from SPDF

AccessURL

Name

HTTP access to files at SPDF

URL

https://spdf.gsfc.nasa.gov/pub/data/polar/efi/efi_10minatt/

Description

Access to Data in CDF Format via http from SPDF

AccessURL

Name

CDAWeb

URL

https://cdaweb.sci.gsfc.nasa.gov/cgi-bin/eval2.cgi?dataset=PO_10MINATT_EFI&index=sp_phys

ProductKey

PO_10MINATT_EFI

Description

Access to ASCII, CDF, and plots via NASA/GSFC CDAWeb

Format

CDF

Encoding

None

Acknowledgement

Please acknowledge the instrument PI, F.S. Mozer, and CDAWeb when using these data.

AccessInformation

RepositoryID

spase://SMWG/Repository/UCB/POLAR/EFI

Availability

Online

AccessRights

Open

AccessURL

Name

POLAR EFI data archive

URL

http://polarefi.ssl.berkeley.edu

Description

This URL is the root location of the POLAR EFI archive. It consists of Yearly subdirectories: 1996, 1997, ..., 2008 each of which consists of Monthly subdirectories: 01, 02, ..., 12 The archive files for a given date are located in the corresponding YY/MM subdirectory.

Language

en

Format

CDF

Encoding

None

Acknowledgement

The user will acknowledge, in any publication which uses POLAR EFI data, the instrument PI.

ProcessingLevel

Calibrated

MeasurementType

Ephemeris

TemporalDescription

TimeSpan

StartDate

1996-03-16 00:00:00

StopDate

2008-04-13 24:00:00

Cadence

PT600S

ObservedRegion

Earth.Magnetosphere

ObservedRegion

Earth.Magnetosphere.Polar

ObservedRegion

Earth.NearSurface

ObservedRegion

Earth.NearSurface.AuroralRegion

ObservedRegion

Earth.NearSurface.EquatorialRegion

ObservedRegion

Earth.NearSurface.Ionosphere

ObservedRegion

Earth.NearSurface.PolarCap

Caveats

Important Warning: The Data described below is meant for Archival Purposes. It should not be considered as highly accurate Data. For example, Accurate Data requires a Correction in the Form of an Offset to the Sunward Component of the Electric Field. A Constant Offset of 1.2 mV/m has been used for all the Data this being an approximate Average Value. In fact, however, the Offset varies with Time and must be determined by Analysis of the particular Time of Interest. Users of these Data desiring more Information should get in touch with Dr. F.S. Mozer, at the Space Sciences Laboratory, University of California, Berkeley. The Electric Field Data is at Spin Period Time Resolution. This means that there is one Data Point about every 6 s. However, it should be noted that there can be longer Intervals between Data Points due to Missing Data. Data Gaps are not filled in. The Components of the Electric Field are given in a Coordinate System designated as Despun Spacecraft Coordinates, DSC. This is a Coordinate System for a rotating Spacecraft that is in an Orbit near the Earth. DSC is defined by the Spacecraft's Spin Plane and Spin Axis. However, as the Despun Part of the Name suggests, the Coordinate Axes do not participate in the Spacecraft's Rotation. The X-Axis and Y-Axis are on the Spacecraft's Spin Plane; the Z-Axis is along the Spacecraft's Spin Axis. The positive X, Y, and Z-Axes form an Orthogonal, Right-Handed Coordinate System. The positive Z-Axis points in the same Direction as the Spacecraft's Angular Momentum, or Spin or Attitude, Vector. The positive X-Axis points in the Direction in the Spin Plane that is closest to the Direction towards the Sun. In other Words, the positive X-Axis points in the Direction of the Projection on the Spin Plane of the Vector from the Spacecraft to the Sun. The positive Y-Axis is determined by the Requirement that the DSC XYZ System form an Orthogonal Right-Handed System. It follows that the positive Y-Axis points in the Direction on the Spin Plane that is 90 degrees ahead of the positive X-Axis in the Sense of the Spacecraft's Rotation. The Electric Field Data included in these Files consists of the two Electric Field Components in the Spin Plane. The Original Data used is V34L, which typically has a Time Resolution of about 40 Data Points per Second. A Least-Squares Spin Fit of V34L is performed and the Spin Fit Coefficients provide the Spin Plane Components of the Spin Period Electric Field. Time is a Real Double Precision Quantity. The Units for the Time are Seconds. The Time is the Time elapsed since the Epoch starting on May 24, 1968 at 00:00:00 UT. Each Time Tag indicates the Mid-Point of the Time Interval for the corresponding Spin Period. Data Gaps are not filled and each Time Tag corresponds to an Actual Data Point. X, Y, and Z are the three Components of the Attitude Vector in the Geocentric Solar Ecliptic, GSE, Coordinate System.

Parameter #1

Name

Time

ParameterKey

TIME_TAG

Description

Data point time-tags which are double precision floating point numbers which represent the number of seconds, UTC, from midnight of the day represented by the file.

Cadence

PT600S

Units

seconds

ValidMin

0.0

ValidMax

86460.0

Support

SupportQuantity

Temporal

Parameter #2

Name

SCAttitudeGSEVector

ParameterKey

DATA_VALUES

Description

Data point vector values which are a triplet of single precision floating point numbers which represent the normalized X,Y,Z components of the GSE spacecraft attitude (i.e. the direction of the spacecraft positive spin axis).

Cadence

PT600S

Units

Numeric

UnitsConversion

1.0

CoordinateSystem

CoordinateRepresentation

Cartesian

CoordinateSystemName

GSE

ValidMin

-1.0

ValidMax

1.0

Support

SupportQuantity

Positional