2.2.2 spase://VWO/NumericalData/DynamicsExplorer1/Ephemeris/PT8S DE1 8 sec Position Data DE1 8 Second Orbit and Attitude Data 2014-05-15T00:00:00.000 Two Dynamics Explorer (DE) spacecraft were launched August 3, 1981, and placed into coplanar polar orbits with DE-1 in a highly elliptical orbit and DE-2 in a lower more circular orbit. The primary objective of the DE program was to investigate magnetosphere-ionosphere-atmosphere coupling processes. The DE mission provided a wealth of new information on a wide variety of magnetospheric plasma wave phenomena including auroral kilometric radiation, auroral hiss, Z mode radiation, narrow-band electromagnetic emissions associated with equatorial upper hybrid waves, whistler mode emissions, wave-particle interactions stimulated by ground VLF transmitters, equatorial ion cyclotron emissions, ion Bernstein mode emissions, and electric field turbulence along the auroral field lines. These files contain 8 second resolution emphemeris and spacecraft attitude parameters that coincide with DE-1 telemetry frames containing PWI lowrate data. These parameters are not to be taken as an authoritative set, but are convenient when working with PWI science data products. Most of these data are provided in the Geocentric Equatorial Inertial (GEI) TOD reference frame. The Z axis of the GEI frame is parallel to Earth's spin axis; the X axis points towards the First Point of Aries with the Y axis aligned so as to generate a right-handed coordinate system. Users of the DE-1 PWI data are encouraged to acknowledge NASA CDAWeb and The University of Iowa as the source of the data in any publication. spase://SMWG/Person/Donald.A.Gurnett PrincipalInvestigator spase://SMWG/Person/Jolene.S.Pickett MetadataContact spase://SMWG/Person/Larry.J.Granroth MetadataContact spase://SMWG/Person/Chris.W.Piker MetadataContact The University of Iowa DE-1 PWI Page http://www-pw.physics.uiowa.edu/de/home.html en spase://SMWG/Repository/NASA/GSFC/SPDF Online Open HTTP access to files at the University of Iowa http://www-pw.physics.uiowa.edu/de/data/lowrate/cdf/ de1_pwi_or-at Direct link to CDF format data via FTP from the SPDF. CDF None Users of the DE-1 PWI data are encouraged to acknowledge NASA CDAWeb and The University of Iowa as the source of the data in any publication. Calibrated spase://SMWG/Instrument/DynamicsExplorer1/Ephemeris Ephemeris 1981-09-16T05:21:48 1984-06-28T20:35:55 PT8S Epoch Epoch NSSDC standard reference time associated with the start of a PWI SFR sweep ms Temporal GEI Velocity GEI_velocity GEI (Geocentric Equatorial Inertial) Satellite Velocity Vector (km/sec). The order of the vector components is v(x), v(y), v(z). km/sec Cartesian GEI Velocity Altitude Altitude Altitude above a spheroid Earth, not above the geoid. km Positional Geographic Latitude GLAT Geographic latitude of subsatellite point in degrees degrees Spherical GEO -90.0 90.0 Positional Geographic Longitude GLON Geographic longitude of the satellite in degrees degrees Spherical GEO -180.0 180.0 Positional MLT MLT Magnetic Local Time. MLT was defined via the conventional Solar Magnetic frame. hours 0.0 24.0 Positional L Shell L_Shell McIlwain's shell parameter (L) Re Positional Invariant Latitude ILAT Current spacecraft field line footprint's geomagnetic latitude. degrees -90.0 90.0 Positional B Magnitude B_Magnitude Magnetic field strength. Any discrepancy between these data and those provided by the magnetometer instrument's own files should be resolved in favor of the latter. See 'Magnetic Field Observations on DE-A and -B', W. H. Farthing, et al., Space Science Instrumentation 5 (1981) for more information. nT Magnetic B Vector (GEI) GEI_B_vec GEI (Geocentric Equatorial Inertial) Magnetic Vector in nanoTesla. The order of the vector components is B(x), B(y), B(z). Any discrepancy between these data and those provided by the magnetometer instrument's own files should be resolved in favor of the latter. See 'Magnetic Field Observations on DE-A and -B', W. H. Farthing, et al., Space Science Instrumentation 5 (1981) for more information. nT Magnetic Orbit Number Orbit_Number The orbit number from PWI archive files. Other GEI Rotation GEI_rotation 3-by-3 rotation matrix for the transformation from spacecraft coordinates to the GEI frame. The order of the elements is [1,1] = X(x), [1,2] = X(y), [1,3] = X(z), [2,1] = Y(x), [2,2] = Y(y), [2,3] = Y(z), [3,1] = Z(x), [3,2] = Z(y), and [3,3] = Z(z)" Positional GEI Position GEI_Position Spacecraft position in GEI coordinates, the order of the coordinates is X, Y, Z. Cartesian GEI Positional GEI Relative Velocity GEI_rel_vel GEI (Geocentric Equatorial Inertial) Satellite Velocity Vector (km/sec) relative to a rotating atmosphere. km/sec Cartesian GEI Velocity GEI Sun Position GEI_sun_pos GEI (Geocentric Equatorial Inertial) unit vector toward the sun. The order of the components is X, Y, Z. Cartesian GEI Positional Spin Phase Angle Spin_Angle Angle between the Velocity Vector and the Spacecraft X-axis Degrees -180.0 180.0 Positional SunFlag Sunlight Sunlight/Darkness flag, 0 = Darkness, 1 = Sunlight Other Re Re Geocentric radial distance in Earth Radii. Here 1 Re = 6378.2 km Re Positional Magnetic Latitude MLAT Magnetic latitude in degrees Degrees -90.0 90.0 Positional