2.7.2 https://spdx.org/licenses/ CC0-1.0 https://spdx.org/licenses/CC0-1.0.html Creative Commons Zero v1.0 Universal CC0 1.0 Universal is the Creative Commons license applicable to all publicly available SPASE metadata descriptions spase://NASA/NumericalData/IMP8/Ephemeris/PT12M NASA NumericalData IMP 8 Spacecraft Positions 2026-09-25T13:32:37 2021-04-27T15:38:11Z Only known prior ReleaseDate of the metadata 2025-05-14T15:38:11Z Added ObservedRegion. JMW 2025-12-04T13:29:34Z Added MetadataRightsList and RightsList(s). Added ResourceType and NamingAuthority. Updated to 2.7.1. Changed http to https in top-level schemaLocation attribute. Fixed version number separator in top-level schemaLocation attribute. ZCB 2026-07-21T12:05:22Z Added HelioData InformationURL. JWL 2026-09-25T13:32:37 Added Publication Info IMP-8 spacecraft positions in various coordinate systems McGuire, Robert E. 2021-04-27T15:38:11Z Space Physics Data Facility spase://SMWG/Person/Adam.Szabo Scientist spase://SMWG/Person/Robert.E.McGuire ProjectScientist HelioData https://helio.data.nasa.gov/dataset/IMP8_Ephemeris_PT12M The HelioData dataset page provides an overview of the dataset with access links, associated variables, and more. spase://VMO/NumericalData/IMP8/Ephemeris/PT12M spase://VSPO/NumericalData/IMP8/Ephemeris/PT12M spase://SMWG/Repository/NASA/GSFC/SPDF/CDAWeb Online Open https://spdx.org/licenses/ CC0-1.0 https://spdx.org/licenses/CC0-1.0.html Creative Commons Zero v1.0 Universal CC0 1.0 Universal is the Creative Commons license applicable to all publicly available NASA Heliophysics data products FTPS from SPDF (not with most browsers) ftps://spdf.gsfc.nasa.gov/pub/data/imp/imp8/orbit/or_ssc/ NASA/GSFC CDAWeb ftp access to the data. HTTPS from SPDF https://spdf.gsfc.nasa.gov/pub/data/imp/imp8/orbit/or_ssc/ In CDF via HTTP from SPDF CDF None spase://SMWG/Repository/NASA/GSFC/SPDF Online Open https://spdx.org/licenses/ CC0-1.0 https://spdx.org/licenses/CC0-1.0.html Creative Commons Zero v1.0 Universal CC0 1.0 Universal is the Creative Commons license applicable to all publicly available NASA Heliophysics data products CDAWeb https://cdaweb.gsfc.nasa.gov/cgi-bin/eval2.cgi?dataset=I8_OR_SSC&index=sp_phys I8_OR_SSC I8_OR_SSC with subset, plot and list via CDAWeb SSCWeb https://sscweb.gsfc.nasa.gov/cgi-bin/Locator.cgi imp8 Text https://cdaweb.gsfc.nasa.gov/pub/data/imp/imp8/orbit/or_ssc i8_or_ssc_$Y$m$d_$v.cdf Please acknowledge the CDAWeb team at GSFC/SPDF. spase://SMWG/Repository/NASA/GSFC/SPDF Online Open CDAWeb Programmatic Data Access https://cdaweb.gsfc.nasa.gov/WS/cdasr/1/dataviews/sp_phys/datasets/I8_OR_SSC/clientLibraryExample/ I8_OR_SSC Access to this data from common programming environments. Note: this AccessInformation element was added by HDPWS. Binary Please acknowledge the CDAWeb team at GSFC/SPDF. spase://SMWG/Repository/NASA/GSFC/SPDF Online Open SSCWeb Programmatic Data Access https://sscweb.gsfc.nasa.gov/WS/sscr/2/observatories/I8_OR_SSC/clientLibraryExample/ I8_OR_SSC Access to this data from common programming environments. Note: this AccessInformation element was added by HDPWS. Binary Please acknowledge the CDAWeb team at GSFC/SPDF. spase://SMWG/Repository/NASA/GSFC/SPDF Online Open 4D Orbit Viewer https://sscweb.gsfc.nasa.gov/4dorbit/?sc=I8_OR_SSC I8_OR_SSC 4D viewer for this data. Note: this AccessInformation element was added by HDPWS. HTML Please acknowledge the CDAWeb team at GSFC/SPDF. spase://SMWG/Repository/NASA/GSFC/SPDF Online Open https://spdx.org/licenses/ CC0-1.0 https://spdx.org/licenses/CC0-1.0.html Creative Commons Zero v1.0 Universal CC0 1.0 Universal is the Creative Commons license applicable to all publicly available NASA Heliophysics data products CDAWeb HAPI Server https://cdaweb.gsfc.nasa.gov/hapi I8_OR_SSC Web Service to this product using the HAPI interface. CSV Please acknowledge the CDAWeb team at GSFC/SPDF. spase://SMWG/Instrument/IMP8/Ephemeris Ephemeris 1973-10-30T00:00:00Z P0D PT12M Heliosphere.NearEarth Earth.Magnetosphere.Magnetotail Epoch Epoch Number of milliseconds since the epoch 01-Jan-1956 00:00:00 ms 1e-3>s -1.0e31 Temporal GSE Latitude GSE_LAT Spacecraft latitude in GSE coordinates deg Spherical GSE -90.0 90.0 -1.0e+31 DirectionAngle.ElevationAngle Positional GSE Longitude GSE_LON Spacecraft longitude in GSE coordinates deg Spherical GSE 0.0 360.0 -1.0e+31 DirectionAngle.AzimuthAngle Positional GSE Local Time GSE_LCT_T Local time in GSE coordinates hr 3600>s Spherical GSE 0.0 24.0 -1.0e+31 DirectionAngle.AzimuthAngle Positional GSM Latitude GSM_LAT Spacecraft latitude in GSM coordinates deg Spherical GSM -90.0 90.0 -1.0e+31 DirectionAngle.ElevationAngle Positional GSM Longitude GSM_LON Spacecraft longitude in GSM coordinates deg Spherical GSM 0.0 360.0 -1.0e+31 DirectionAngle.AzimuthAngle Positional Radial distance RADIUS Radial distance from the center of Earth Re 6.378e6>m Spherical GSE 0.0 250.0 -1.0e+31 Magnitude Positional GSE Position Vector XYZ_GSE Position in cartesian GSE coordinates Re 6.378e6>m Cartesian GSE 3 GSE X Component.I 1 GSE Y Component.J 2 GSE Z Component.K 3 -250.0 250.0 -1.0e+31 Positional GSM Position Vector XYZ_GSM Position in cartesian GSM coordinates Re 6.378e6>m Cartesian GSM 3 GSM X Component.I 1 GSM Y Component.J 2 GSM Z Component.K 3 -250.0 250.0 -1.0e+31 Positional