2.7.1 https://spdx.org/licenses/ SPDX 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/MMS/4/ASPOC/Survey/Level2/PT1S NASA NumericalData MMS 4 Active Spacecraft Potential Control (ASPOC), Sensors 1 and 2, Level 2 (L2), Survey Mode, 1 s Data MMS4_ASPOC_SRVY_L2 https://doi.org/10.48322/3470-wp93 2025-12-04T13:30:09Z 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 ASPOC team, metadata updated to SPASE 2.5.0, reviewed by LFB 20230304 2025-10-03T10:41:10Z Updated PublishedBy name to match ROR Registry. Added ResourceType and NamingAuthority. Changed http to https in top-level schemaLocation attribute. Fixed version number separator in top-level schemaLocation attribute. Matched version number in schemaLocation attribute to updated value in Version tag. ZCB 2025-12-04T13:30:09Z Added MetadataRightsList and RightsList(s). Updated to 2.7.1. ZCB MMS 4 Active Spacecraft Potential Control (ASPOC) - Sensors 1 and 2 Ion Beam Current Rates, Beam Energies, and Instrument Status variables. In tenuous plasma regions, the floating potential of a sunlit spacecraft is positively charged, reaching up to tens of Volts. The corresponding electric field disturbs the ambient plasma measurements obtained from electron and ion sensors and the large fluxes of attracted photo-electrons can significantly reduce the lifetime of the micro-channel plate. The electric field measurements can be also contaminated by the high spacecraft potential values. The Active Spacecraft Potential Control neutralizes the spacecraft potential by releasing positively charged Indium ions. The ASPOCs neutralize the electrical potential of the spacecraft, limiting or eliminating spurious electric fields that can contaminate measurements. This allows observations of the more scientifically important low-energy ions and electrons. Please acknowledge R. Nakamura, K.M. Torkar, H. Jeszenszky, and J.L. Burch for use of these data Nakamura, Rumi; Torkar, Klaus, M.; Jeszenszky, Harald; Burch, James, L. 2022-01-01T00:00:00 Laboratory for Atmospheric and Space Physics; Space Physics Data Facility spase://SMWG/Person/Rumi.Nakamura InstrumentLead CoInvestigator spase://SMWG/Person/Klaus.M.Torkar InstrumentLead CoInvestigator Retired spase://SMWG/Person/Harald.Jeszenszky TechnicalContact 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/aspoc/ 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. The MMS Graz ASPOC Team home page at IWF, OAW https://www.oeaw.ac.at/en/iwf/research/space-missions/current-missions/magnetospheric-multiscale/aspoc The Magnetospheric Multiscale (MMS) ASPOC home page hosted by the Graz ASPOC team located at the Institut fur Weltraumforschung (IWF), Osterreichische Akademie der Wissenschaften (OAW). spase://VSPO/NumericalData/MMS/4/ASPOC/Survey/Level2/PT1S 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/mms4/aspoc/srvy/l2/ In CDF via ftp from the MMS Science Data Center HTTPS from the MMS SDC https://lasp.colorado.edu/mms/sdc/public/data/mms4/aspoc/srvy/l2/ In CDF via http from the MMS Science Data Center CDF None Please acknowledge R. Nakamura, K.M. Torkar, H. Jeszenszky, 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 https://spdx.org/licenses/ SPDX 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/mms/mms4/aspoc/srvy/l2/ In CDF via ftp from SPDF HTTPS from SPDF https://spdf.gsfc.nasa.gov/pub/data/mms/mms4/aspoc/srvy/l2/ In CDF via http from SPDF CDAWeb https://cdaweb.gsfc.nasa.gov/cgi-bin/eval2.cgi?dataset=MMS4_ASPOC_SRVY_L2&index=sp_phys MMS4_ASPOC_SRVY_L2 Access to ASCII, CDF, and plots via NASA/GSFC CDAWeb CDF None Please acknowledge R. Nakamura, K.M. Torkar, H. Jeszenszky, 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 https://spdx.org/licenses/ SPDX 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 MMS4_ASPOC_SRVY_L2 Web Service to this product using the HAPI interface CSV Please acknowledge R. Nakamura, K.M. Torkar, H. Jeszenszky, and J.L. Burch. Also please acknowledge the data providers and CDAWeb when using these data. Calibrated spase://SMWG/Instrument/MMS/4/InstrumentControl/ASPOC InstrumentStatus 2015-04-19T00:00:00.000 -P2M PT1S Earth.Magnetosheath Earth.Magnetosphere Earth.Magnetosphere.Magnetotail Earth.Magnetosphere.Main Earth.Magnetosphere.RadiationBelt Earth.NearSurface.EquatorialRegion Earth.NearSurface.Plasmasphere Heliosphere.NearEarth Epoch Epoch Interval centered time tag rounded to nearest msecond This parameter exhibits an increasing monotonic progression. PT1S ns 1.0e-9>s TimeSeries Epoch 6.2798349819904e+13 6.6269642620904e+13 LinearScale 1990-01-01T00:00:00.000000000 2100-01-01T00:00:01.000000000 9999-12-31T23:59:59.999999999 Temporal Beam Current Sum Time series defined by using: EPOCH mms4_aspoc_ionc ASPOC Ion Emission Current Sum PT1S uA 1.0e-6>A TimeSeries I_ion f5.1 0.0 100.0 LinearScale 0.0 100.0 -1.0e+31 Ion Median CountRate Beam Current, Unit 1 Time series defined by using: EPOCH mms4_asp1_ionc ASPOC Unit 1 Ion Emission Current PT1S uA 1.0e-6>A TimeSeries I_ion f5.1 0.0 100.0 LinearScale 0.0 100.0 -1.0e+31 Ion Median CountRate Beam Current, Unit 2 Time series defined by using: EPOCH mms4_asp2_ionc ASPOC Unit 2 Ion Emission Current PT1S uA 1.0e-6>A TimeSeries I_ion f5.1 0.0 100.0 LinearScale 0.0 100.0 -1.0e+31 Ion Median CountRate Beam Energy, Unit 1 Time series defined by using: EPOCH mms4_asp1_energy ASPOC Unit 1 Emitted Beam Energy PT1S kV 1.0e3>V TimeSeries Energy f5.2 0.0 12.5 LinearScale 0.0 12.5 -1.0e+31 Ion Median Energy Beam Energy, Unit 2 Time series defined by using: EPOCH mms4_asp2_energy ASPOC Unit 2 Emitted Beam Energy PT1S kV 1.0e3>V TimeSeries Energy f5.2 0.0 12.5 LinearScale 0.0 12.5 -1.0e+31 Ion Median Energy Instrument Status Time series defined by using: EPOCH mms4_aspoc_status ASPOC Instrument Status PT1S TimeSeries i3 LinearScale 4 Data Quality 1 Data Quality Unit 1 Mode 2 Unit 1 Mode Unit 2 Mode 3 Unit 2 Mode On/Off Status 4 On/Off Status 0 254 255 InstrumentMode Half Interval mms4_aspoc_var Half width of measurement interval PT1S ns 1.0e-9>s Half_int f13.1 0.0 1.275e+10 Temporal