2.7.1 spase://NASA/NumericalData/TRACERS/TRACERS2/Level2/AnalyzerCuspElectrons/DEF/Variable NASA NumericalData TRACERS 2 Analyzer of Cusp Electrons (ACE) Differential Energy Flux and Counts, Level 2 (L2), Data https://doi.org/10.48322/vfwx-4a76 2026-04-30T14:30:23Z 2026-04-28T12:34:56.789 Initial release of metadata, ADAPT generated, SAB 2026-04-30T14:30:23Z 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. Added DOI. tlk The ACE L2 data consist of raw measured counts and calibrated differential energy fluxes as a function of anode angle and calibrated energy. Counts are accumulated in 21 discrete anodes with different viewing angles for each of 49 energy steps, with a basic measurement cadence of 50 ms. Counts are converted to differential energy flux by subtracting an estimate of the background and then dividing by the instrument calibration matrix. The estimated background count rates and calibration matrix are included in the L2 data files, enabling application of alternative background subtraction methods or calibrations. Background estimates include two sources: 1) Instrumental background due to electronics crosstalk, which is constant across all anodes but varies with energy. 2) Natural background due to penetrating energetic particles and natural radioactivity in the microchannel plate detectors, which is constant across all anodes and energies. Subtraction of background can lead to negative differential energy fluxes, especially for low count rate data. Depending on the use case, these negative values can either be retained or replaced with zeroes. The calibration matrix incorporates instrument sensitivity and relative sensitivity factors for each anode, both estimated based upon a combination of pre-flight laboratory calibrations and inflight data. Energy values for each energy step and anode are computed utilizing the known sweep voltage table and pre-flight laboratory calibrations. The ACE instrument was intended to be operated in a particular spacecraft orientation, with the TSCS +Z axis aligned with the magnetic field. In this orientation, incoming electron trajectories are not occluded by the spacecraft. However, for a portion of the TRACERS mission, the spacecraft are oriented in the opposite sense, which leads to an occlusion of a portion of the instrument field of view by the spacecraft body for low-energy (<~200 eV) electrons. Low-energy ACE data should not be utilized for quantitative purposes when the spacecraft are in this orientation. Jasper Halekas See the rules of use available at https://tracers.physics.uiowa.edu/rules-use. Halekas, Jasper, S.; Christopher, Ivar, W.; Miles, David, M. 2026-04-03T00:00:00Z Space Physics Data Facility spase://SMWG/Person/Jasper.S.Halekas InstrumentLead CoInvestigator spase://SMWG/Person/David.M.Miles PrincipalInvestigator spase://SMWG/Person/TRACERS_SOC HostContact spase://SMWG/Person/Lan.Jian MetadataContact spase://SMWG/Person/Scott.Boardsen MetadataContact TRACERS https://tracers.physics.uiowa.edu/ TRACERS data en Instrument Paper for Analyzer of Cusp Electrons (ACE) https://doi.org/10.1007/s11214-025-01147-9 Electron measurements from 20 eV to 13.5 keV, with angular resolution of 10x7 degrees, cadence of 50 ms to provide sub-kilometer resolution in the cusp in region of interest (ROI) and 6.4 s in back orbit (BOR). spase://SMWG/Repository/TRACERS_PDP Online Open HTTPS from the TRACERS SDC https://tracers.physics.uiowa.edu/l2-public-data-products In CDF via http from the TRACERS Science Data Center CDF None Please Acknowlege the TRACRES TEAM, for rules of use https:/tracers.physics.uiowa.edu/rules-use spase://SMWG/Repository/NASA/GSFC/SPDF/CDAWeb Online Open FTPS from SPDF (not with most browsers) ftps://spdf.gsfc.nasa.gov/pub/data/tracers/tracers2/ace_cusp-electrons/l2/def_diff-en-flux TS2_L2_ACE_DEF Access to Data in CDF Format via ftps from SPDF HTTPS from SPDF https://spdf.gsfc.nasa.gov/pub/data/tracers/tracers2/ace_cusp-electrons/l2/def_diff-en-flux HTTPS from SPDF. Note: this AccessURL element was added by HDPWS. HTTPS from SPDF https://cdaweb.gsfc.nasa.gov/pub/data/tracers/tracers2/ace_cusp-electrons/l2/def_diff-en-flux TS2_L2_ACE_DEF Access to Data in CDF Format via https from SPDF CDAWeb https://cdaweb.gsfc.nasa.gov/cgi-bin/eval2.cgi?dataset=TS2_L2_ACE_DEF&index=sp_phys TS2_L2_ACE_DEF Access to ASCII, CDF, and Plots via NASA/GSFC CDAWeb CDF None https://cdaweb.gsfc.nasa.gov/pub/data/tracers/tracers2/ace_cusp-electrons/l2/def_diff-en-flux/$Y ts2_l2_ace_def_$Y$m$d_$v.cdf Please acknowledge the Principal Investigator . Please acknowledge the Data Providers and CDAWeb when using these Data. spase://SMWG/Repository/NASA/GSFC/SPDF/CDAWeb Online Open CDAWeb HAPI Server https://cdaweb.gsfc.nasa.gov/hapi TS2_L2_ACE_DEF HAPI access to this data. Note: this AccessInformation element was added by HDPWS. CSV Please acknowledge the Principal Investigator . Please acknowledge the Data Providers and CDAWeb when using these Data. spase://SMWG/Repository/NASA/GSFC/SPDF Online Open CDAWeb Programmatic Data Access https://cdaweb.gsfc.nasa.gov/WS/cdasr/1/dataviews/sp_phys/datasets/TS2_L2_ACE_DEF/clientLibraryExample/ TS2_L2_ACE_DEF Access to this data from common programming environments. Note: this AccessInformation element was added by HDPWS. Binary Please acknowledge the Principal Investigator . Please acknowledge the Data Providers and CDAWeb when using these Data. Calibrated Level 2 spase://NASA/Instrument/TRACERS/AnalyzerCuspElectrons EnergeticParticles 2025-08-13T20:59:59.000 -P6M PT99999.999S Earth.Magnetosphere Earth.NearSurface.Ionosphere Earth.NearSurface.Ionosphere.Topside Earth.NearSurface.AuroralRegion Earth.NearSurface.PolarCap Currently no cavests. UTC epoch at sweep midpoint Epoch UTC epoch at midpoint of energy sweep ns 1.0e-9>s UTC Epoch I20 2022-02-01T00:00:00.000000000 2030-01-01T00:00:00.000000000 9999-12-31T23:59:59.999999999 Temporal ACE Electron Energy ts2_l2_ace_energy Energy at midpoint of ACE energy bins. eV e- Energy E11.4 LogScale 49 2.0000e+01 1.4290e+04 nan Electron Energy ACE Electron Energy Scaling by Anode ts2_l2_ace_energy_anode_factor Scaling factor for ACE energy at each anode. e Anode Energy Fac E11.4 LogScale 21 0.0000e+00 1.0000e+01 nan Housekeeping ACE Anode Angle in TSCS ts2_l2_ace_TSCS_anode_angle ACE anode angles from +Z-axis in TSCS frame. ° Anode Ang. F5.1 LinearScale 21 -10.0 190.0 nan DirectionAngle Orientation ACE Anode Num ts2_l2_ace_anode_number ACE anode number Anode Num I2 LinearScale 21 1 21 65535 Housekeeping ACE Anode Electron Velocity (TSCS) ts2_l2_ace_TSCS_anode_velocity_dir_xyz ACE anode electron velocity direction in TSCS frame. ° ACE e- Vel E11.4 LinearScale 3 21 nan DirectionAngle Orientation ACE Differential Energy Flux Time series defined by using: Epoch ts2_l2_ace_def Electron differential energy flux at 49 energies over 21 look directions.. * Column 1 Labels from TS2_L2_ACE_ENERGY: ["E1","E2","E3","E4","E5","E6","E7","E8","E9","E10","E11","E12","E13","E14","E15","E16","E17","E18","E19","E20","E21","E22","E23","E24","E25","E26","E27","E28","E29","E30","E31","E32","E33","E34","E35","E36","E37","E38","E39","E40","E41","E42","E43","E44","E45","E46","E47","E48","E49"]. * Column 2 Labels from TS2_L2_ACE_TSCS_ANODE_ANGLE: ["Anode -10.0","Anode 0.0","Anode 10.0","Anode 20.0","Anode 30.0","Anode 40.0","Anode 50.0","Anode 60.0","Anode 70.0","Anode 80.0","Anode 90.0","Anode 100.0","Anode 110.0","Anode 120.0","Anode 130.0","Anode 140.0","Anode 150.0","Anode 160.0","Anode 170.0","Anode 180.0","Anode 190.0"]. PT99999.999S eV eV!E-1!Ncm!E-2!Nsr!E-1!Ns!E-1!N Spectrogram e- Flux E10.3 LogScale 49 21 nan Electron Differential EnergyFlux Electron Counts Time series defined by using: Epoch ts2_l2_ace_counts Electron raw counts at 49 energies over 21 look directions.. * Column 1 Labels from TS2_L2_ACE_ENERGY: ["E1","E2","E3","E4","E5","E6","E7","E8","E9","E10","E11","E12","E13","E14","E15","E16","E17","E18","E19","E20","E21","E22","E23","E24","E25","E26","E27","E28","E29","E30","E31","E32","E33","E34","E35","E36","E37","E38","E39","E40","E41","E42","E43","E44","E45","E46","E47","E48","E49"]. * Column 2 Labels from TS2_L2_ACE_TSCS_ANODE_ANGLE: ["Anode -10.0","Anode 0.0","Anode 10.0","Anode 20.0","Anode 30.0","Anode 40.0","Anode 50.0","Anode 60.0","Anode 70.0","Anode 80.0","Anode 90.0","Anode 100.0","Anode 110.0","Anode 120.0","Anode 130.0","Anode 140.0","Anode 150.0","Anode 160.0","Anode 170.0","Anode 180.0","Anode 190.0"]. PT99999.999S raw counts Spectrogram Counts I4 49 21 65535 Electron Counts Background Counts Time series defined by using: Epoch ts2_l2_ace_background_counts Background counts for each energy bin and anode.. * Column 1 Labels from TS2_L2_ACE_ENERGY: ["E1","E2","E3","E4","E5","E6","E7","E8","E9","E10","E11","E12","E13","E14","E15","E16","E17","E18","E19","E20","E21","E22","E23","E24","E25","E26","E27","E28","E29","E30","E31","E32","E33","E34","E35","E36","E37","E38","E39","E40","E41","E42","E43","E44","E45","E46","E47","E48","E49"]. * Column 2 Labels from TS2_L2_ACE_TSCS_ANODE_ANGLE: ["Anode -10.0","Anode 0.0","Anode 10.0","Anode 20.0","Anode 30.0","Anode 40.0","Anode 50.0","Anode 60.0","Anode 70.0","Anode 80.0","Anode 90.0","Anode 100.0","Anode 110.0","Anode 120.0","Anode 130.0","Anode 140.0","Anode 150.0","Anode 160.0","Anode 170.0","Anode 180.0","Anode 190.0"]. PT99999.999S background counts Spectrogram Bg Cnts E10.3 49 21 nan Electron Counts Calibration Matrix Time series defined by using: Epoch ts2_l2_ace_cal_matrix Counts to differential energy flux calibration matrix.. * Column 1 Labels from TS2_L2_ACE_ENERGY: ["E1","E2","E3","E4","E5","E6","E7","E8","E9","E10","E11","E12","E13","E14","E15","E16","E17","E18","E19","E20","E21","E22","E23","E24","E25","E26","E27","E28","E29","E30","E31","E32","E33","E34","E35","E36","E37","E38","E39","E40","E41","E42","E43","E44","E45","E46","E47","E48","E49"]. * Column 2 Labels from TS2_L2_ACE_TSCS_ANODE_ANGLE: ["Anode -10.0","Anode 0.0","Anode 10.0","Anode 20.0","Anode 30.0","Anode 40.0","Anode 50.0","Anode 60.0","Anode 70.0","Anode 80.0","Anode 90.0","Anode 100.0","Anode 110.0","Anode 120.0","Anode 130.0","Anode 140.0","Anode 150.0","Anode 160.0","Anode 170.0","Anode 180.0","Anode 190.0"]. PT99999.999S TBD Spectrogram Cal Matrix E10.3 49 21 nan Housekeeping