2.3.2 spase://NASA/NumericalData/MMS/3/FIELDS/DSP/Slow/Level2/ElectricFieldPowerSpectralDensity/PT16S MMS 3 Digital Signal Processor (DSP) Double Probe (ADP, SDP), Electric Field Power Spectral Density, Slow Survey MMS3_DSP_SLOW_L2_EPSD 2021-04-27T15:38:11Z The MMS electric field power spectral density (EPSD) is computed onboard by the Digital Signal Processor (DSP). The fast Fourier transform (FFT) calculation is performed on a digitized version of analog signals from the Axial Double Probe (ADP) and Spin-Plane Double Probe (SDP). This data product is computed in space from individual components that are not synchronized to the 1 second pulse. Therefore, the timing between channels can be inaccurate by a fraction of a second. The samples times are interval start times taken from the x component. The spectra are calculated via a 1024-point FFT algorithm on piecewise continuous sets of waveform data. Nine signals can be processed simultaneously. Six of the twelve DC-coupled E, DC-coupled V, or SCM signals (16384 samples/s) are selected for spectral processing at 100% duty cycle. In addition, the three AC-coupled signals (262,144 kS/s) each can be processed at 6.25% duty cycle. Each of the nine signals has 16, 1024-point FFT operations every second; the field-programmable gate array (FPGA) performs 144 FFTs per second. The FFT is performed by an arithmetic logic unit (ALU), which is controlled by a state machine. Both are hard-coded into the FPGA. The operation starts by applying a 1024-point Hanning window onto a waveform. Next, an FFT is implemented. The FFT is broken into a series of "butterfly" operations performed by the ALU. The result has real and imaginary data. Power spectra are calculated by taking the sum of squares of real and imaginary values (the ALU includes a multiplier), which produces a power spectrum with 512 frequency bins. The frequency bins are then combined to give pseudo-logarithmic frequency spacing (del f)/f. The spectra are reduced to 56 frequency bins with (del f)/f between 6% and 12% when possible. Narrow-band emissions can be fit to an accuracy of (del f)/f ~3%, allowing for an accurate determination of plasma density. The spectra can be averaged in time. The fastest reporting rate of any signal is 16 spectra per second. Reporting rates can be as slow a one spectra every 16 s (averaging 256 spectra). The averaging process has 48-bit accuracy to maximize the dynamic range. The amplitudes undergo a pseudo-logarithmic compression to an 8-bit number representing over 120 dB of dynamic range at ~5% precision. J. Burch, R. Ergun spase://SMWG/Person/James.L.Burch PrincipalInvestigator spase://SMWG/Person/Robert.E.Ergun PrincipalInvestigator spase://SMWG/Person/Robert.E.McGuire 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). spase://VSPO/NumericalData/MMS/3/FIELDS/DSP/Slow/Level2/ElectricFieldPowerSpectralDensity/PT16S spase://SMWG/Repository/NASA/GSFC/SPDF Online Open FTPS from SPDF (not with most browsers) ftps://spdf.gsfc.nasa.gov/pub/data/mms/mms3/dsp/slow/l2/epsd/ In CDF via ftp from SPDF. HTTPS from SPDF https://spdf.gsfc.nasa.gov/pub/data/mms/mms3/dsp/slow/l2/epsd/ In CDF via http from SPDF. CDAWeb https://cdaweb.gsfc.nasa.gov/cgi-bin/eval2.cgi?dataset=MMS3_DSP_SLOW_L2_EPSD&index=sp_phys MMS3_DSP_SLOW_L2_EPSD Access to ASCII, CDF, and plots via NASA/GSFC CDAWeb CDF None J. Burch, R. Ergun. Please acknowledge the data providers and CDAWeb when using these data. spase://SMWG/Repository/NASA/GSFC/SPDF Online Open CDAWeb HAPI Server https://cdaweb.gsfc.nasa.gov/hapi MMS3_DSP_SLOW_L2_EPSD Web Service to this product using the HAPI interface. CSV J. Burch, R. Ergun. Please acknowledge the data providers and CDAWeb when using these data. Calibrated spase://SMWG/Instrument/MMS/3/FIELDS/ADP spase://SMWG/Instrument/MMS/3/FIELDS/DSP spase://SMWG/Instrument/MMS/3/FIELDS/SDP ElectricField Waves.Passive 2015-05-06T00:00:00.000 -P2M PT16S Earth.Magnetosheath Earth.Magnetosphere Earth.Magnetosphere.Magnetotail Earth.Magnetosphere.Main Earth.Magnetosphere.RadiationBelt Earth.NearSurface.EquatorialRegion Earth.NearSurface.Plasmasphere Heliosphere.NearEarth Epoch Epoch Epoch This parameter exhibits an increasing monotonic progression. PT16S ns 1.0e-9>s Epoch LinearScale 2000-01-01T00:00:00.000000000 2030-01-01T00:00:00.999000000 9999-12-31T23:59:59.999999999 Temporal Epoch_timetag Epoch_timetag Epoch Time Tag This parameter exhibits an increasing monotonic progression. PT16S ns 1.0e-9>s Epoch_timetag e14.8 LinearScale 1970-01-01T00:00:00.000000000 2030-01-01T00:00:00.999999999 9999-12-31T23:59:59.999999999 Temporal mms3_dsp_epsd_x Time series defined by using: EPOCH mms3_dsp_epsd_x EPSD, X-Component Average Type: standard PT16S (V/m)^2/Hz Cartesian SC Spectrogram e13.6 LogScale 88 1 1 8.0 2 2 24.0 3 3 40.0 4 4 56.0 5 5 72.0 6 6 88.0 7 7 104.0 8 8 120.0 9 9 136.0 10 10 152.0 11 11 168.0 12 12 184.0 13 13 200.0 14 14 216.0 15 15 232.0 16 16 248.0 17 17 272.0 18 18 304.0 19 19 336.0 20 20 368.0 21 21 400.0 22 22 432.0 23 23 464.0 24 24 496.0 25 25 544.0 26 26 608.0 27 27 672.0 28 28 736.0 29 29 800.0 30 30 864.0 31 31 928.0 32 32 992.0 33 33 1088.0 34 34 1216.0 35 35 1344.0 36 36 1472.0 37 37 1600.0 38 38 1728.0 39 39 1856.0 40 40 1984.0 41 41 2176.0 42 42 2432.0 43 43 2688.0 44 44 2944.0 45 45 3200.0 46 46 3456.0 47 47 3712.0 48 48 3968.0 49 49 4352.0 50 50 4864.0 51 51 5376.0 52 52 5888.0 53 53 6400.0 54 54 6912.0 55 55 7424.0 56 56 7936.0 57 57 8704.0 58 58 9728.0 59 59 10752.0 60 60 11776.0 61 61 12800.0 62 62 13824.0 63 63 14848.0 64 64 15872.0 65 65 17408.0 66 66 19456.0 67 67 21504.0 68 68 23552.0 69 69 25600.0 70 70 27648.0 71 71 29696.0 72 72 31744.0 73 73 34816.0 74 74 38912.0 75 75 43008.0 76 76 47104.0 77 77 51200.0 78 78 55296.0 79 79 59392.0 80 80 63488.0 81 81 69632.0 82 82 77824.0 83 83 86016.0 84 84 94208.0 85 85 102400.0 86 86 110592.0 87 87 118784.0 88 88 126976.0 0.0 2.0e-05 -1.0e+31 PlasmaWaves Component.I Intensity mms3_dsp_epsd_y Time series defined by using: EPOCH mms3_dsp_epsd_y EPSD, Y-Component Average Type: standard PT16S (V/m)^2/Hz Cartesian SC Spectrogram e13.6 LogScale 88 1 1 8.0 2 2 24.0 3 3 40.0 4 4 56.0 5 5 72.0 6 6 88.0 7 7 104.0 8 8 120.0 9 9 136.0 10 10 152.0 11 11 168.0 12 12 184.0 13 13 200.0 14 14 216.0 15 15 232.0 16 16 248.0 17 17 272.0 18 18 304.0 19 19 336.0 20 20 368.0 21 21 400.0 22 22 432.0 23 23 464.0 24 24 496.0 25 25 544.0 26 26 608.0 27 27 672.0 28 28 736.0 29 29 800.0 30 30 864.0 31 31 928.0 32 32 992.0 33 33 1088.0 34 34 1216.0 35 35 1344.0 36 36 1472.0 37 37 1600.0 38 38 1728.0 39 39 1856.0 40 40 1984.0 41 41 2176.0 42 42 2432.0 43 43 2688.0 44 44 2944.0 45 45 3200.0 46 46 3456.0 47 47 3712.0 48 48 3968.0 49 49 4352.0 50 50 4864.0 51 51 5376.0 52 52 5888.0 53 53 6400.0 54 54 6912.0 55 55 7424.0 56 56 7936.0 57 57 8704.0 58 58 9728.0 59 59 10752.0 60 60 11776.0 61 61 12800.0 62 62 13824.0 63 63 14848.0 64 64 15872.0 65 65 17408.0 66 66 19456.0 67 67 21504.0 68 68 23552.0 69 69 25600.0 70 70 27648.0 71 71 29696.0 72 72 31744.0 73 73 34816.0 74 74 38912.0 75 75 43008.0 76 76 47104.0 77 77 51200.0 78 78 55296.0 79 79 59392.0 80 80 63488.0 81 81 69632.0 82 82 77824.0 83 83 86016.0 84 84 94208.0 85 85 102400.0 86 86 110592.0 87 87 118784.0 88 88 126976.0 0.0 2.0e-05 -1.0e+31 PlasmaWaves Component.J Intensity mms3_dsp_epsd_z Time series defined by using: EPOCH mms3_dsp_epsd_z EPSD, Z-Component Average Type: standard PT16S (V/m)^2/Hz Cartesian SC Spectrogram e13.6 LogScale 88 1 1 8.0 2 2 24.0 3 3 40.0 4 4 56.0 5 5 72.0 6 6 88.0 7 7 104.0 8 8 120.0 9 9 136.0 10 10 152.0 11 11 168.0 12 12 184.0 13 13 200.0 14 14 216.0 15 15 232.0 16 16 248.0 17 17 272.0 18 18 304.0 19 19 336.0 20 20 368.0 21 21 400.0 22 22 432.0 23 23 464.0 24 24 496.0 25 25 544.0 26 26 608.0 27 27 672.0 28 28 736.0 29 29 800.0 30 30 864.0 31 31 928.0 32 32 992.0 33 33 1088.0 34 34 1216.0 35 35 1344.0 36 36 1472.0 37 37 1600.0 38 38 1728.0 39 39 1856.0 40 40 1984.0 41 41 2176.0 42 42 2432.0 43 43 2688.0 44 44 2944.0 45 45 3200.0 46 46 3456.0 47 47 3712.0 48 48 3968.0 49 49 4352.0 50 50 4864.0 51 51 5376.0 52 52 5888.0 53 53 6400.0 54 54 6912.0 55 55 7424.0 56 56 7936.0 57 57 8704.0 58 58 9728.0 59 59 10752.0 60 60 11776.0 61 61 12800.0 62 62 13824.0 63 63 14848.0 64 64 15872.0 65 65 17408.0 66 66 19456.0 67 67 21504.0 68 68 23552.0 69 69 25600.0 70 70 27648.0 71 71 29696.0 72 72 31744.0 73 73 34816.0 74 74 38912.0 75 75 43008.0 76 76 47104.0 77 77 51200.0 78 78 55296.0 79 79 59392.0 80 80 63488.0 81 81 69632.0 82 82 77824.0 83 83 86016.0 84 84 94208.0 85 85 102400.0 86 86 110592.0 87 87 118784.0 88 88 126976.0 0.0 2.0e-05 -1.0e+31 PlasmaWaves Component.K Intensity mms3_dsp_epsd_omni Time series defined by using: EPOCH mms3_dsp_epsd_omni EPSD, Omni-directional Average Type: standard PT16S (V/m)^2/Hz Spectrogram e13.6 LogScale 88 1 1 8.0 2 2 24.0 3 3 40.0 4 4 56.0 5 5 72.0 6 6 88.0 7 7 104.0 8 8 120.0 9 9 136.0 10 10 152.0 11 11 168.0 12 12 184.0 13 13 200.0 14 14 216.0 15 15 232.0 16 16 248.0 17 17 272.0 18 18 304.0 19 19 336.0 20 20 368.0 21 21 400.0 22 22 432.0 23 23 464.0 24 24 496.0 25 25 544.0 26 26 608.0 27 27 672.0 28 28 736.0 29 29 800.0 30 30 864.0 31 31 928.0 32 32 992.0 33 33 1088.0 34 34 1216.0 35 35 1344.0 36 36 1472.0 37 37 1600.0 38 38 1728.0 39 39 1856.0 40 40 1984.0 41 41 2176.0 42 42 2432.0 43 43 2688.0 44 44 2944.0 45 45 3200.0 46 46 3456.0 47 47 3712.0 48 48 3968.0 49 49 4352.0 50 50 4864.0 51 51 5376.0 52 52 5888.0 53 53 6400.0 54 54 6912.0 55 55 7424.0 56 56 7936.0 57 57 8704.0 58 58 9728.0 59 59 10752.0 60 60 11776.0 61 61 12800.0 62 62 13824.0 63 63 14848.0 64 64 15872.0 65 65 17408.0 66 66 19456.0 67 67 21504.0 68 68 23552.0 69 69 25600.0 70 70 27648.0 71 71 29696.0 72 72 31744.0 73 73 34816.0 74 74 38912.0 75 75 43008.0 76 76 47104.0 77 77 51200.0 78 78 55296.0 79 79 59392.0 80 80 63488.0 81 81 69632.0 82 82 77824.0 83 83 86016.0 84 84 94208.0 85 85 102400.0 86 86 110592.0 87 87 118784.0 88 88 126976.0 0.0 2.0e-05 -1.0e+31 PlasmaWaves Total Intensity mms3_dsp_seqcnt_lfe Time series defined by using: EPOCH_TIMETAG mms3_dsp_seqcnt_lfe Sequence Count PT16S TimeSeries i6 LinearScale 0 65535 65535 Other mms3_e_freq mms3_e_freq EPSD, Frequency Midpoints PT16S e10.6 88 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10 11 11 12 12 13 13 14 14 15 15 16 16 17 17 18 18 19 19 20 20 21 21 22 22 23 23 24 24 25 25 26 26 27 27 28 28 29 29 30 30 31 31 32 32 33 33 34 34 35 35 36 36 37 37 38 38 39 39 40 40 41 41 42 42 43 43 44 44 45 45 46 46 47 47 48 48 49 49 50 50 51 51 52 52 53 53 54 54 55 55 56 56 57 57 58 58 59 59 60 60 61 61 62 62 63 63 64 64 65 65 66 66 67 67 68 68 69 69 70 70 71 71 72 72 73 73 74 74 75 75 76 76 77 77 78 78 79 79 80 80 81 81 82 82 83 83 84 84 85 85 86 86 87 87 88 88 8.0 126976.0 -1.0e+31 Other