2.2.2 spase://VMO/NumericalData/THEMIS/E/FBK/PT4S THEMIS-E: Probe Electric Field Instrument and Search Coil Magnetometer Instrument, Digital Fields Board - digitally computed Filter Bank spectra and E12 peak and average in HF band (FBK). 2009-05-20T23:06:02Z The Filter Bank is part of the Digital fields board and provides band-pass filtering for EFI and SCM spectra as well as E12HF peak and average value calculations. The Filter Bank provides band-pass filtering for less computationally and power intensive spectra than the FFT would provide. The process is as follows: Signals are fed to the Filter Bank via a low-pass FIR filter with a cut-off frequency half that of the original signal maximum. The output is passed to the band-pass filters, is differenced from the original signal, then absolute value of the data is taken and averaged. The output from the low-pass filter is also sent to a second FIR filter with 2:1 decimation. This output is then fed back through the system. The process runs through 12 cascades for input at 8,192 samples/s and 13 for input at 16,384 samples/sec (EAC input only), reducing the signal and computing power by a factor 2 at each cascade. At each cascade a set of data is produced at a sampling frequency of 2^n from 2 Hz to the initial sampling frequency (frequency characteristics for each step are shown below in Table 1). The average from the Filter Bank is compressed to 8 bits with a pseudo-logarithmic encoder. The data is stored in sets of six frequency bins at 2.689 kHz, 572 Hz, 144.2 Hz, 36.2 Hz, 9.05 Hz, and 2.26 Hz. The average of the coupled E12HF signal and it's peak value are recorded over 62.5 ms windows (i.e. a 16 Hz sampling rate). Accumulation of values from signal 31.25 ms windows is performed externally. The analog signals fed into the FBK are E12DC and SCM1. Sensor and electronics design provided by UCB (J. W. Bonnell, F. S. Mozer), Digital Fields Board provided by LASP (R. Ergun), Search coil data provided by CETP (A. Roux). Table 1: Frequency Properties. Cascade | Frequency content of Input Signal | Low-pass Filter Cutoff Frequency | Freuency Content of Low-pass Output Signal | Filter Bank Frequency Band 0* 0 - 8 kHz 4 kHz 0 - 4 kHz 4 - 8 kHz 1 0 - 4 kHz 2 kHz 0 - 2 kHz 2 - 4 kHz 2 0 - 2 kHz 1 kHz 0 - 1 kHz 1 - 2 kHz 3 0 - 1 kHz 512 Hz 0 - 512 Hz 512 Hz - 1 kHz 4 0 - 512 Hz 256 Hz 0 - 256 Hz 256 - 512 Hz 5 0 - 256 Hz 128 Hz 0 - 128 Hz 128 - 256 Hz 6 0 - 128 Hz 64 Hz 0 - 64 Hz 64 - 128 Hz 7 0 - 64 Hz 32 Hz 0 - 32 Hz 32 - 64 Hz 8 0 - 32 Hz 16 Hz 0 - 16 Hz 16 - 32 Hz 9 0 - 16 Hz 8 Hz 0 - 8 Hz 8 - 16 Hz 10 0 - 8 Hz 4 Hz 0 - 4 Hz 4 - 8 Hz 11 0 - 4 Hz 2 Hz 0 - 2 Hz 2 - 4 Hz 12 0 - 2 Hz 1 Hz 0 - 1 Hz 1 - 2 Hz *Only available for 16,384 Hz sampling. NASA Contract NAS5-02099 spase://SMWG/Person/Vassilis.Angelopoulos PrincipalInvestigator spase://SMWG/Person/John.W.Bonnell CoInvestigator spase://SMWG/Person/Robert.E.Ergun CoInvestigator spase://SMWG/Person/Forrest.S.Mozer CoInvestigator spase://SMWG/Person/Alain.Roux CoInvestigator THEMIS website http://themis.ssl.berkeley.edu spase://SMWG/Repository/NASA/GSFC/SPDF/CDAWeb Online Open FTP access to files at SPDF ftp://spdf.gsfc.nasa.gov/pub/data/themis/the/l2/fbk/ NASA/GSFC CDAWeb ftp access to FBK data. HTTP access to files at SPDF http://spdf.gsfc.nasa.gov/pub/data/themis/the/l2/fbk/ In CDF via HTTP from SPDF CDAWeb http://cdaweb.gsfc.nasa.gov THE_L2_FBK Access to ASCII, CDF, and plots via NASA/GSFC CDAWeb CDF xxxx spase://SMWG/Instrument/THEMIS/E/EFI spase://SMWG/Instrument/THEMIS/E/SCM ElectricField MagneticField Spectrum 2007-02-24T00:00:01 -P7D PT4S the_fbh the_fb_hff Peak and average values from the coupled, high-frequency signal off opposing EFI booms 1 and 2. Booms 1 and 2 are situated in the spin plane of the spacecraft, boom 1 along the positive x-axis (SPG coordinates). hf_peak and hf_avg are the peak and average values of the output of the High-Frequency Filter, a broadband filter convering the 100- to 400-kHz band used for AKR detection V 2 FBK-E HF Filter Peak Voltage 1 0.0 1.0E10 NaN FBK-E HF Filter Average Voltage 2 0.0 1.0E10 NaN Potential the_fbh_time the_fb_hff_time the_fbh_time, UTC, in seconds since 01-Jan-1970 00:00:00 Not including leap seconds sec 0.0 5.0E9 NaN Temporal the_fbh_compno the_fb_hff_compno num 2 FBK-E HF Filter Peak Voltage 1 1 2 -32768 FBK-E HF Filter Average Voltage 2 1 2 -32768 Other Calibrated Spectra the_fb_v1 Spectrogram FBK potential, EFI sensor 1 in spacecraft spin plane along the positive x-axis(SPG coordinates). Average of absolute values. V 6 the_fb_v1_1 1 0.0 1.0E10 NaN the_fb_v1_2 2 0.0 1.0E10 NaN the_fb_v1_3 3 0.0 1.0E10 NaN the_fb_v1_4 4 0.0 1.0E10 NaN the_fb_v1_5 5 0.0 1.0E10 NaN the_fb_v1_6 6 0.0 1.0E10 NaN Potential the_fb_v1_time the_fb_v1_time the_fb_v1_time, UTC, in seconds since 01-Jan-1970 00:00:00 Not including leap seconds sec 0.0 5.0E9 NaN Temporal Calibrated Spectra the_fb_v2 Spectrogram FBK potential, EFI sensor 2 in spacecraft spin plane along the negative x-axis (SPG coordinates). Average of absolute values. V 6 the_fb_v2_1 1 0.0 1.0E10 NaN the_fb_v2_2 2 0.0 1.0E10 NaN the_fb_v2_3 3 0.0 1.0E10 NaN the_fb_v2_4 4 0.0 1.0E10 NaN the_fb_v2_5 5 0.0 1.0E10 NaN the_fb_v2_6 6 0.0 1.0E10 NaN Potential the_fb_v2_time the_fb_v2_time the_fb_v2_time, UTC, in seconds since 01-Jan-1970 00:00:00 Not including leap seconds sec 0.0 5.0E9 NaN Temporal Calibrated Spectra the_fb_v3 Spectrogram FBK potential, EFI sensor 3 in spacecraft spin plane along the positive y-axis (SPG coordinates). Average of absolute values. V 6 the_fb_v3_1 1 0.0 1.0E10 NaN the_fb_v3_2 2 0.0 1.0E10 NaN the_fb_v3_3 3 0.0 1.0E10 NaN the_fb_v3_4 4 0.0 1.0E10 NaN the_fb_v3_5 5 0.0 1.0E10 NaN the_fb_v3_6 6 0.0 1.0E10 NaN Potential the_fb_v3_time the_fb_v3_time the_fb_v3_time, UTC, in seconds since 01-Jan-1970 00:00:00 Not including leap seconds sec 0.0 5.0E9 NaN Temporal Calibrated Spectra the_fb_v4 Spectrogram FBK potential, EFI sensor 4 in spacecraft spin plane along the negative y-axis (SPG coordinates). Average of absolute values. V 6 the_fb_v4_1 1 0.0 1.0E10 NaN the_fb_v4_2 2 0.0 1.0E10 NaN the_fb_v4_3 3 0.0 1.0E10 NaN the_fb_v4_4 4 0.0 1.0E10 NaN the_fb_v4_5 5 0.0 1.0E10 NaN the_fb_v4_6 6 0.0 1.0E10 NaN Potential the_fb_v4_time the_fb_v4_time the_fb_v4_time, UTC, in seconds since 01-Jan-1970 00:00:00 Not including leap seconds sec 0.0 5.0E9 NaN Temporal Calibrated Spectra the_fb_v5 Spectrogram FBK potential, EFI sensor 5 located atop spacecraft along the spin axis (positive z-axis) (SPG coordinates). Average of absolute values. V 6 the_fb_v5_1 1 0.0 1.0E10 NaN the_fb_v5_2 2 0.0 1.0E10 NaN the_fb_v5_3 3 0.0 1.0E10 NaN the_fb_v5_4 4 0.0 1.0E10 NaN the_fb_v5_5 5 0.0 1.0E10 NaN the_fb_v5_6 6 0.0 1.0E10 NaN Potential the_fb_v5_time the_fb_v5_time the_fb_v5_time, UTC, in seconds since 01-Jan-1970 00:00:00 Not including leap seconds sec 0.0 5.0E9 NaN Temporal Calibrated Spectra the_fb_v6 Spectrogram FBK potential, EFI sensor 6 located below the spacecraft along the spin axis (negative z-axis) (SPG coordinates). Average of absolute values. V 6 the_fb_v6_1 1 0.0 1.0E10 NaN the_fb_v6_2 2 0.0 1.0E10 NaN the_fb_v6_3 3 0.0 1.0E10 NaN the_fb_v6_4 4 0.0 1.0E10 NaN the_fb_v6_5 5 0.0 1.0E10 NaN the_fb_v6_6 6 0.0 1.0E10 NaN Potential the_fb_v6_time the_fb_v6_time the_fb_v6_time, UTC, in seconds since 01-Jan-1970 00:00:00 Not including leap seconds sec 0.0 5.0E9 NaN Temporal Calibrated Spectra the_fb_edc12 Spectrogram FBK coupled E field DC component, EFI sensors 1 and 2 in the spacecraft spin plane (sensor 1 along positive x-axis, SPG coordinates). Average of absolute values. mV/m 1e-3>V/m 6 the_fb_edc12_1 1 0.0 1.0E10 NaN the_fb_edc12_2 2 0.0 1.0E10 NaN the_fb_edc12_3 3 0.0 1.0E10 NaN the_fb_edc12_4 4 0.0 1.0E10 NaN the_fb_edc12_5 5 0.0 1.0E10 NaN the_fb_edc12_6 6 0.0 1.0E10 NaN Electric the_fb_edc12_time the_fb_edc12_time the_fb_edc12_time, UTC, in seconds since 01-Jan-1970 00:00:00 Not including leap seconds sec 0.0 5.0E9 NaN Temporal Calibrated Spectra the_fb_edc34 Spectrogram FBK coupled E field DC component, EFI sensors 3 and 4 in the spacecraft spin plane (sensor 3 along positive y-axis, SPG coordinates). Average of absolute values. mV/m 1e-3>V/m 6 the_fb_edc34_1 1 0.0 1.0E10 NaN the_fb_edc34_2 2 0.0 1.0E10 NaN the_fb_edc34_3 3 0.0 1.0E10 NaN the_fb_edc34_4 4 0.0 1.0E10 NaN the_fb_edc34_5 5 0.0 1.0E10 NaN the_fb_edc34_6 6 0.0 1.0E10 NaN Electric the_fb_edc34_time the_fb_edc34_time the_fb_edc34_time, UTC, in seconds since 01-Jan-1970 00:00:00 Not including leap seconds sec 0.0 5.0E9 NaN Temporal Calibrated Spectra the_fb_edc56 Spectrogram FBK coupled E field DC component, EFI sensors 5 and 6 (axial, sensor 5 along positve z-axis, SPG coordinates). Average of absolute values. mV/m 1e-3>V/m 6 the_fb_edc56_1 1 0.0 1.0E10 NaN the_fb_edc56_2 2 0.0 1.0E10 NaN the_fb_edc56_3 3 0.0 1.0E10 NaN the_fb_edc56_4 4 0.0 1.0E10 NaN the_fb_edc56_5 5 0.0 1.0E10 NaN the_fb_edc56_6 6 0.0 1.0E10 NaN Electric the_fb_edc56_time the_fb_edc56_time the_fb_edc56_time, UTC, in seconds since 01-Jan-1970 00:00:00 Not including leap seconds sec 0.0 5.0E9 NaN Temporal Calibrated Spectra the_fb_scm1 Spectrogram for FBK Search Coil Magnetometer (SCM) Axis 1. Average of absolute values. SCM axes are specific to the instrument. nT 1e-9>T 6 the_fb_scm1_1 1 0.0 1.0E10 NaN the_fb_scm1_2 2 0.0 1.0E10 NaN the_fb_scm1_3 3 0.0 1.0E10 NaN the_fb_scm1_4 4 0.0 1.0E10 NaN the_fb_scm1_5 5 0.0 1.0E10 NaN the_fb_scm1_6 6 0.0 1.0E10 NaN Magnetic the_fb_scm1_time the_fb_scm1_time the_fb_scm1_time, UTC, in seconds since 01-Jan-1970 00:00:00 Not including leap seconds sec 0.0 5.0E9 NaN Temporal Calibrated Spectra the_fb_scm2 Spectrogram for FBK Search Coil Magnetometer (SCM) Axis 2. Average of absolute values. SCM axes are specific to the instrument. nT 1e-9>T 6 the_fb_scm2_1 1 0.0 1.0E10 NaN the_fb_scm2_2 2 0.0 1.0E10 NaN the_fb_scm2_3 3 0.0 1.0E10 NaN the_fb_scm2_4 4 0.0 1.0E10 NaN the_fb_scm2_5 5 0.0 1.0E10 NaN the_fb_scm2_6 6 0.0 1.0E10 NaN Magnetic the_fb_scm2_time the_fb_scm2_time the_fb_scm2_time, UTC, in seconds since 01-Jan-1970 00:00:00 Not including leap seconds sec 0.0 5.0E9 NaN Temporal Calibrated Spectra the_fb_scm3 Spectrogram for FBK Search Coil Magnetometer (SCM) Axis 3. Average of absolute values. SCM axes are specific to the instrument. nT 1e-9>T 6 the_fb_scm3_1 1 0.0 1.0E10 NaN the_fb_scm3_2 2 0.0 1.0E10 NaN the_fb_scm3_3 3 0.0 1.0E10 NaN the_fb_scm3_4 4 0.0 1.0E10 NaN the_fb_scm3_5 5 0.0 1.0E10 NaN the_fb_scm3_6 6 0.0 1.0E10 NaN Magnetic the_fb_scm3_time the_fb_scm3_time the_fb_scm3_time, UTC, in seconds since 01-Jan-1970 00:00:00 Not including leap seconds sec 0.0 5.0E9 NaN Temporal Calibrated Spectra the_fb_eac12 FBK spectrogram for coupled E field AC component, EFI sensors 1 and 2 (spin plane, sensor 1 along positve x-axis, SPG coordinates). Average of absolute values. mV/m 1e-3>V/m 6 the_fb_eac12_1 1 0.0 1.0E10 NaN the_fb_eac12_2 2 0.0 1.0E10 NaN the_fb_eac12_3 3 0.0 1.0E10 NaN the_fb_eac12_4 4 0.0 1.0E10 NaN the_fb_eac12_5 5 0.0 1.0E10 NaN the_fb_eac12_6 6 0.0 1.0E10 NaN Electric the_fb_eac12_time the_fb_eac12_t ime the_fb_eac12_time, UTC, in seconds since 01-Jan-1970 00:00:00 Not including leap seconds sec 0.0 5.0E9 NaN Temporal Calibrated Spectra the_fb_eac34 FBK spectrogram for coupled E field AC component, EFI sensors 3 and 4 (spin plane, sensor 3 along positive y-axis, SPG coordinates). Average of absolute values. mV/m 1e-3>V/m 6 the_fb_eac34_1 1 0.0 1.0E10 NaN the_fb_eac34_2 2 0.0 1.0E10 NaN the_fb_eac34_3 3 0.0 1.0E10 NaN the_fb_eac34_4 4 0.0 1.0E10 NaN the_fb_eac34_5 5 0.0 1.0E10 NaN the_fb_eac34_6 6 0.0 1.0E10 NaN Electric the_fb_eac34_time the_fb_eac34_time the_fb_eac34_time, UTC, in seconds since 01-Jan-1970 00:00:00 Not including leap seconds sec 0.0 5.0E9 NaN Temporal Calibrated Spectra the_fb_eac56 FBK spectrogram for coupled E field AC component, EFI sensors 5 and 6 (axial, sensor 5 along positive z-axis, SPG coordinates). Average of absolute values. mV/m 1e-3>V/m 6 the_fb_eac56_1 1 0.0 1.0E10 NaN the_fb_eac56_2 2 0.0 1.0E10 NaN the_fb_eac56_3 3 0.0 1.0E10 NaN the_fb_eac56_4 4 0.0 1.0E10 NaN the_fb_eac56_5 5 0.0 1.0E10 NaN the_fb_eac56_6 6 0.0 1.0E10 NaN Electric the_fb_eac56_time the_fb_eac56_time the_fb_eac56_time, UTC, in seconds since 01-Jan-1970 00:00:00 Not including leap seconds sec 0.0 5.0E9 NaN Temporal the_fb_yaxis the_fb_yaxis the_fb_yaxis Hz 6 the_fb_yaxis_1 1 0.0 10000.0 NaN the_fb_yaxis_2 2 0.0 10000.0 NaN the_fb_yaxis_3 3 0.0 10000.0 NaN the_fb_yaxis_4 4 0.0 10000.0 NaN the_fb_yaxis_5 5 0.0 10000.0 NaN the_fb_yaxis_6 6 0.0 10000.0 NaN Temporal the_fbk_fstart the_fbk_fstart the_fbk_fstart Hz 6 the_fbk_fstart_1 1 0.0 1000000.0 NaN the_fbk_fstart_2 2 0.0 1000000.0 NaN the_fbk_fstart_3 3 0.0 1000000.0 NaN the_fbk_fstart_4 4 0.0 1000000.0 NaN the_fbk_fstart_5 5 0.0 1000000.0 NaN the_fbk_fstart_6 6 0.0 1000000.0 NaN Temporal the_fbk_fband the_fbk_fband Graph Y-Axis, Frequency Hz 6 the_fbk_fband_1 1 0.0 1000000.0 NaN the_fbk_fband_2 2 0.0 1000000.0 NaN the_fbk_fband_3 3 0.0 1000000.0 NaN the_fbk_fband_4 4 0.0 1000000.0 NaN the_fbk_fband_5 5 0.0 1000000.0 NaN the_fbk_fband_6 6 0.0 1000000.0 NaN Temporal