On Board Fast Fourier Transform (FFT) power spectra of Electric (EFI) and Magnetic (SCM) field measurements for particle and wave burst survey modes. Spectra are produced only in Particle Burst and Wave Burst modes; only a preselected four of the signals listed in Table 1 are input at any time. Data fed through the FFT while not in Particle or Wave Burst modes is automatically disgarded. The FFTs (Cooley-Tukey algorithm) are conducted as an integral part of the power spectrum calculation by the Field Programable Gate Arrays (FPGAs). A CORDIC algorithm is used for sine/cosine calculations. The data has raw resolution of 1024 pts for 8,192 sample/sec signals and 2048 pts for 16,384 sample/sec signals (EAC measurements only). Signals at 8,192 samples/sec are handled by 1024-point FFTs, while those at 16,384 samples/sec go through 2048-point FFTs. Past and current signal configurations for specific spacecraft are listed bellow in Table 2. The spectra are arranged into log spaced frequency bins in steps of 16, 32, or 64. Cadence is adjusted to keep packet size constant (i.e. increasing the fequency resolution by a factor of 2 decreases the sampling rate by 1/2). The frequency bins cover a range of 0 Hz to 4 kHz.
Table 1: FFT Input Signals.
Signal Description
SCMX, SCMY, SCMZ: Three axis magnetic fiend from SCM
V1 through V6: Probe-spacecraft voltage for all six EFI sensors
E12DC, E34DC, E56DC: DC-coupled electric field measured from opposing EFI sensors
E12AC, E34AV, E56AC: AC-coupled electric field measured from opposing EFI sensors
E12HF: High frequency electric field from EFI
Table 2: Spacecraft specific configurations.
All probes were initially set to use EDC34, EDC56, SCM2, and SCM3 signals for both particle and wave burst modes. Output was set to 16 frequency bins at 4 Hz. Configuration Changes:
30 June - 3 July 2008: Particle burst spectra on all probes reconfigured to 64 bins at 1 Hz.
Table 3: Instrument-Spacecraft Physical Configuration
Instrument Alignment in Spacecraft Geometric coordinates (SPG). See THEMIS website for coordinate system details and mechanical drawings.
EFI boom 1: Along positive X-axis
EFI boom 2: Along negative X-axis
EFI boom 3: Along positive Y-axis
EFI boom 4: Along negative Y-axis
EFI boom 5: Along positive Z-axis
EFI boom 6: Along negative Z-axis
SCM: *The SCM uses an instrument specific set of axes; an orthogonal system centered instrument with the X-axis 12.1 degrees from the SPG X-axis.Version:2.2.9
On Board Fast Fourier Transform (FFT) power spectra of Electric (EFI) and Magnetic (SCM) field measurements for particle and wave burst survey modes. Spectra are produced only in Particle Burst and Wave Burst modes; only a preselected four of the signals listed in Table 1 are input at any time. Data fed through the FFT while not in Particle or Wave Burst modes is automatically disgarded. The FFTs (Cooley-Tukey algorithm) are conducted as an integral part of the power spectrum calculation by the Field Programable Gate Arrays (FPGAs). A CORDIC algorithm is used for sine/cosine calculations. The data has raw resolution of 1024 pts for 8,192 sample/sec signals and 2048 pts for 16,384 sample/sec signals (EAC measurements only). Signals at 8,192 samples/sec are handled by 1024-point FFTs, while those at 16,384 samples/sec go through 2048-point FFTs. Past and current signal configurations for specific spacecraft are listed bellow in Table 2. The spectra are arranged into log spaced frequency bins in steps of 16, 32, or 64. Cadence is adjusted to keep packet size constant (i.e. increasing the fequency resolution by a factor of 2 decreases the sampling rate by 1/2). The frequency bins cover a range of 0 Hz to 4 kHz.
Table 1: FFT Input Signals.
Signal Description
SCMX, SCMY, SCMZ: Three axis magnetic fiend from SCM
V1 through V6: Probe-spacecraft voltage for all six EFI sensors
E12DC, E34DC, E56DC: DC-coupled electric field measured from opposing EFI sensors
E12AC, E34AV, E56AC: AC-coupled electric field measured from opposing EFI sensors
E12HF: High frequency electric field from EFI
Table 2: Spacecraft specific configurations.
All probes were initially set to use EDC34, EDC56, SCM2, and SCM3 signals for both particle and wave burst modes. Output was set to 16 frequency bins at 4 Hz. Configuration Changes:
30 June - 3 July 2008: Particle burst spectra on all probes reconfigured to 64 bins at 1 Hz.
Table 3: Instrument-Spacecraft Physical Configuration
Instrument Alignment in Spacecraft Geometric coordinates (SPG). See THEMIS website for coordinate system details and mechanical drawings.
EFI boom 1: Along positive X-axis
EFI boom 2: Along negative X-axis
EFI boom 3: Along positive Y-axis
EFI boom 4: Along negative Y-axis
EFI boom 5: Along positive Z-axis
EFI boom 6: Along negative Z-axis
SCM: *The SCM uses an instrument specific set of axes; an orthogonal system centered instrument with the X-axis 12.1 degrees from the SPG X-axis.| Role | Person | |
|---|---|---|
| 1. | PrincipalInvestigator | spase://SMWG/Person/Vassilis.Angelopoulos |
| 2. | CoInvestigator | spase://SMWG/Person/John.W.Bonnell |
| 3. | CoInvestigator | spase://SMWG/Person/C.M.Cully |
| 4. | CoInvestigator | spase://SMWG/Person/Alain.Roux |
| 5. | CoInvestigator | spase://SMWG/Person/Robert.E.Ergun |
NASA/GSFC CDAWeb ftp access to FFT data.
In CDF via HTTP from SPDF
Access to ASCII, CDF, and plots via NASA/GSFC CDAWeb
FFT Power Spectrum in Particle Burst mode, 16 frequencies for SCM delta-B (parallel to B)
FFT Power Spectrum in Particle Burst, 16 frequencies for SCM delta-B (perp to B)
FFT Power Spectrum in Particle Burst, 16 frequencies for E Field AC Component, Sensors 1 and 2 (spin plane)
FFT Power Spectrum in Particle Burst, 16 frequencies for E Field AC Component, Sensors 3 and 4 (spin plane)
FFT Power Spectrum in Particle Burst, 16 frequencies for E Field AC Component, Sensors 5 and 6 (axial)
FFT Power Spectrum in Particle Burst, 16 frequencies for E Field DC Component, Sensors 1 and 2 (spin plane)
FFT Power Spectrum in Particle Burst, 16 frequencies for E Field DC Component, Sensors 3 and 4 (spin plane)
FFT Power Spectrum in Particle Burst, 16 frequencies for E Field DC Component, Sensors 5 and 6 (axial)
FFT Power Spectrum in Particle Burst, 16 frequencies for EFI E (parallel to B)
FFT Power Spectrum in Particle Burst, 16 frequencies for EFI E (perp to B)
FFT Power Spectrum in Particle Burst, 16 frequenci es for SCM, Axis 1
FFT Power Spectrum in Particle Burst, 16 frequencies for SCM, Axis 1
FFT Power Spectrum in Particle Burst, 16 frequencies for SCM, Axis 1
FFT Power Spectrum in Particle Burst, 16 frequencies for EFI Potential, Sensor 1
FFT Power Spectrum in Particle Burst, 16 frequencies for EFI Potential, Sensor 2
FFT Power Spectrum in Particle Burst, 16 frequencies for EFI Potential, Sensor 3
FFT Power Spectrum in Particle Burst, 16 frequencies for EFI Potential, Sensor 4
FFT Power Spectrum in Particle Burst, 16 frequencies for EFI Potential, Sensor 5
FFT Power Spectrum in Particle Burst, 16 frequencies for EFI Potential, Sensor 6
thc_ffp_16_yaxis
thc_ffp_16_time, UTC, in seconds since 01-Jan-1970 00:00:00
EPOCH0 of THEMIS time base
thc_ffp_16_epoch
FFT Power Spectr um in Particle Burst, 32 frequencies for SCM delta-B (parallel to B)
FFT Power Spectrum in Particle Burst, 32 frequencies for SCM delta-B (perp to B)
FFT Power Spectrum in Particle Burst, 32 frequencies for E Field AC Component, Sensors 1 and 2 (spin plane)
FFT Power Spectrum in Particle Burst, 32 frequencies for E Field AC Component, Sensors 3 and 4 (spin plane)
FFT Power Spectrum in Particle Burst, 32 frequencies for E Field AC Component, Sensors 5 and 6 (axial)
FFT Power Spectrum in Particle Burst, 32 frequencies for E Field DC Component, Sensors 1 and 2 (spin plane)
FFT Power Spectrum in Particle Burst, 32 frequencies for E Field DC Component, Sensors 3 and 4 (spin plane)
FFT Power Spectrum in Particle Burst, 32 frequencies for E Field DC Component, Sensors 5 and 6 (axial)
FFT Power Spectrum in Particle Burst, 32 frequencies for EFI E (parallel to B)
FFT Power Spectrum in Particle Burst, 32 frequencies for EFI E (perp to B)
FFT Power Spectrum in Particle Burst, 32 frequencies for SCM, Axis 1
FFT Power Spectrum in Particle Burst, 32 frequencies for SCM, Axis 1
FFT Power Spectrum in Particle Burst, 32 frequencies for SCM, Axis 1
FFT Power Spectrum in Particle Burst, 32 frequencies for EFI Potential, Sensor 1
FFT Power Spectrum in Particle Burst, 32 frequencies for EFI Potential, Sensor 2
FFT Power Spectrum in Particle Burst, 32 frequencies for EFI Potential, Sensor 3
FFT Power S pectrum in Particle Burst, 32 frequencies for EFI Potential, Sensor 4
FFT Power Spectrum in Particle Burst, 32 frequencies for EFI Potential, Sensor 5
FFT Power Spectrum in Particle Burst, 32 frequencies for EFI Potential, Sensor 6
thc_ffp_32_yaxis
thc_ffp_32_time, UTC, in seconds since 01-Jan-1970 00:00:00
EPOCH0 of THEMIS time base
thc_ffp_32_epoch
FFT Power Spectrum in Particle Burst, 64 frequencies for SCM delta-B (parallel to B)
FFT Power Spectrum in Particle Burst, 64 frequencies for SCM delta-B (perp to B)
FFT Power Spectrum in Particle Burst, 64 frequencies for E Field AC Component, Sensors 1 and 2 (spin plane).
FFT Power Spectrum in Particle Burst, 64 frequencies for E Field AC Component, Sensors 3 and 4 (spin plane)
FFT Power Spectrum in Particle Burst, 64 frequencies for E Field AC Component, Sensors 5 and 6 (axial)
FFT Power Spectrum in Particle Burst, 64 frequencies for E Field DC Component, Sensors 1 and 2 (spin plane)
FFT Power Spectrum in Particle Burst, 64 frequencies for E Field DC Component, Sensors 3 and 4 (spin plane)
FFT Power Spectrum in Particle Burst, 64 frequencies for E Field DC Component, Sensors 5 and 6 (axial)
FFT Power Spectrum in Particle Burst, 64 frequencies for EFI E (parallel to B)
FFT Power Spectrum in Particle Burst, 64 frequencies for EFI E (perp to B)
FFT Power Spectrum in Particle Burst, 64 frequencies for SCM, Axis 1
FFT Power Spectrum in Particle Burst, 64 frequencies for SCM, Axis 1
FFT Power Spectrum in Particle Burst, 64 frequencies for SCM, Axis 1
FFT Power Spectrum in Particle Burst, 64 frequencies for EFI Potential, Sensor 1
FFT P ower Spectrum in Particle Burst, 64 frequencies for EFI Potential, Sensor 2
FFT Power Spectrum in Particle Burst, 64 frequencies for EFI Potential, Sensor 3
FFT Power Spectrum in Particle Burst, 64 frequencies for EFI Potential, Sensor 4
FFT Power Spectrum in Particle Burst, 64 frequencies for EFI Potential, Sensor 5
FFT Power Spectrum in Particle Burst, 64 frequencies for EFI Potential, Sensor 6
thc_ffp_64_yaxis
thc_ffp_64_time, UTC, in seconds since 01-Jan-1970 00:00:00
EPOCH0 of THEMIS time base
thc_ffp_64_epoch
FFT Power Spectrum in Wave Burst, 16 frequencies for SCM delta-B (parallel to B)
FFT Power Spectrum in Wave Burst, 16 frequencies for SCM delta-B (perp to B)
FFT Power Spectrum in Wave Burst, 16 frequencies for E Field AC Component, Sensors 1 and 2 (spin plane)
FFT Power Spectrum in Wave Burst, 16 frequencies for E Field AC Component, Sensors 3 and 4 (spin plane)
FFT Power Spectrum in Wave Burst, 16 frequencies for E Field AC Component, Sensors 5 and 6 (axial)
FFT Power Spectrum in Wave Burst, 16 frequencies for E Field DC Component, Sensors 1 and 2 (spin plane)
FFT Power Spectrum in Wave Burst, 16 frequencies for E Field DC Component, Sensors 3 and 4 (spin plane)
FFT Power Spectrum in Wave Burst, 16 frequencies for E Field DC Component, Sensors 5 and 6 (axial)
FFT Power Spectrum in Wave Burst, 16 frequencies for EFI E (paral lel to B)
FFT Power Spectrum in Wave Burst, 16 frequencies for EFI E (perp to B)
FFT Power Spectrum in Wave Burst, 16 frequencies for SCM, Axis 1
FFT Power Spectrum in Wave Burst, 16 frequencies for SCM, Axis 1
FFT Power Spectrum in Wave Burst, 16 frequencies for SCM, Axis 1
FFT Power Spectrum in Wave Burst, 16 frequencies for EFI Potential, Sensor 1
FFT Power Spectrum in Wave Burst, 16 frequencies for EFI Potential, Sensor 2
FFT Power Spectrum in Wave Burst, 16 frequencies for EFI Potential, Sensor 3
FFT Power Spectrum in Wave Burst, 16 frequencies for EFI Potential, Sensor 4
FFT Power Spectrum in Wave Burst, 16 frequencies for EFI Potential, Sensor 5
FFT Power Spectrum in Wave Burst, 16 frequencies for EFI Potential, Sensor 6
thc_ffw_16_yaxis
thc_ffw_16_time, UTC, in seconds since 01-Jan-1970 00:00:00
EPOCH0 of THEMIS time base
thc_ffw_16_epoch
FFT Power Spectrum in Wave Burst, 32 frequencies for SCM delta-B (parallel to B)
FFT Power Spectrum in Wave Burst, 32 frequencies for SCM delta-B (perp to B)
FFT Power Spectrum in Wave Burst, 32 frequencies for E Field AC Component, Sensors 1 and 2 (spin plane)
FFT Power Spectrum in Wave Burst, 32 frequencies for E Field AC Component, Sensors 3 and 4 (spin plane)
FFT Power Spectrum in Wave Burst, 32 frequencies for E Field AC Component, Sensors 5 and 6 (axial)
FFT Power Spectrum in Wave Burst, 32 frequencies for E Field DC Component, Sensors 1 and 2 (spin plane)
FFT Power Spectrum in Wave Burst, 32 frequencies for E Field DC Component, Sensors 3 and 4 (spin plane)
FFT Power Spectrum in Wave Burst, 32 frequencies for E Field DC Component, Sensors 5 and 6 (axial)
FFT Power Spectrum in Wave Burst, 32 frequencies for EFI E (parallel to B)
FFT Power Spectrum in Wave Burst, 32 frequencies for EFI E (perp to B)
FFT Power Spectrum in Wave Burst, 32 frequencies for SCM, Axis 1
FFT Power Spectrum in Wave Burst, 32 frequencies for SCM, Axis 1
FFT Power Spectrum in Wave Burst, 32 frequencies for SCM, Axis 1
FFT Power Spectrum in Wave Burst, 32 frequencies for EFI Potential, Sensor 1
FFT Power Spectrum in Wave Burst, 32 frequencies for EFI Potential, Sensor 2
FFT Power Spectrum in Wave Burst, 32 frequencies for EFI Potential, Sensor 3
FFT Power Spectrum in Wave Burst, 32 frequencies for EFI Potential, Sensor 4
FFT Power Spectrum in Wave Burst, 32 frequencies for EFI Potential, Sensor 5
FFT Power Spectrum in Wave Burst, 32 frequencies for EFI Potential, Sensor 6
thc_ffw_32_yaxis
thc_ffw_32_time, UTC, in seconds since 01-Jan-1970 00:00:00
EPOCH0 of THEMIS time base
thc_ffw_32_epoch
FFT Power Spectrum in Wave Burst, 64 frequencies for SCM delta-B (parallel to B)
FFT Power Spectrum in Wave Burst, 64 frequencies for SCM delta-B (perp to B)
FFT Power Spectrum in Wave Burst, 64 frequencies for E Field AC Component, Sensors 1 and 2 (spin plane)
FFT Power Spectrum in Wave Burst, 64 frequencies for E Field AC Component, Sensors 3 and 4 (spin plane)
FFT Power Spectrum in Wave Burst, 64 frequencies for E Field AC Component, Sensors 5 and 6 (axial)
FFT Power Spectrum in Wave Burst, 64 frequencies for E Field DC Component, Sensors 1 and 2 (spin plane)
FFT Power Spectrum in Wave Burst, 64 frequencies for E Field DC Component, Sensors 3 and 4 (spin plane)
FFT Power Spectrum in Wave Burst, 64 frequencies for E Field DC Component, Sensors 5 and 6 (axial)
FFT Power Spectrum in Wave Burst, 64 frequencies for EFI E (parallel to B)
FFT Power Spectrum in Wave Burst, 64 frequencies for EFI E (perp to B)
FFT Power Spectrum in Wave Burst, 64 frequencies for SCM, Axis 1
FFT Power Spectrum in Wave Burst, 64 frequencies for SCM, Axis 1
FFT Power Spectrum in Wave Burst, 64 frequencies for SCM, Axis 1
FFT Power Spectrum in Wave Burst, 64 frequencies for EFI Potential, Sensor 1
FFT Power Spectrum in Wave Burst, 64 frequencies for EFI Potential, Sensor 2
FFT Power Spectrum in Wave Burst, 64 frequencies for EFI Potential, Sensor 3
FFT Power Spectrum in Wave Burst, 64 frequencies for EFI Potential, Sensor 4
FFT Power Spectrum in Wave Burst, 64 frequencies for EFI Potential, Sensor 5
FFT Power Spectrum in Wave Burst, 64 frequencies for EFI Potential, Sensor 6
thc_ffw_64_yaxis
thc_ffw_64_time, UTC, in seconds since 01-Jan-1970 00:00:00
EPOCH0 of THEMIS time base
thc_ffw_64_epoch
range_epoch