FAST Electrostatic Analyzer (ESA), Electron Survey 0.625 s Data

https://doi.org/10.48322/0ydx-j139

2023-07-30 12:34:56.789

The FAST IES and EES measure 32 pitch angle directions simultaneously, 11.25° resolution, and sweep over 48 energy steps in 1/64 of a spacecraft spin. The energy range is nominally 3 eV to 25 keV for ions and 4 eV to 30 keV for electrons, respectively. Each spectrometer consists of two half sensor heads each with 180° by 10° field-of-view, FOV, that are mounted on opposite sides of the spacecraft to form a 360° planar FOV. The out-of-plane response is roughly Gaussian with a full width, half maximum, FWHM, of about 5°. The planar FOV is within the spacecraft spin plane, which is oriented with the spin vector normal to the nominal magnetic field direction. This orientation facilitates continuous pitch angle measurements. Deflectors are used to steer the sensor FOV out of this plane by up to 10° to account for variations of the magnetic field direction during the orbit. In general, the pitch angle distribution always includes both the parallel and Anti-parallel magnetic field directions. Burst data consists of a 32 angle by 48 anergy bin array of counts. Counts are pseudo-log compressed from 16 to 8 bits onboard. The first energy step is a high voltage retrace and should be ignored. Detector anodes rotate by half an anode or 5.625° each sweep. Survey data is averaged burst data that has been despun onboard. Slow survey is averaged into a 32 angle by 48 energy array each half spin or about 2.5 s. Some blurring of the angular resolution results from the half anode rotation on alternate sweeps. Fast survey is averaged into a 64 angle by 48 energy array that maintains the angular resolution. Fast survey time resolution varies from 1/16 to 1/4 of a spin.

J.P. McFadden

spase://VSPO/NumericalData/FAST/EES/L2/PT5S

spase://VSPO/NumericalData/FAST/ESA/L2/Electron/Survey/PT0.625S

Online

Open

CDF

None

J.P. McFadden. Please acknowledge the data providers and CDAWeb when using these data.

Online

Open

CSV

J.P. McFadden. Please acknowledge the data providers and CDAWeb when using these data.

PT0.625S

CDF Epoch

Time series defined by using: EPOCH

epoch

CDF Epoch Time, one Element per Ion Distribution

None This parameter exhibits an increasing monotonic progression.

PT0.625S

s

21-Aug-1996 00:00:00.000

01-May-2009 00:00:00.000

31-Dec-9999 23:59:59.999

UNIX Time

Time series defined by using: EPOCH

time_unix

UNIX Time, Elapsed Seconds since 1970-01-01 for each Data Record, without Leap Second Correction, one Element per Distribution, this Time is the Center Time of Data Collection

None This parameter exhibits an increasing monotonic progression.

PT0.625S

s

8.40586e+08

1.24114e+09

-1.0e+31

Interval Start Time, UNIX

Time series defined by using: EPOCH

time_start

UNIX Time at the Start of Data Collection

None This parameter exhibits an increasing monotonic progression.

PT0.625S

s

8.40586e+08

1.24114e+09

-1.0e+31

Interval End Time, UNIX

Time series defined by using: EPOCH

time_end

UNIX Time at the End of Data Collection

None This parameter exhibits an increasing monotonic progression.

PT0.625S

s

8.40586e+08

1.24114e+09

-1.0e+31

Averaging Time

Time series defined by using: EPOCH

time_delta

Averaging Time, Time End minus Time Start

None

PT0.625S

s

-1.0e+31

1.0e+31

-1.0e+31

Integration Time

Time series defined by using: EPOCH

time_integ

Integration Time, TIME_DELTA/NENERGY

None

PT0.625S

s

-1.0e+31

1.0e+31

-1.0e+31

Header

Time series defined by using: EPOCH

header_bytes

Packet Header Byte Array

None

PT0.625S

0

255

255

Valid Flag

Time series defined by using: EPOCH

valid

Validity Flag Code: Bit 0, Non-Zero Values are not necessarily Valid

None

PT0.625S

-32767

32767

-32768

Quality Flag

Time series defined by using: EPOCH

data_quality

Quality Flag

None

PT0.625S

0

255

255

Number of Angular Bins

Time series defined by using: EPOCH

nbins

Number of Angular Bins

None

PT0.625S

0

255

255

Number of Energies

Time series defined by using: EPOCH

nenergy

Number of Energies

None

PT0.625S

eV

1.60218e-19>J

0

255

255

Geometric Factor

Time series defined by using: EPOCH

geom_factor

Geometric Factor, used in Calibration

None

PT0.625S

-1.0e+31

1.0e+31

-1.0e+31

Geometric Factor Index

Time series defined by using: EPOCH

gf_ind

Geometric Factor Index

None

PT0.625S

-32767

32767

-32768

Bins Index

Time series defined by using: EPOCH

bins_ind

Bins Index for the Number of Angular Bins

None

PT0.625S

-32767

32767

-32768

Mode Index

Time series defined by using: EPOCH

mode_ind

Mode Index for the Data Mode: 0-2=Burst Data, 0-1=Survey Data

None

PT0.625S

0

255

255

Angular Shift, Theta Bin to Pitch Angle

Time series defined by using: EPOCH

theta_shift

Angular Shift, converts Theta Bin Values to Pitch Angles

None

PT0.625S

°

0.0174532925>rad

-400.0

400.0

-1.0e+31

Angular Maximum

Time series defined by using: EPOCH

theta_max

Angular Maximum

None

PT0.625S

°

0.0174532925>rad

-400.0

400.0

-1.0e+31

Angular Minimum

Time series defined by using: EPOCH

theta_min

Angular Minimum

None

PT0.625S

°

0.0174532925>rad

-400.0

400.0

-1.0e+31

Background Counts

Time series defined by using: EPOCH

bkg

Background Counts

None

PT0.625S

-1.0e+31

1.0e+31

-1.0e+31

Spacecraft Potential

Time series defined by using: EPOCH

sc_pot

Spacecraft Potential

None

PT0.625S

V

-1.0e+31

1.0e+31

-1.0e+31

Survey Electron Raw Counts

Time series defined by using: EPOCH

data

Survey Electron Raw Counts Array with Dimension 96⨯64⨯NUM_DISTS

None

PT0.625S

255

Survey Electron Energy Flux

Time series defined by using: EPOCH

eflux

Survey Electron Energy Flux Array with Dimension 96⨯64⨯NUM_DISTS, as Plasmagrams

None

PT0.625S

eV/sr/s

1.60218e-13>J/sr/s

-1.0e+31

Survey Electron Energy Flux, Movie

Time series defined by using: EPOCH

eflux_movie

Survey Electron Energy Flux Array with Dimension 96⨯64⨯NUM_DISTS, as Plasmagram Movies

None This parameter is virtual. It is calculated by calling the function ALTERNATE_VIEW with the following input parameters: eflux.

PT0.625S

eV/sr/s

1.60218e-13>J/sr/s

-1.0e+31

Survey Electron Energy Flux, by Energy by Angle

Time series defined by using: EPOCH

eflux_byE_atA

Survey Electron Energy Flux Array with Dimension 96⨯64⨯NUM_DISTS, as Spectrograms by Energy at Sample Pitch Angle Bin Numbers of varying Pitch Angle

This parameter is virtual. It is calculated by calling the function ALTERNATE_VIEW with the following input parameters: eflux.

PT0.625S

eV/sr/s

1.60218e-13>J/sr/s

-1.0e+31

Survey Electron Energy Flux, by Angle by Energy

Time series defined by using: EPOCH

eflux_byA_atE

Survey Electron Energy Flux Array with Dimension 96⨯64⨯NUM_DISTS, as Spectrograms by Pitch Angle Bin Numbers of varying Pitch Angle at Sample Energies

This parameter is virtual. It is calculated by calling the function ALTERNATE_VIEW with the following input parameters: eflux.

PT0.625S

eV/sr/s

1.60218e-13>J/sr/s

-1.0e+31

Median Pitch Angle

Time series defined by using: EPOCH

pitch_angle_median

Median Pitch Angle

None This parameter is virtual. It is calculated by calling the function ARR_SLICE with the following input parameters: pitch_angle.

PT0.625S

°

0.0174532925>rad

-360.0

360.0

-1.0e+31

Median Energy

Time series defined by using: EPOCH

energy_median

Median Energy

None This parameter is virtual. It is calculated by calling the function ARR_SLICE with the following input parameters: energy_full.

PT0.625S

eV

1.60218e-19>J

0.0

200000.0

-1.0e+31

Energy for Full Distribution

Time series defined by using: EPOCH

energy_full

Energy Values for each Distribution 96⨯64⨯NUM_DISTS

None

PT0.625S

eV

1.60218e-19>J

-1.0e+31

Energy Bin Size for Full Distribution

Time series defined by using: EPOCH

denergy_full

Energy Bin Size for each Distribution 96⨯64⨯NUM_DISTS

None

PT0.625S

eV

1.60218e-19>J

-1.0e+31

Pitch Angle

Time series defined by using: EPOCH

pitch_angle

Pitch Angle Values for each Distribution 96⨯64⨯NUM_DISTS

None

PT0.625S

°

0.0174532925>rad

-1.0e+31

Solid Angle, Domega

Time series defined by using: EPOCH

domega

Solid Angle, Domega, for each Distribution 96⨯64⨯NUM_DISTS

None

PT0.625S

sr

-1.0e+31

Orbit Number

Time series defined by using: ORBIT_NUMBER_EPOCH

orbit_number

Orbit Number for this File, does not Change, so only two Entries per File

None

PT0.625S

-2147483647

2147483647

-2147483648

Orbit Number Time

Time series defined by using: ORBIT_NUMBER_EPOCH

orbit_number_time

Time Array, UNIX Time for Orbit Number

None This parameter exhibits an increasing monotonic progression.

PT0.625S

s

8.40586e+08

1.24114e+09

-1.0e+31

Orbit Number Epoch

Time series defined by using: ORBIT_NUMBER_EPOCH

orbit_number_epoch

CDF Epoch Array for Orbit Number

None This parameter exhibits an increasing monotonic progression.

PT0.625S

s

21-Aug-1996 00:00:00.000

01-May-2009 00:00:00.000

31-Dec-9999 23:59:59.999

Component Numbers for Energy Bins

compno_96

Component Numbers for Energy Bin Array

PT0.625S

0

255

0

Component Numbers for Pitch Angle Bins

compno_64

Component Numbers for Pitch Angle Bin Array

PT0.625S

0

255

0