DMSP F18 Special Sensors-Ions, Electrons, and Scintillation (SSIES) Thermal Plasma Analysis Package, Level 2 (L2), 1 s Data in CDF Format

https://doi.org/10.48322/cxc3-w323

2024-05-03 00:00:00.00

The Special Sensors-Ions, Electrons, and Scintillation (SSIES) thermal plasma analysis package is a suite of instruments built by the Center for Space Sciences at the University of Texas at Dallas and flown on a number of the DMSP satellites. SSIESS includes a Retarding Potential Analyzer (RPA), Ion Drift meter (IDM), scintillation meter, and Langmuir probe.

We gratefully acknowledge the University of Texas Dallas, Center for Space Sciences and the US Air Force for providing the DMSP thermal plasma data

Online

Open

CDF

None

We gratefully acknowledge the University of Texas Dallas, Center for Space Sciences and the US Air Force for providing the DMSP thermal plasma data

Online

Open

CSV

PT1S

Epoch

Epoch

Default time

This Parameter exhibits an increasing Monotonic Progression

01-Jan-1990 00:00:00.000

31-Dec-2029 23:59:59.999

31-Dec-9999 23:59:59.999

vx

Time series defined by using: Epoch

vx

Vx - median filtered and smoothed ion flow in the ram direction

median filtered and smoothed ion flow in the ram direction from the fits to the RPA curve

PT1S

m/s

-2000.0

2000.0

-999999.0

quality flag for Vx data

Time series defined by using: Epoch

vxqual

"Vx quality flag:1,6-good;2,7-fair;else warn [READ QUALITY FLAG Document]"

1-good 2-fair 3-caution 4-bad 5-uncertain

PT1S

1

5

vx rms

Time series defined by using: Epoch

vxrms

Vx root mean square of the RPA fit

root mean square of the fit to the RPA curve giving an indication of the quality of the RPA data for this sweep

PT1S

0.0

999.0

-999999.0

Vx flow

Time series defined by using: Epoch

vxraw

Vx - original unfiltered Vx flow

the unfiltered Vx flow values calculated by the RPA fitting routine

PT1S

m/s

-2000.0

2000.0

-999999.0

vy

Time series defined by using: Epoch

vy

Vy - ion flow in the horizontal crosstrack direction

crosstrack horizontal ion flow from IDM, positive is in the sunward direction regardless of the orientation of the orbit, data taken in two modes: normal and slow (see nmbpts)

PT1S

m/s

-2000.0

2000.0

-999999.0

quality flag for Vy data

Time series defined by using: Epoch

vyqual

"Quality flag for Vy data:1,6-good;2,7-fair;else warn [READ QUALITY FLAG Document]"

1-good 2-fair 3-caution 4-bad 5-uncertain 6-good (F17) 7-fair (F17) 8-caution (F17) 9-caution (sun glint or high-energy particles)

PT1S

1

9

vy rms

Time series defined by using: Epoch

vyrms

Standard deviation of the Vy flow

standard deviation of the six Vy samples taken per second in the normal mode, fill data in slow mode

PT1S

m/s

0.0

2800.0

-999999.0

roughness Vy

Time series defined by using: Epoch

dmhrough

Roughness parameter of Vy

roughness parameter of Vy defined as (delta Vy / averaged Vy)

PT1S

0.0

1.0

-999999.0

vz

Time series defined by using: Epoch

vz

Vz - ion flow in the vertical crosstrack direction

crosstrack vertical ion flow from IDM, positive is in the upward direction, data taken in two modes: normal and slow (see nmbpts)

PT1S

m/s

-2000.0

2000.0

-999999.0

quality flag for Vz data

Time series defined by using: Epoch

vzqual

"Quality flag for Vz data:1,6-good;2,7-fair;else warn [READ QUALITY FLAG Document]"

1-good 2-fair 3-caution 4-bad 5-uncertain 6-good (F17) 7-fair (F17) 8-caution (F17) 9-caution (sun glint or high-energy particles)

PT1S

1

9

stdev vz rms

Time series defined by using: Epoch

vzrms

Standard deviation of the Vz flow

standard deviation of the six Vz samples taken per second in the normal mode, fill data in slow mode

PT1S

m/s

0.0

2800.0

-999999.0

roughness Vz

Time series defined by using: Epoch

dmvrough

Roughness parameter of Vz (delta Vz / averaged Vz)

roughness parameter of Vy defined as (delta Vy / averaged Vy)

PT1S

0.0

1.0

-999999.0

ion temperature

Time series defined by using: Epoch

temp

Ion temperature

temperature of the ions in the plasma calculated from the fit to the RPA curve

PT1S

°K

500.0

20000.0

-999999.0

Quality flag for the ion temperature

Time series defined by using: Epoch

tempqual

"Quality flag for the ion temperature:1,6-good;2,7-fair;else warn [READ QUALITY FLAG Document]"

1-good 2-fair 3-caution 4-bad 5-uncertain

PT1S

1

5

electron temperature

Time series defined by using: Epoch

te

Electron temperature

the electron temperature based on an onboard calculation of the Langmuir probe sweep which occurs once every 4 s

PT1S

°K

500.0

10000.0

-999999.0

ion density

Time series defined by using: Epoch

dens

Ni calculated from the RPA

Ion density of the plasma calculated from the fit to the RPA curve

PT1S

cm^-3

1.0e6>m^-3

0.0

1.0e+08

-999999.0

density quality flag

Time series defined by using: Epoch

densqual

"Quality flag for the ion density:1,6-good;2,7-fair;else warn [READ QUALITY FLAG Document]"

1-good 2-fair 3-caution 4-bad 5-uncertain

PT1S

1

5

ion density scint meter

Time series defined by using: Epoch

ductdens

Ni from scintillation meter

the average of the 24 Hz samples of the ion density by the scintillation meter, because of its large aperture this is considered the best meaure of the ion density

PT1S

cm^-3

1.0e6>m^-3

0.0

1.0e+08

-999999.0

roughness SM den

Time series defined by using: Epoch

ductdensrough

Roughness parameter of SM density

roughness parameter of scintillation meter ion density defined as (delta Ni/ averaged Ni)

PT1S

0.0

1.0

-999999.0

ion density RPA 0 volts

Time series defined by using: Epoch

dens0v

Ni measured from the RPA at 0 volts

during each RPA sweep there is a point where the repeller voltage is 0 V so all the ions reach the collector, this is the ion density based on that measurement

PT1S

cm^-3

1.0e6>m^-3

0.0

1.0e+08

-999999.0

ion density IDM

Time series defined by using: Epoch

dmdens

Ni from the IDM

the ion density based on the collector current in the IDM, because some or all of the light ions are excluded this density should always be equal to or less than the other ion densities

PT1S

cm^-3

1.0e6>m^-3

0.0

1.0e+08

-999999.0

frac H+ ions in plasma

Time series defined by using: Epoch

frach

Fractional amount of H+ ions in plasma

fractional amount of the plasma that is H+ based on the fitting of the RPA curve, because of uncertainties the value can exceed 1.0; disregard > 1.05 and negative

PT1S

-0.1

1.05

-999999.0

frac H+ quality flag

Time series defined by using: Epoch

frachqual

"Quality flag for fractional H+:1,6-good;2,7-fair;else warn [READ QUALITY FLAG Document]"

1-good 2-fair 3-caution 4-bad 5-uncertain

PT1S

1

5

frac He+ ions in plasma

Time series defined by using: Epoch

frache

Fractional amount of He+ ions in plasma

fractional amount of the plasma that is He+ based on the fitting of the RPA curve, because of uncertainties the value can exceed 1.0; disregard > 1.05 and negative

PT1S

-0.1

1.05

-999999.0

frac He+ quality flag

Time series defined by using: Epoch

frachequal

"Quality flag for fractional He+:1,6-good;2,7-fair;else warn [READ QUALITY FLAG Document]"

1-good 2-fair 3-caution 4-bad 5-uncertain

PT1S

1

5

frac O+ ions in plasma

Time series defined by using: Epoch

fraco

Fractional amount of O+ ions in plasma

fractional amount of the plasma that is O+ based on the fitting of the RPA curve, because of uncertainties the value can exceed 1.0; disregard > 1.05 and negative

PT1S

-0.1

1.05

-999999.0

frac O+ quality flag

Time series defined by using: Epoch

fracoqual

"Quality flag for fractional O+:1,6-good;2,7-fair;else warn [READ QUALITY FLAG Document]"

1-good 2-fair 3-caution 4-bad 5-uncertain

PT1S

1

5

high energy particles

Time series defined by using: Epoch

ebm

Electron background monitor - high energy particle currents detected by the RPA

once every 2 s the RPA repeller voltage is set so high that only high energy electrons or ions reach the collector. A large current indicates high-energy particles or photo-electron production (a sun-glint).

PT1S

A

-2.0e+09

2.0e+09

-999999.0

quality flag for RPA data

Time series defined by using: Epoch

corrpaqual

"Overall quality flag for RPA data:1,6-good;2,7-fair;else warn [READ QUALITY FLAG Document]"

1-good 2-fair 3-caution 4-bad 5-uncertain

PT1S

1

5

quality flag for RPA data

Time series defined by using: Epoch

rpainfo

"Flag for RPA sweep direction:retarding potential: 1-increasing,2-decreasing [READ QUALITY FLAG Document]"

1-retarding potential increasing 2-retarding potential decreasing

PT1S

1

2

geographic latitude

Time series defined by using: Epoch

glat

Geographical latitude

geographic latitude of s/c

PT1S

°

-90.0

90.0

geographic longitude

Time series defined by using: Epoch

glon

Geographic east longitude

geographic east longitude of s/c

PT1S

°

0.0

359.99

magnetic latitude

Time series defined by using: Epoch

mlat

"Magnetic latitude, mapped to 120 km"

magnetic latitude of field line at s/c mapped to 120 km

PT1S

°

-90.0

90.0

magnetic local time

Time series defined by using: Epoch

mlt

"Magnetic local time, mapped to 120 km"

magnetic local time of field line at s/c mapped to 120 km

PT1S

hr

60>s

0.0

23.99

solar zenith angle

Time series defined by using: Epoch

sza

Solar zenith angle

angle between the sun-earth line and the s/c-center of earth line

PT1S

°

0.0

180.0

altitude

Time series defined by using: Epoch

alt

Altitude

altitude of the s/c above earth’s surface

PT1S

km

1.0e3>m

820.0

870.0

#pts vy-vz

Time series defined by using: Epoch

nmbot

"Number of data points in the Vy - Vz average:1-slow mode,6-normal mode"

the IDM operates in two modes: normal mode takes six horizontal and six vertical samples per second, slow mode is for low density conditions where only one sample is taken each second and alternates between directions

PT1S

1.0

10.0

-999999.0

overall quality flag for the IDM data

Time series defined by using: Epoch

idmqual

"Overall quality flag for the IDM data:1,6-good;2,7-fair;else warn [READ QUALITY FLAG Document]"

1-good 2-fair 3-caution 4-bad 5-uncertain 6-good (F17) 7-fair (F17) 8-caution (F17) 9-caution (sun glint or high-energy particles)

PT1S

1

9

spacecraft velocity

Time series defined by using: Epoch

scvel

Spacecraft velocity

orbital velocity of the spacecraft

PT1S

km/s

1.0e3>m/s

-7400.0

7500.0

-999999.0

rpaground

Time series defined by using: Epoch

rpaground

Potential difference between SSIES instruments and spacecraft ground

the DMSP spacecraft charges negative relative to the plasma ground so SSIES is electrically insolated and driven positive relative to spacecraft ground to keep the instrument near the plasma ground

PT1S

°K

500.0

10000.0

-999999.0

potential

Time series defined by using: Epoch

pot

Potential of the SSIES instruments relative to the plasma ground

all the SSIES instruments are held near the plasma ground potential, nominally about -1 V relative to the plasma, this value is calculated from the RPA curve fit, shown as \“SC Potential\” on the plots

PT1S

V

-3.0

2.0

-999999.0

bx

Time series defined by using: Epoch

bx

North component of Earths magnetic field (IGRF)

northward component of the Earths magnetic field at the spacecrafts location calculated by the IGRF model

PT1S

nT

1.0e-9>T

-5000.0

5000.0

-999999.0

by

Time series defined by using: Epoch

by

East component of Earths magnetic field (IGRF)

eastward component of the Earths magnetic field at the spacecrafts location calculated by the IGRF model

PT1S

nT

1.0e-9>T

-5000.0

5000.0

-999999.0

bz

Time series defined by using: Epoch

bz

Vertical downward component of Earths magnetic field (IGRF)

vertical downward component of the Earths magnetic field at the spacecrafts location calculated by the IGRF model

PT1S

nT

1.0e-9>T

-5000.0

5000.0

-999999.0

corotation vel ram

Time series defined by using: Epoch

corvelx

Corotation velocity of ionosphere in the ram direction

the ram component (x) of the corotation speed of the ionosphere at the spacecrafts location

PT1S

m/s

-100.0

0.0

-999999.0

corotation vel crosstrack

Time series defined by using: Epoch

corvely

Corotation velocity of ionosphere in the horizontal crosstrack direction

the crosstrack horizontal component (y) of the corotation speed of the ionosphere at the spacecrafts location

PT1S

m/s

-600.0

600.0

-999999.0

corotation vel vertical

Time series defined by using: Epoch

corvelz

Corotation velocity of ionosphere in the vertical direction

the crosstrack vertical component (z) of the corotation speed of the ionosphere at the spacecrafts location, since DMSP is in a circular orbit, this value is zero

PT1S

m/s

0.0

1.0

-999999.0