Data Description

This page summarizes information about the selected resource and its origin based on SPASE metadata.

Table of Contents

  1. Product
  2. Repository
  3. Instrument
  4. Observatory
  5. Persons

SPASE version 2.0.0

Numerical Data Product: Polar TIMAS H0 High-resolution Level 1 Data

Resource ID
spase://VMO/NumericalData/POLAR/TIMAS/H0_PT12S Get XML
Name
Polar TIMAS H0 High-resolution Level 1 Data
Description

Mass resolved ion energy angle spectra covering nearly the full 4pi solid angle and the energy range 15 eV/q to 33 eV/q.

H+, O+, He+ and He++ number fluxes and statistical uncertainties processed by the TIMAS science team. Data acquired with various angular and energy resolutions are combined here. Data Quality and other indicators are provided to allow selection of high resolution data (PA_status(ion)=0 and Energy_status(ion)=0 ) and High Quality data (Quality=0). See caveats for the following variables for more detailed information: Quality, PA_status, Energy_status Bcr, Fec, Even_odd, Energy_Range_ID and Spins.

Reference:E.G. Shelley et al., The Toroidal Imaging Mass-Angle Spectrograph (TIMAS) for the Polar Mission, Sp. Sci. Rev, Vol 71, pp 497-530, 1995.

Version 0: December, 1997

Version 1: July, 1998

Version 2: December, 2000 Algorithm improved to more accurately subtract backgrounds arising from spill over from H+ into He++ channel and other sources. Fill data are now inserted for limited energy and pitch angle ranges for Flux_H Flux_O Flux_He_1 and Flux_He_2 variables. The meanging of values of the of Quality variable was slightly modified.

Version 3: June, 2002 Algorithm for V_02 had an error that resulted in under estimation of fluxes in high count regions, i.e. the cusp/cleft and radiation belts. V_03 corrects this error and has been expanded to include calculation of fluxes obtained after December 8, 1998, when TIMAS had a damaging high voltage breakdown that resulted in reduced sensitivity.

Additional information
TIMAS Home Page
Description of data processing and usage
How the the "spill over" and other corrections were made

Details on the "spill over" correction used in data processing

TIMAS PAPCO Module

A PAPCO module for reading and displaying TIMAS (and other POLAR) data.

PAPCO Software

PaPCo is IDL software for data visualization and analysis. It is modular, PaPCo modules built by various institutions and individuals plug into PaPCo core to provide data products. These modules provide graphic panels that are stacked on a time axis. About 60 modules exist, and 30 are supported as core modules that come with PaPCo. There are modules from 15+ spacecraft, including CRRES, Polar, Cassini and Cluster. Data from CDAWeb is plottable as well. The software is open-source, making it very flexible and well-suited for science use.

Contact
Role Person
1. Principal investigator Dr. W. K. Peterson Get XML
Release date
2009-05-20 23:06:12
Repository
Name
CDAWeb Data Repository FTP Interface Get XML
Availability
Online
Access rights
Open
URL
ftp://cdaweb.gsfc.nasa.gov/pub/istp/polar/timas_h0

FTP repository of high-resolution Polar TIMAS data in CDF format at CDAWeb

Format
CDF
Processing level
Calibrated
Provider processing level
Level 1
Provider version
v_03
Instrument
Toroidal Imaging Mass-Angle Spectrograph (TIMAS) Get XML
Measurement type
Energetic particles
Ion composition
Spectrum
Thermal plasma
Temporal description
Start date
1996-03-17 00:03:13
Stop date
1998-12-09 00:00:00
Cadence
12 seconds
Observed regions
Earth.Magnetosphere
Earth.Magnetosphere.Polar
Earth.Magnetosphere.RadiationBelt
Caveats

The Epoch_xx times are the center times of the accumulation interval over which the data were acquired. Depending on instrument mode, fluxes for each major species are accumulated for 2, 4, 8, 16, or 32 spins on-board. This corresponds to 12, 24, 48, 96, or 192 second resolution. The spin accumulation indicator shows the number of spins accumulated for each major ion species for each data record.

Note that data with both high and medium resolution are combined in these files. This means that the energy, angle, and time resolution of some data are less than the resolution provided in the data file.

Early in the mission, The TIMAS high energy limit was 22 keV/e. It was changed to 33 keV/e on June 26, 1996. The Energy_Range_ID flag indicates which energy range the TIMAS instrument was in at the time of data acquisition. Even energy steps (0, 2, ...) are acquired on even spin numbers and odd energy steps (1,3, ...) are acquired on odd spin numbers. High resolution data are included from two spins. To resolve timing uncertainties the Even/Odd indicator is set to indicate which set of energy steps were acquired in the first 6 seconds of the two spin accumulation interval.

The quality of TIMAS data depends on the total number of counts processed by the detector. Some summary quality information is provided in the Quality Flags. The Quality Flags are derived from the fast event counter and other data sources. The TIMAS sensor responds to penetrating radiation that is particularly intense in the radiation belt part of each orbit. The Fluxes returned have been corrected for the background counting rate. Correction of TIMAS fluxes for high count rates increases the uncertainty in the flux values reported. The quality flag is provided as a convenient flag to use to select data that has been acquired in the linear response range of the instrument.

Depending on instrument mode, fluxes for each major species are averaged or not averaged over energy ranges on-board. The energy resolution indicator provides a summary of the energy resolution of the data in each record for each ion species.

Depending on instrument mode, fluxes for each major species are averaged with one of three angular resolutions on-board. The pitch angle resolution indicator provides a summary of the angular resolution of the data in each record for each ion species.

On December 8, 1998 the TIMAS instrument had a high voltage breakdown that resulted in a loss of sensitivity at energies above 700 eV/q and non linear response to ion fluxes at energies below 700 eV/q. After this date the TIMAS K1 data product should be used instead.

Keywords
Energetic Ion Mass-Energy Spectra
Three dimensional Angular Response
↑

Parameters

Parameter #1

Name
Center Epoch for Flux_H
Parameter key
Epoch_H
Description

NSSDC standard-reference time value at the center of the accumulation interval for proton flux.

Caveats

Center epoch in milliseconds since 0 AD of VARIABLE accumulation intervals for H+. See also variables Epoch_start, Epoch_stop, and Spins

Units
ms
Conversion to SI units
1e-3>s
Valid minimum
17-Mar-1996 00:03:13
Valid maximum
04-Apr-2004 00:00:00
Fill value
-1.0E31
Parameter type
Temporal

Parameter #2

Name
Center Epoch for Flux_O
Parameter key
Epoch_O
Description

NSSDC standard-reference time value at the center of the accumulation interval for O+ flux.

Caveats

Center epoch in milliseconds since 0 AD of VARIABLE accumulation intervals for O+. See also variables Epoch_start, Epoch_stop, and Spins

Units
ms
Conversion to SI units
1e-3>s
Valid minimum
17-Mar-1996 00:03:13
Valid maximum
04-Apr-2004 00:00:00
Fill value
-1.0E31
Parameter type
Temporal

Parameter #3

Name
Center Epoch for Flux_He_1
Parameter key
Epoch_He_1
Description

NSSDC standard-reference time value at the center of the accumulation interval for He+ flux.

Caveats

Center epoch in milliseconds since 0 ADof VARIABLE accumulation intervals for He+. See also variables Epoch_start, Epoch_stop, and Spins

Units
ms
Conversion to SI units
1e-3>s
Valid minimum
17-Mar-1996 00:03:13
Valid maximum
04-Apr-2004 00:00:00
Fill value
-1.0E31
Parameter type
Temporal

Parameter #4

Name
Center Epoch for Flux_He_2
Parameter key
Epoch_He_2
Description

NSSDC standard-reference time value at the center of the accumulation interval for He++ flux.

Caveats

Center epoch in milliseconds since 0 ADof VARIABLE accumulation intervals for He++. See also variables Epoch_start, Epoch_stop, and Spins

Units
ms
Conversion to SI units
1e-3>s
Valid minimum
17-Mar-1996 00:03:13
Valid maximum
04-Apr-2004 00:00:00
Fill value
-1.0E31
Parameter type
Temporal

Parameter #5

Name
Start Epoch
Parameter key
Epoch_start
Description

NSSDC standard-reference time value. Start epoch of VARIABLE accumulation intervals for H+, O+, He+ and He++ ions. This variable is used to pass interval times to the TIMAS PAPCO module.

Units
ms
Conversion to SI units
1e-3>s
Structure
Size
4
Elements
Index Name
1 Start Epoch H+
2 Start Epoch O+
3 Start Epoch He+
4 Start Epoch He++
Valid minimum
17-Mar-1996 00:03:13
Valid maximum
04-Apr-2004 00:00:00
Fill value
-1.0E31
Parameter type
Temporal

Parameter #6

Name
Stop Epoch
Parameter key
Epoch_stop
Description

NSSDC standard-reference time value. Stop epoch of VARIABLE accumulation intervals for H+, O+, He+ and He++ ions. This variable is used to pass interval times to the TIMAS PAPCO module.

Units
ms
Conversion to SI units
1e-3>s
Structure
Size
4
Elements
Index Name
1 Stop Epoch H+
2 Stop Epoch O+
3 Stop Epoch He+
4 Stop Epoch He++
Valid minimum
17-Mar-1996 00:03:13
Valid maximum
04-Apr-2004 00:00:00
Fill value
-1.0E31
Parameter type
Temporal

Parameter #7

Name
H+ number flux
Parameter key
Flux_H
Description

H+ number flux for for 28 energy and 12 pitch angle bins. Depends on parameters Epoch_H, energy (lower_energy, upper_energy) and angle (delta_angle).

Caveats

Value set to fill if the Fec is > 400 OR the Bcr is > the Fec OR the data value is > Sigma_H. Negative values reflect low counting rates and background subtraction.

Units
#/(cm^2-s-keV/e-sr)
Structure
Size
28 12
Description

28 energy bins (described by the Energy Range SPASE element) and 12 pitch angle bins. Center of pitch angle bins in degrees (delta = +/- 7.5 deg): 7.5, 22.5, 37.5, 52.5, 67.5, 82.5, 97.5, 112.5, 127.5, 142.5, 157.5, 172.5.

Valid minimum
-0.01
Valid maximum
1.0E8
Fill value
-1.0E31
Particle type
Proton
Quantity
Number flux
Qualifier
Differential
AtomicNumber
1
Energy range
Low energy
16.0
High energy
33298.0
Units
eV/e
Bins
Bin Band name Low energy High energy
1 Flux 25 eV/e 16.0 34.0
2 Flux 45 eV/e 35.2 54.8
3 Flux 68 eV/e 54.1 81.9
4 Flux 93 eV/e 74.6 110.4
5 Flux 126 eV/e 102.8 148.8
6 Flux 171 eV/e 141.5 200.5
7 Flux 233 eV/e 194.8 270.4
8 Flux 316 eV/e 268.1 364.3
9 Flux 430 eV/e 369.2 491.0
10 Flux 585 eV/e 508.1 661.5
11 Flux 795 eV/e 699.2 891.4
12 Flux 1.1 keV/e 962.1 1200.9
13 Flux 1.5 keV/e 1323.6 1617.8
14 Flux 2.0 keV/e 1820.8 2179.2
15 Flux 2.4 keV/e 2228.5 2647.5
16 Flux 3.0 keV/e 2733.1 3210.9
17 Flux 3.6 keV/e 3358.0 3887.8
18 Flux 4.4 keV/e 4119.7 4713.1
19 Flux 5.4 keV/e 5048.3 5718.9
20 Flux 6.6 keV/e 6180.2 6945.2
21 Flux 8.0 keV/e 7560.0 8440.0
22 Flux 9.8 keV/e 9242.0 10262.2
23 Flux 12 keV/e 11313.3 12462.7
24 Flux 15 keV/e 13823.7 15159.5
25 Flux 18 keV/e 16894.5 18436.3
26 Flux 21.5 keV/e 20619.7 22449.1
27 Flux 26 keV/e 25165.3 27336.1
28 Flux 32 keV/e 30702.0 33298.0

Parameter #8

Name
Sigma for H+ number flux
Parameter key
Sigma_H
Description

One standard deviation (sigma) of the H+ number flux based on the observed counts for 28 energy and 12 pitch angle bins. Depends on parameters Epoch_H, energy (lower_energy, upper_energy) and angle (delta_angle).

Caveats

Value clipped at 255% of flux.

Units
% of Flux
Structure
Size
28 12
Description

28 energy bins (described by the Energy Range SPASE element) and 12 pitch angle bins. Center of pitch angle bins in degrees (delta = +/- 7.5 deg): 7.5, 22.5, 37.5, 52.5, 67.5, 82.5, 97.5, 112.5, 127.5, 142.5, 157.5, 172.5.

Valid minimum
0
Valid maximum
255
Fill value
255
Particle type
Proton
Quantity
Number flux
Qualifier
Standard deviation
Differential
AtomicNumber
1
Energy range
Low energy
16.0
High energy
33298.0
Units
eV/e
Bins
Bin Band name Low energy High energy
1 Flux 25 eV/e 16.0 34.0
2 Flux 45 eV/e 35.2 54.8
3 Flux 68 eV/e 54.1 81.9
4 Flux 93 eV/e 74.6 110.4
5 Flux 126 eV/e 102.8 148.8
6 Flux 171 eV/e 141.5 200.5
7 Flux 233 eV/e 194.8 270.4
8 Flux 316 eV/e 268.1 364.3
9 Flux 430 eV/e 369.2 491.0
10 Flux 585 eV/e 508.1 661.5
11 Flux 795 eV/e 699.2 891.4
12 Flux 1.1 keV/e 962.1 1200.9
13 Flux 1.5 keV/e 1323.6 1617.8
14 Flux 2.0 keV/e 1820.8 2179.2
15 Flux 2.4 keV/e 2228.5 2647.5
16 Flux 3.0 keV/e 2733.1 3210.9
17 Flux 3.6 keV/e 3358.0 3887.8
18 Flux 4.4 keV/e 4119.7 4713.1
19 Flux 5.4 keV/e 5048.3 5718.9
20 Flux 6.6 keV/e 6180.2 6945.2
21 Flux 8.0 keV/e 7560.0 8440.0
22 Flux 9.8 keV/e 9242.0 10262.2
23 Flux 12 keV/e 11313.3 12462.7
24 Flux 15 keV/e 13823.7 15159.5
25 Flux 18 keV/e 16894.5 18436.3
26 Flux 21.5 keV/e 20619.7 22449.1
27 Flux 26 keV/e 25165.3 27336.1
28 Flux 32 keV/e 30702.0 33298.0

Parameter #9

Name
O+ number flux
Parameter key
Flux_O
Description

O+ number flux for for 28 energy and 12 pitch angle bins. Depends on parameters Epoch_O, energy (lower_energy, upper_energy) and angle (delta_angle).

Caveats

Value set to fill if the Fec is > 400 OR the Bcr is > the Fec OR the data value is > Sigma_O. Negative values reflect low counting rates and background subtraction.

Units
#/(cm^2-s-keV/e-sr)
Structure
Size
28 12
Description

28 energy bins (described by the Energy Range SPASE element) and 12 pitch angle bins. Center of pitch angle bins in degrees (delta = +/- 7.5 deg): 7.5, 22.5, 37.5, 52.5, 67.5, 82.5, 97.5, 112.5, 127.5, 142.5, 157.5, 172.5.

Valid minimum
-0.01
Valid maximum
1.0E8
Fill value
-1.0E31
Particle type
Ion
Quantity
Number flux
Qualifier
Differential
AtomicNumber
8
Energy range
Low energy
16.0
High energy
33298.0
Units
eV/e
Bins
Bin Band name Low energy High energy
1 Flux 25 eV/e 16.0 34.0
2 Flux 45 eV/e 35.2 54.8
3 Flux 68 eV/e 54.1 81.9
4 Flux 93 eV/e 74.6 110.4
5 Flux 126 eV/e 102.8 148.8
6 Flux 171 eV/e 141.5 200.5
7 Flux 233 eV/e 194.8 270.4
8 Flux 316 eV/e 268.1 364.3
9 Flux 430 eV/e 369.2 491.0
10 Flux 585 eV/e 508.1 661.5
11 Flux 795 eV/e 699.2 891.4
12 Flux 1.1 keV/e 962.1 1200.9
13 Flux 1.5 keV/e 1323.6 1617.8
14 Flux 2.0 keV/e 1820.8 2179.2
15 Flux 2.4 keV/e 2228.5 2647.5
16 Flux 3.0 keV/e 2733.1 3210.9
17 Flux 3.6 keV/e 3358.0 3887.8
18 Flux 4.4 keV/e 4119.7 4713.1
19 Flux 5.4 keV/e 5048.3 5718.9
20 Flux 6.6 keV/e 6180.2 6945.2
21 Flux 8.0 keV/e 7560.0 8440.0
22 Flux 9.8 keV/e 9242.0 10262.2
23 Flux 12 keV/e 11313.3 12462.7
24 Flux 15 keV/e 13823.7 15159.5
25 Flux 18 keV/e 16894.5 18436.3
26 Flux 21.5 keV/e 20619.7 22449.1
27 Flux 26 keV/e 25165.3 27336.1
28 Flux 32 keV/e 30702.0 33298.0

Parameter #10

Name
Sigma for O+ number flux
Parameter key
Sigma_O
Description

One standard deviation (sigma) of the O+ number flux based on the observed counts for 28 energy and 12 pitch angle bins. Depends on parameters Epoch_O, energy (lower_energy, upper_energy) and angle (delta_angle).

Caveats

Value clipped at 255% of flux.

Units
% of Flux
Structure
Size
28 12
Description

28 energy bins (described by the Energy Range SPASE element) and 12 pitch angle bins. Center of pitch angle bins in degrees (delta = +/- 7.5 deg): 7.5, 22.5, 37.5, 52.5, 67.5, 82.5, 97.5, 112.5, 127.5, 142.5, 157.5, 172.5.

Valid minimum
0
Valid maximum
255
Fill value
255
Particle type
Ion
Quantity
Number flux
Qualifier
Standard deviation
Differential
AtomicNumber
8
Energy range
Low energy
16.0
High energy
33298.0
Units
eV/e
Bins
Bin Band name Low energy High energy
1 Flux 25 eV/e 16.0 34.0
2 Flux 45 eV/e 35.2 54.8
3 Flux 68 eV/e 54.1 81.9
4 Flux 93 eV/e 74.6 110.4
5 Flux 126 eV/e 102.8 148.8
6 Flux 171 eV/e 141.5 200.5
7 Flux 233 eV/e 194.8 270.4
8 Flux 316 eV/e 268.1 364.3
9 Flux 430 eV/e 369.2 491.0
10 Flux 585 eV/e 508.1 661.5
11 Flux 795 eV/e 699.2 891.4
12 Flux 1.1 keV/e 962.1 1200.9
13 Flux 1.5 keV/e 1323.6 1617.8
14 Flux 2.0 keV/e 1820.8 2179.2
15 Flux 2.4 keV/e 2228.5 2647.5
16 Flux 3.0 keV/e 2733.1 3210.9
17 Flux 3.6 keV/e 3358.0 3887.8
18 Flux 4.4 keV/e 4119.7 4713.1
19 Flux 5.4 keV/e 5048.3 5718.9
20 Flux 6.6 keV/e 6180.2 6945.2
21 Flux 8.0 keV/e 7560.0 8440.0
22 Flux 9.8 keV/e 9242.0 10262.2
23 Flux 12 keV/e 11313.3 12462.7
24 Flux 15 keV/e 13823.7 15159.5
25 Flux 18 keV/e 16894.5 18436.3
26 Flux 21.5 keV/e 20619.7 22449.1
27 Flux 26 keV/e 25165.3 27336.1
28 Flux 32 keV/e 30702.0 33298.0

Parameter #11

Name
He+ number flux
Parameter key
Flux_He_1
Description

He+ number flux for for 28 energy and 12 pitch angle bins. Depends on parameters Epoch_He_1, energy (lower_energy, upper_energy) and angle (delta_angle).

Caveats

Value set to fill if the Fec is > 400 OR the Bcr is > the Fec OR the data value is > Sigma_He_1. Negative values reflect low counting rates and background subtraction.

Units
#/(cm^2-s-keV/e-sr)
Structure
Size
28 12
Description

28 energy bins (described by the Energy Range SPASE element) and 12 pitch angle bins. Center of pitch angle bins in degrees (delta = +/- 7.5 deg): 7.5, 22.5, 37.5, 52.5, 67.5, 82.5, 97.5, 112.5, 127.5, 142.5, 157.5, 172.5.

Valid minimum
-0.01
Valid maximum
1.0E8
Fill value
-1.0E31
Particle type
Ion
Quantity
Number flux
Qualifier
Differential
AtomicNumber
2
Energy range
Low energy
16.0
High energy
33298.0
Units
eV/e
Bins
Bin Band name Low energy High energy
1 Flux 25 eV/e 16.0 34.0
2 Flux 45 eV/e 35.2 54.8
3 Flux 68 eV/e 54.1 81.9
4 Flux 93 eV/e 74.6 110.4
5 Flux 126 eV/e 102.8 148.8
6 Flux 171 eV/e 141.5 200.5
7 Flux 233 eV/e 194.8 270.4
8 Flux 316 eV/e 268.1 364.3
9 Flux 430 eV/e 369.2 491.0
10 Flux 585 eV/e 508.1 661.5
11 Flux 795 eV/e 699.2 891.4
12 Flux 1.1 keV/e 962.1 1200.9
13 Flux 1.5 keV/e 1323.6 1617.8
14 Flux 2.0 keV/e 1820.8 2179.2
15 Flux 2.4 keV/e 2228.5 2647.5
16 Flux 3.0 keV/e 2733.1 3210.9
17 Flux 3.6 keV/e 3358.0 3887.8
18 Flux 4.4 keV/e 4119.7 4713.1
19 Flux 5.4 keV/e 5048.3 5718.9
20 Flux 6.6 keV/e 6180.2 6945.2
21 Flux 8.0 keV/e 7560.0 8440.0
22 Flux 9.8 keV/e 9242.0 10262.2
23 Flux 12 keV/e 11313.3 12462.7
24 Flux 15 keV/e 13823.7 15159.5
25 Flux 18 keV/e 16894.5 18436.3
26 Flux 21.5 keV/e 20619.7 22449.1
27 Flux 26 keV/e 25165.3 27336.1
28 Flux 32 keV/e 30702.0 33298.0

Parameter #12

Name
Sigma for He+ number flux
Parameter key
Sigma_He_1
Description

One standard deviation (sigma) of the He+ number flux based on the observed counts for 28 energy and 12 pitch angle bins. Depends on parameters Epoch_He_1, energy (lower_energy, upper_energy) and angle (delta_angle).

Caveats

Value clipped at 255% of flux.

Units
% of Flux
Structure
Size
28 12
Description

28 energy bins (described by the Energy Range SPASE element) and 12 pitch angle bins. Center of pitch angle bins in degrees (delta = +/- 7.5 deg): 7.5, 22.5, 37.5, 52.5, 67.5, 82.5, 97.5, 112.5, 127.5, 142.5, 157.5, 172.5.

Valid minimum
0
Valid maximum
255
Fill value
255
Particle type
Ion
Quantity
Number flux
Qualifier
Standard deviation
Differential
AtomicNumber
2
Energy range
Low energy
16.0
High energy
33298.0
Units
eV/e
Bins
Bin Band name Low energy High energy
1 Flux 25 eV/e 16.0 34.0
2 Flux 45 eV/e 35.2 54.8
3 Flux 68 eV/e 54.1 81.9
4 Flux 93 eV/e 74.6 110.4
5 Flux 126 eV/e 102.8 148.8
6 Flux 171 eV/e 141.5 200.5
7 Flux 233 eV/e 194.8 270.4
8 Flux 316 eV/e 268.1 364.3
9 Flux 430 eV/e 369.2 491.0
10 Flux 585 eV/e 508.1 661.5
11 Flux 795 eV/e 699.2 891.4
12 Flux 1.1 keV/e 962.1 1200.9
13 Flux 1.5 keV/e 1323.6 1617.8
14 Flux 2.0 keV/e 1820.8 2179.2
15 Flux 2.4 keV/e 2228.5 2647.5
16 Flux 3.0 keV/e 2733.1 3210.9
17 Flux 3.6 keV/e 3358.0 3887.8
18 Flux 4.4 keV/e 4119.7 4713.1
19 Flux 5.4 keV/e 5048.3 5718.9
20 Flux 6.6 keV/e 6180.2 6945.2
21 Flux 8.0 keV/e 7560.0 8440.0
22 Flux 9.8 keV/e 9242.0 10262.2
23 Flux 12 keV/e 11313.3 12462.7
24 Flux 15 keV/e 13823.7 15159.5
25 Flux 18 keV/e 16894.5 18436.3
26 Flux 21.5 keV/e 20619.7 22449.1
27 Flux 26 keV/e 25165.3 27336.1
28 Flux 32 keV/e 30702.0 33298.0

Parameter #13

Name
He++ number flux
Parameter key
Flux_He_2
Description

He++ number flux for for 28 energy and 12 pitch angle bins. Depends on parameters Epoch_He_2, energy (lower_energy, upper_energy) and angle (delta_angle).

Caveats

Value set to fill if the Fec is > 400 OR the Bcr is > the Fec OR the data value is > Sigma_He_2. Negative values reflect low counting rates and background subtraction.

Units
#/(cm^2-s-keV/e-sr)
Structure
Size
28 12
Description

28 energy bins (described by the Energy Range SPASE element) and 12 pitch angle bins. Center of pitch angle bins in degrees (delta = +/- 7.5 deg): 7.5, 22.5, 37.5, 52.5, 67.5, 82.5, 97.5, 112.5, 127.5, 142.5, 157.5, 172.5.

Valid minimum
-0.01
Valid maximum
1.0E8
Fill value
-1.0E31
Particle type
AlphaParticle
Quantity
Number flux
Qualifier
Differential
AtomicNumber
2
Energy range
Low energy
16.0
High energy
33298.0
Units
eV/e
Bins
Bin Band name Low energy High energy
1 Flux 25 eV/e 16.0 34.0
2 Flux 45 eV/e 35.2 54.8
3 Flux 68 eV/e 54.1 81.9
4 Flux 93 eV/e 74.6 110.4
5 Flux 126 eV/e 102.8 148.8
6 Flux 171 eV/e 141.5 200.5
7 Flux 233 eV/e 194.8 270.4
8 Flux 316 eV/e 268.1 364.3
9 Flux 430 eV/e 369.2 491.0
10 Flux 585 eV/e 508.1 661.5
11 Flux 795 eV/e 699.2 891.4
12 Flux 1.1 keV/e 962.1 1200.9
13 Flux 1.5 keV/e 1323.6 1617.8
14 Flux 2.0 keV/e 1820.8 2179.2
15 Flux 2.4 keV/e 2228.5 2647.5
16 Flux 3.0 keV/e 2733.1 3210.9
17 Flux 3.6 keV/e 3358.0 3887.8
18 Flux 4.4 keV/e 4119.7 4713.1
19 Flux 5.4 keV/e 5048.3 5718.9
20 Flux 6.6 keV/e 6180.2 6945.2
21 Flux 8.0 keV/e 7560.0 8440.0
22 Flux 9.8 keV/e 9242.0 10262.2
23 Flux 12 keV/e 11313.3 12462.7
24 Flux 15 keV/e 13823.7 15159.5
25 Flux 18 keV/e 16894.5 18436.3
26 Flux 21.5 keV/e 20619.7 22449.1
27 Flux 26 keV/e 25165.3 27336.1
28 Flux 32 keV/e 30702.0 33298.0

Parameter #14

Name
Sigma for He++ number flux
Parameter key
Sigma_He_2
Description

One standard deviation (sigma) of the He+ number flux based on the observed counts for 28 energy and 12 pitch angle bins. Depends on parameters Epoch_He_2, energy (lower_energy, upper_energy) and angle (delta_angle).

Caveats

Value clipped at 255% of flux.

Units
% of Flux
Structure
Size
28 12
Description

28 energy bins (described by the Energy Range SPASE element) and 12 pitch angle bins. Center of pitch angle bins in degrees (delta = +/- 7.5 deg): 7.5, 22.5, 37.5, 52.5, 67.5, 82.5, 97.5, 112.5, 127.5, 142.5, 157.5, 172.5.

Valid minimum
0
Valid maximum
255
Fill value
255
Particle type
AlphaParticle
Quantity
Number flux
Qualifier
Standard deviation
Differential
AtomicNumber
2
Energy range
Low energy
16.0
High energy
33298.0
Units
eV/e
Bins
Bin Band name Low energy High energy
1 Flux 25 eV/e 16.0 34.0
2 Flux 45 eV/e 35.2 54.8
3 Flux 68 eV/e 54.1 81.9
4 Flux 93 eV/e 74.6 110.4
5 Flux 126 eV/e 102.8 148.8
6 Flux 171 eV/e 141.5 200.5
7 Flux 233 eV/e 194.8 270.4
8 Flux 316 eV/e 268.1 364.3
9 Flux 430 eV/e 369.2 491.0
10 Flux 585 eV/e 508.1 661.5
11 Flux 795 eV/e 699.2 891.4
12 Flux 1.1 keV/e 962.1 1200.9
13 Flux 1.5 keV/e 1323.6 1617.8
14 Flux 2.0 keV/e 1820.8 2179.2
15 Flux 2.4 keV/e 2228.5 2647.5
16 Flux 3.0 keV/e 2733.1 3210.9
17 Flux 3.6 keV/e 3358.0 3887.8
18 Flux 4.4 keV/e 4119.7 4713.1
19 Flux 5.4 keV/e 5048.3 5718.9
20 Flux 6.6 keV/e 6180.2 6945.2
21 Flux 8.0 keV/e 7560.0 8440.0
22 Flux 9.8 keV/e 9242.0 10262.2
23 Flux 12 keV/e 11313.3 12462.7
24 Flux 15 keV/e 13823.7 15159.5
25 Flux 18 keV/e 16894.5 18436.3
26 Flux 21.5 keV/e 20619.7 22449.1
27 Flux 26 keV/e 25165.3 27336.1
28 Flux 32 keV/e 30702.0 33298.0

Parameter #15

Name
Energy Range
Parameter key
Energy_Range_ID
Description

Energy Range Identification: 0: Full energy range; 1: Reduced energy range; 2: Low energy range.

TIMAS is operated in one of 3 energy ranges. Energy_Range_ID indicates which of the 3 instrumental energy ranges is currently active:

Energy_Range_ID=0: Full instrumental energy range, valid data are in energy steps 1 through 28) Energy_Range_ID=1: Reduced instrumental energy range, valid data are in energy steps 1 through 26 Energy_Range_ID=2: Low instrumental energy range, no valid data were acquired in this mode.

In the table below the lower, center, and upper energies for each of the 28 fixed energy steps are given. The upper and lower energies bound the full width at half maximum energy response of the detector.

Step E_lower E_center E_upper 1 16.0 25.0 34.0 2 35.2 45.0 54.8 3 54.1 68.0 81.9 4 74.6 92.5 110.4 5 102.8 125.8 148.8 6 141.5 171.0 200.5 7 194.8 232.6 270.4 8 268.1 316.2 364.3 9 369.2 430.1 491.0 10 508.1 584.8 661.5 11 699.2 795.3 891.4 12 962.1 1081.5 1200.9 13 1323.6 1470.7 1617.8 14 1820.8 2000.0 2179.2 15 2228.5 2438.0 2647.5 16 2733.1 2972.0 3210.9 17 3358.0 3622.9 3887.8 18 4119.7 4416.4 4713.1 19 5048.3 5383.6 5718.9 20 6180.2 6562.7 6945.2 21 7560.0 8000.0 8440.0 22 9242.0 9752.1 10262.2 23 11313.3 11888.0 12462.7 24 13823.7 14491.6 15159.5 25 16894.5 17665.4 18436.3 26 20619.7 21534.4 22449.1 27 25165.3 26250.7 27336.1 28 30702.0 32000.0 33298.0

Valid minimum
0
Valid maximum
3
Fill value
255
Parameter type
Other

Parameter #16

Name
even_odd
Parameter key
Even_odd
Description

Even/Odd Spin Identification

0 first (even) spin with even numbered energy steps 1 second (odd) spin with odd numbered energy steps.

Caveats

TIMAS samples 28 energy steps over the full energy range every two spins (12 seconds). On even numbered spins the lowest energy step (centered at 25 eV/e) and alternate energy steps over the full energy range are sampled. On odd spins the second energy step (centered at 45 eV/e) and alternate energy steps to the maximum are sampled.

Valid minimum
0
Valid maximum
1
Fill value
255
Parameter type
Other

Parameter #17

Name
FEC counts
Parameter key
Fec
Description

Total counts per spin in the fast event counter

Caveats

The TIMAS detector has a non linear response at high count rates that is, to some extent corrected for in the software that generated the data here. The correction, however introduces some uncertainty. The FEC count rate is carried as an indication of the corrections applied to the raw data.

Units
Counts per spin
Valid minimum
0.0
Valid maximum
1.0E8
Fill value
-1.0E31
Parameter type
Other

Parameter #18

Name
Background counts
Parameter key
Bcr
Description

Total Background counts per spin

Caveats

Total background counts per spin

Units
Counts per spin
Valid minimum
0.0
Valid maximum
1.0E8
Fill value
-1.0E31
Parameter type
Other

Parameter #19

Name
Spins Accumulated
Parameter key
Spins
Description

Number of spins accumulated for each of the four ion species

Units
# of spins
Structure
Size
4
Elements
Index Name Valid min Valid max Fill value
1 H+ spins 0 32 255
2 O+ spins 0 32 255
3 He+ spins 0 32 255
4 He++ spins 0 32 255
Parameter type
Other

Parameter #20

Name
Energy Resolution Flags
Parameter key
Energy_status
Description

Energy Resolution Indicators

TIMAS data are available from operational modes with full (28 bins) or moderate (7 bins) energy resolution. These data were assembled from various data products with different energy resolution. Data are given with full 28 energy step resolution EVEN IF ONLY 7 energy step resolution data are available. This flag documents the resolution of the data included in the average.

Values are: 0 All single spin 14 energy step data. 1 Mostly 14 energy step data. Some 7 energy step. All one or two spin. 2 Mostly 7 energy step data. Some 14 energy step. All one or two spin. 3 All one or two spin 7 energy step data. 4 Mostly 14 energy step data. Some 7 energy step multispins. 5 Mostly one or two spin 7 energy step data. Some multispins. 6 Mostly multispin 7 energy step data. 7 All multispin 7 energy step data. 99 Invalid energies.

Some of these conditions (1,2,4,5,6) are very rare.

Structure
Size
4
Elements
Index Name
1 H+ E-Res
2 O+ E-Res
3 He+ E-Res
4 He++ E-Res
Valid minimum
0
Valid maximum
99
Fill value
255
Parameter type
Other

Parameter #21

Name
Pitch Angle Resolution
Parameter key
PA_status
Description

Pitch Angle Resolution Flags TIMAS data are available from operational modes with various anglular resolutions. These data were assembled from various data products with different angular resolutions. Data are given in this product with full 12 angular bin resolution EVEN IF 12 angular bin resolution is not available in the input data. This flag documents the resolution of the data included in the average.

Values are: 0 All 22 degree data. 1 Mostly 22 degree data. 2 Mostly 45 degree data. 3 All 45 degree data. 4 Smeared 22 degree data. Not spin locked. 5 Smeared 45 degree data. Not spin locked. 99 Invalid pitch angles.

Caveats

IMPORTANT NOTE: VALID DATA ARE INCLUDED FOR INTERVALS WITH INVALID PITCH ANGLES. When calculating the omnidirectonal flux average for intervals with invalid pitch angles the values of the pitch angles must be ignored.

Structure
Size
4
Elements
Index Name
1 H+ ang res flag
2 O+ ang res flag
3 He+ ang res flag
4 He++ ang res flag
Valid minimum
0
Valid maximum
99
Fill value
255
Parameter type
Other

Parameter #22

Name
Data Quality Flags
Parameter key
Quality
Description

Correction of TIMAS fluxes for high count rates increases the uncertainty in the flux values reported. The quality flag is provided as a convenient flag to use to select data that has been acquired in the linear response range of the instrument. A quality flag is in the range 0-99 with the following values/meanings

0 OK. 1 Some data missing. 2 More than 5% data missing 3 Not used 4 Not used 5 Warning flags set 6 Not used 99 No valid data.

0-1 indicate high quality data while 2 indicates adequate quality data.

Structure
Size
4
Elements
Index Name
1 H+ Qual
2 O+ Qual
3 He+ Qual
4 He++ Qual
Valid minimum
0
Valid maximum
99
Fill value
255
Parameter type
Other

Parameter #23

Name
Ion Energy
Parameter key
energy
Description

Energy bin values ABOVE space craft potential

Units
eV
Structure
Size
28
Valid minimum
15.0
Valid maximum
35000.0
Parameter type
Other

Parameter #24

Name
Upper Energy
Parameter key
upper_energy
Description

Upper limit of FWHM Energy pass band

Units
eV
Structure
Size
28
Valid minimum
15.0
Valid maximum
35000.0
Parameter type
Other

Parameter #25

Name
Lower Energy
Parameter key
lower_energy
Description

Lower limit of FWHM Energy pass band

Units
eV
Structure
Size
28
Valid minimum
15.0
Valid maximum
35000.0
Parameter type
Other

Parameter #26

Name
Pitch Angle
Parameter key
angle
Description

Center of pitch angle bins. Bins are 15 degrees wide (i.e. +/-7.5 degrees from the center).

Units
deg
Structure
Size
12
Valid minimum
0.0
Valid maximum
180.0
Parameter type
Other
↑

SPASE version 2.0.0

Instrument: Toroidal Imaging Mass-Angle Spectrograph (TIMAS)

Instrument ID
spase://SMWG/Instrument/POLAR/TIMAS Get XML
Name
Toroidal Imaging Mass-Angle Spectrograph (TIMAS)
Alternate name
TIMAS
1996-013A-01
Description

This investigation onboard POLAR spacecraft utilizes a toroidal ion mass spectrograph (TIMS) to fulfill its objectives, which are to study (1) the properties, location, and morphology of the principal source region for the entry of solar wind plasma into the magnetosphere, i.e., the polar cusp; (2) the properties, location, and morphology of the principal source region for hot ionospheric plasma in the magnetosphere, i.e., the auroral acceleration region; (3) the details of the processes by which the source plasmas are injected into trapped orbits, with special emphasis on the mass dependence of these processes; (4) details of the processes by which relatively cool source plasmas are energized into hot plasma, with special emphasis on the mass dependence of these processes; and (5) the details of the processes by which the hot magnetospheric plasma are lost, for example through wave-particle scattering and charge exchange, with special emphasis on the mass dependence of these processes.

The Toroidal Imaging Mass-Angle Spectrograph (TIMAS) instrument measures the full three-dimensional velocity distribution functions of all major magnetospheric ion species with one-half spin period time resolution. The TIMAS is a first order double focusing (angle and energy), imaging spectrograph that simultaneously measures all mass per charge components from 1 AMU/e to greater than 32 AMU/e over a nearly 360 degrees by 10 degree instantaneous field-of-view in 20 milliseconds. Mass per charge is dispersed radially on an anular microchannel plate detector and the azimuthal position on the detector is a map of the instantaneous 360 degrees field of view. With the rotation of the spacecraft, the TIMAS sweeps out a 4pi solid angle image in a half spin period. The energy per charge range from 15eV/e to 32 keV/e is covered in 28 non-contiguous steps spaced approximately logarithmically with adjacent steps separated by about 30%. In order to handle the large volume of data within the telemetry limitations the distributions are compressed to varying degrees in angle and energy, log-count compressed and then further compressed by a lossless technique. This data processing task is supported by two SA3300 microprocessors. The voltages (up to + 5 kV) for the tandem toroidal electrostatic analyzers are supplied from common high voltage supplies using optically controlled series-shunt regulators.

Additional information
Full instrument description

Full and detailed descriptions of the TIMAS instrument goals, design and calibration (written in 1996).

NSSDC's Master Catalog

Information about the Toroidal Imaging Mass-Angle Spectrograph (TIMAS) experiment on the POLAR mission.

Contact
Role Person
1. Principal investigator Dr. W. K. Peterson Get XML
Release date
2009-05-20 21:10:13
Instrument type
Energetic Particle Instrument
Mass Spectrometer
Investigation name
Toroidal Imaging Mass-Angle Spectrograph (TIMAS) on Polar
Observatory
POLAR Get XML
↑

SPASE version 2.0.0

Observatory: POLAR

Observatory ID
spase://SMWG/Observatory/POLAR Get XML
Name
POLAR
Alternate name
Polar Plasma Laboratory
GGS/Polar
ISTP/Polar
Description

POLAR is one of four spacecraft in the Global Geospace Science (GGS) program. These are among the six spacecraft in the International Solar Terrestrial Physics (ISTP) program. POLAR provides multi-wavelength imaging of the aurora, measuring plasma entry into the polar magnetosphere and geomagnetic tail, the flow of plasmas to and from the ionosphere, and the deposition of particle energy in the ionosphere and upper atmosphere. POLAR has on-board propulsion systems and a design lifetime of three to five years, with redundant subsystems. POLAR is cylindrical, approximately 2.8 m in diameter by 1.25 m high (plus 1.25 m for its two despun platforms), with body-mounted solar cells, weighs 1250 kg and uses 333 W of power. The spin rate is 10 rpm around an axis approximately normal to the orbital plane. It has long wire spin-plane antennas, inertial booms, and spin-plane appendages to support sensors. POLAR has two despun gimbaled instrument platforms, and booms are deployed along both Z axes. Data are stored using on-board tape recorders and are relayed to the Deep Space Network at 600 kbps maximum (250 kbps nominal) although the average real-time data rate for POLAR is 41.6 kbps. POLAR has a 22.6-h polar orbit (90 deg inclination), with perigee and apogee of 11,500 and 57,000 km. Polar was launched to observe the polar magnetosphere and, as its orbit has precessed with time, has observed the equatorial inner magnetosphere and is now carrying out an extended period of southern hemisphere coverage. Details on the POLAR mission and instrumentation are provided in Space Science Reviews (Vol. 71, Nos. 1-4, 1995) and reprinted in The Global Geospace Mission, edited by C. T. Russell (Kluwer, 1995).

Additional information
NASA Polar Project

Web site of NASA Polar Mission, including overview, data products, FTP to the data, publications, educational outreach, orbits, instrument descriptions, contacts, news archive, and ISTP archive.

NSSDC's Master Catalog

Information about the Polar mission

Contact
Role Person
1. Project scientist Dr. John B. Sigwarth Get XML
Release date
2009-05-20 20:00:12
Prior ID
spase://vspo/observatory/67
Location
Region
Earth.Magnetosphere
Earth.Magnetosphere.Polar
Earth.Magnetosphere.RadiationBelt
↑

SPASE version 2.0.0

Person: Dr. W. K. Peterson

Name
Dr. W. K. Peterson
Organization
Laboratory for Atmospheric and Space Physics LASP, University of Colorado
Email
Bill.Peterson@lasp.colorado.edu
Phone
(303) 492-0686
Person ID
spase://SMWG/Person/W.K.Peterson Get XML
Release date
2008-06-10 16:06:25
↑

SPASE version 2.0.0

Person: Dr. Robert E. McGuire

Name
Dr. Robert E. McGuire
Organization
NASA Goddard Space Flight Center
Address
Code 672, Greenbelt, MD 20771, USA
Email
mcguire@mail630.gsfc.nasa.gov
Phone
1-301-286-7794
Person ID
spase://SMWG/Person/Robert.E.McGuire Get XML
Release date
2007-05-30 15:25:24
↑

SPASE version 2.0.0

Person: Dr. John B. Sigwarth

Name
Dr. John B. Sigwarth
Organization
NASA Goddard Space Flight Center
Address
NASA/GSFC, Code 674, Greenbelt, MD 20771
Email
pwg_project@nssdc.nasa.gov
Person ID
spase://SMWG/Person/John.B.Sigwarth Get XML
Release date
2007-12-04 23:11:21
↑

SPASE version 1.2.0

Repository: CDAWeb Data Repository FTP Interface

Repository ID
spase://SMWG/Repository/NASA/GSFC/SPDF/CDAWeb Get XML
Name
CDAWeb Data Repository FTP Interface
Description

Coordinated Data Analysis Web (CDAWeb) supports not only interactive plotting of variables from multiple instruments on multiple investigations simultaneously on arbitrary, user-defined time-scales. It also supports data retrieval in various formats using its interactive web interface or ftp service.

Additional information
CDAWeb Home Page

Coordinated Data Analysis Web (CDAWeb) home page at Space Physics Data Facility of the NASA Goddard Space Flight Center.

Contact
Role Person
1. Project scientist Dr. Robert E. McGuire Get XML
Release date
2008-08-26 21:14:34
Prior ID
spase://VMO/Repository/CDAWeb
↑