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.
Version:2.2.9
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.
| Role | Person | |
|---|---|---|
| 1. | PrincipalInvestigator | spase://SMWG/Person/W.K.Peterson |
Details on the "spill over" correction used in data processing
A PAPCO module for reading and displaying TIMAS (and other POLAR) data.
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.
FTP repository of high-resolution Polar TIMAS data in CDF format at CDAWeb
In CDF via HTTP from SPDF
NSSDC standard-reference time value at the center of the accumulation interval for proton flux.
NSSDC standard-reference time value at the center of the accumulation interval for O+ flux.
NSSDC standard-reference time value at the center of the accumulation interval for He+ flux.
NSSDC standard-reference time value at the center of the accumulation interval for He++ flux.
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.
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.
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).
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.
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).
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.
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).
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.
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).
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.
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).
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.
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).
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.
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).
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.
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).
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.
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
Even/Odd Spin Identification
0 first (even) spin with even numbered energy steps
1 second (odd) spin with odd numbered energy steps.
Total counts per spin in the fast event counter
Total Background counts per spin
Number of spins accumulated for each of the four ion species
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.
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.
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.
Energy bin values ABOVE space craft potential
Upper limit of FWHM Energy pass band
Lower limit of FWHM Energy pass band
Center of pitch angle bins. Bins are 15 degrees wide (i.e. +/-7.5 degrees from the center).