Mass spectra count rates for survey purposes only from the POLAR TIMAS instrument. The mass spectral data product consists of 64 mass steps covering the full detector range, for each of 6 large solid angles, for 8 selected energy steps. The data product is accumulated for 2, 4, 8, 16, or 32 spin (6 s) periods. Because of telemetry restrictions only selected data products were telemetered to the ground.

The 6 angular bins cover the full instrumental range and nearly 4pi steradians. Two of the look directions are centered on the spacecraft spin axis. For the first part of the mission, the spin axis was orbit normal and the pitch angles sampled in these look directions are near 90 degrees. The other 4 look directions are in the spin plane. Data are de-spun on board based on the spin rate and time of the "sun pulse". The digital data product provides the center pitch angle of each of the 6 look directions and an estimate of the variation of the pitch angle during the accumulation time.

  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.

NSSDC standard reference time value at the center of the accumulation interval.

NSSDC standard-reference time value at the start of the accumulation interval.

NSSDC standard-reference time value at the end of the accumulation interval.

An array of counts per mass step for each data accumulation interval. The array has dimensions for

* 6 angular accumulation bins covering the full angular range of the instrument. The pitch angles sampled in each of these bins is given by the "Pitch_Angles" variable and associated quality parameters described below.
* 8 energy step bins. The measurement energies associated with each energy step are mode dependent. They are given by the "Energy" variable and associated quality parameters described below.
* 64 mass steps. The position of H+, He++, He+, O+, NO+, and other species in mass step space depends on the MS ELUT (Mass Spectra Energy Look Up Table) which is mode dependent. MS ELUT's are specified for each TIMAS mode. The TIMAS mode is identified by the "ICP" data variable described below.

A two digit number identifing the MS ELUT that determines which 8 of the 28 possible TIMAS energy steps are mapped to the 8 energy bins in the "Mass_Spectra" variable. MS ELUT's are specified for each TIMAS mode. The TIMAS mode is given by the "ICP" data variable described below.

Energy ABOVE Space Craft Potential. An array of 8 energies (in eV) giving the center energies of the data in the "Mass_Spectra" variable in each of the 8 energy step bins for each accumulation interval.

A quality parameter:

  * 0: All data from same instrumental energy step.
  * 1: Data have been accumulated from multiple instrumental energy steps.
  * 99 or 255: Invalid energies.

An array of 8 energies (in eV) giving the upper energies of the data in the "Mass_Spectra" variable in each of the 8 energy step bins for each accumulation interval.

An array of 8 energies (in eV) giving the lower energies of the data in the "Mass_Spectra" variable in each of the 8 energy step bins for each accumulation interval.

A quality indicator of the "Pitch_Angles" variables for each accumulation interval.

  * 0: Valid pitch angles.
  * 4: Pitch angle data compromised (smeared) because of no "spin lock."
  * 10: Insufficient data to calculate pitch angle.
  * 99: Invalid pitch angles.
  * 100: No magnetometer data (required to calculate pitch angle).

An array of 6 pitch angles (in degrees) giving the pitch angle at the center of each of the 6 rather large angular accumulation bins in the "Mass_Spectra" variable.

Look directions of the 6 angular sectors In Fixed Payload Coordinates.

      Normal operations have the angular accumulation bins for the "Mass_Spectra" variable fixed in "Fixed Platform" coordinates. The 6 look directions in FP coordinates defined by the MAG team are:
      
      * 1: in the + Z (spin axis) direction,
      * 2: in the +X direction, (in the spin plane, in the direction closest to the sun direction),
      * 3: +Y direction (completing a right hand coordiante system),
      * 4: -X direction,
      * 5: -Y direction, and
      * 6: -Z (spin axis) direction.
      
      For the first part of the mission the spin axis was orbit normal and so the +/- Z axes sampled mostly near 90 degree pitch angles. Later in the mission the spin axis was pointed nearly normal to the ecliptic.

An array of 6 angles (in degrees) giving the change in magnitude of the pitch angle at the center of each angular accumulation bin over each accumulation interval.

Numbers from 0 to 63 giving the mass step number for each of the 64 mass steps in the "Mass_Spectra" variable.

A two digit number indicating the TIMAS operating mode.

A variable indicating which of the three TIMAS energy range modes was active at the time of data acumulation.

  * 0: Data for the full (15eV to 33 keV) energy range was acquired.
  * 1: Data for a reduced (15 eV to 25 keV) energy range was acquired.
  * 2: Data were sampled only for the lowest energies. Data acquired in this mode has not been validated.

Total counts per spin in the fast event counter

Total Background counts per spin

Number of 6 second spin periods in the accumulation interval for the "Mass_Spectra" variable.

A 2-digit quality number for the "Mass_Spectra" variable.

  * 0: OK;
  * 1: Some data missing;
  * 5: Some warning flags were set;
  * 99: No valid data.
  
  0 and 1 indicated high quality data.

A quality number for the orbital data.

  * 0: OK,
  * 99: Orbit data not available.

The MacIlwain L parameter associated with the "Center_Epoch" of the data accumulation interval.

The magnetic local time associated with the "Center_Epoch" of the data accumulation interval.

The local time associated with the "Center_Epoch" of the data accumulation interval.

The geocentric distance (in units of Earth radii) of the Polar satellite associated with the "Center_Epoch" of the data accumulation interval.

The magnetic latitude (in degrees) associated with the "Center_Epoch" of the data accumulation interval.

The invariant latitude (in degrees) associated with the "Center_Epoch" of the data accumulation interval.