Full Definitions

Full Definitions of TIMAS Key Parameters

Also see: Brief overview of Key Parameter Types

Parameter Names in Alphabetical Order

A short description and link to the full parameter description in the Common Data Format skeleton table is also provided for record variable parameters.

Densities
one or three mode dependent energy ranges
- Density_H Hydrogen ion partial density for 3 mode dependent energy ranges (low,mid,hi)
- Density_He_1 Singly charged helium ion partial density over the full mode dependent energy range.
- Density_He_2 Doubly charged helium ion partial density over the full mode dependent energy range.
- Density_O Oxygen ion partial density for 3 mode dependent energy ranges (low,mid,hi)
Energy_Range_ID Integer indicating which of three instrumental energy range modes is active for each one minute key parameter averaging interval.
```
	Key:	0=full, 1=reduced, 2=low
		See Tablefor energy range values
```
Epoch The time at the time at the center of the averaging interval encoded into the 8 byte CDF Epoch format.
format_geographic
format_geomagnetic
format_time
Geomagnetic_Position A three element array with Invariant Latitude (degrees) Magnetic Local Time (decimal hours) and Geomagnetic latitude (degrees) from the predicted orbit variables available at the time of generation.
Geographic_Position A htee element array with Latitude (degrees) Longitude (degrees) and Geocentric Distance ( R/Re in Earth radii) from the predicted orbit variables available at the time of generation.
label_Energy_ranges
label_geomagnetic
label_geographic
label_H_density
label_H_Full_Velocity
label_H_Low_Velocity
label_O_density
label_O_Full_Velocity
label_O_Low_Velocity
label_H_Low_Temp
label_H_full_Temp
label_O_Low_Temp
label_O_full_Temp
label_time
Labels_for_TIMAS_B
Labels_for_Quality
Mode_ID The Serial Number (Range: 0-255) of the TIMAS ICP Table in use.
Quality Parameters
- Quality_H Quality indicators for the 3 mode dependent Hydrogen ion energy ranges.
- Quality_He_1 Quality indicator for the mode dependent singly charged helium ion energy range.
- Quality_He_2 Quality indicator for the mode dependent singly charged helium ion energy range.
- Quality_O Quality indicators for the 3 mode dependent Oxygen ion energy ranges.
Temperatures.
perpendicular
parallel
a mode dependent energy rangeThe magnetic field used for the calculation is determined from the measured magnetic field reported every 9.2 seconds by the Magnetometer instrument in the spacecraft housekeeping data. A diagnostic parameter (TIMAS_B) is provided so that the averaged one minute magnetic field used for the key parameter calculation can be compared with fully calibrated magnetometer data available from the Magnetic field Experiment.
- - Temp_H_low H+ temperatures for the low energy range are determined from moments of the average three dimensional distribution function integrated over the mode dependent low KP energy range.
  - Temp_O_low O+ temperatures for the low energy range are determined from moments of the average three dimensional distribution function integrated over the mode dependent low KP energy range.
  - Temperature_H H+ Temperatures are determined from moments of the average three dimensional distribution function integrated over the full instrument energy range. The instrumental energy range is mode dependent.
  - Temperature_O O+ Temperatures are determined from moments of the average three dimensional distribution function integrated over the full instrument energy range. The instrumental energy range is mode dependent.
TIMAS_BUnits nT. The one minute average magnetic field in Fixed Platform (FP) Coordinates. This average is calculated from the 9.2 second magnetic field values available in the spacecraft housekeeping records. These values are used by the TIMAS software to report values of key parameter velocities and temperatures in a magnetic field aligned coordinate system. The FP Z axis is parallel to spin axis, The X axis perpendicular to the Z axis and in the meridian plane containing a radius vector to the Sun. The Y axis completes a right hand system. NOTE: TIMAS_B is a diagnostic parameter. It should NOT be used for analysis.
Time_PB5 A three element array [Year, Day of Year, Milliseconds of Day] giving the time at the center of the the one minute averaging interval.
units_geographic
units_geomagnetic
units_time
VelocitiesVelocities are reported in units of km/s in a field aligned coordinate system. The first (X) component is aligned with the direction of the one minute average magnetic field determined from the measured magnetic field reported every 9.2 seconds by the Magnetometer instrument in the spacecraft housekeeping data. A diagnostic parameter (TIMAS_B) is provided so that the averaged one minute magnetic field used for the key parameter calcualtion can be compared with fully calibrated magnetometer data available from the Magnetic field Experiment.Rotation from Fixed-Payload (FP) coordinated to field aligned coordinates is done by first rotating about the FP Z (spin axis) and then about the intermediate Y axis until the X axis is aligned with the magnetic field direction. A diagnostic parameter (TIMAS_B) is provided so that the averaged one minute magnetic field used for the key parameter calcualtion can be compared with fully calibrated magnetometer data available from the Magnetic field Experiment.
- Vel_H_low Three components (x,y,z) of velocity from the mode dependent low KP energy range.
- Vel_O_low Three components (x,y,z) of velocity from the mode dependent low KP energy range.
- Velocity_H Three components (x,y,z) of velocity from the full mode dependent instrumental energy range.
- Velocity_O Three components (x,y,z) of velocity from the full mode dependent instrumental energy range.

More Information is available

Prepared by Bill Peterson

Updated 08/09/2005 by Daryl Carr