| DATA_SET_DESCRIPTION |
Data Set Overview
=================
The Thermal Evolved Gas Analyzer (TEGA) is designed to analyze
~50 mg of fine grained Martian soil or rock fragments. TEGA
consists of four basic components: a soil delivery system,
an oven/calorimeter thermal analyzer (TA), a gas storage and
handling system, and a mass spectrometer acting as an
evolved-gas analyzer (EGA). A full description of the TEGA
instrument can be found in [BOYNTONETAL2008].
The data set PHX MARS THERMAL EVOLVED GAS ANALYZER 3 RDR
is a time series collection of TA, EGA, engineering, and
commanding measurements from the TEGA aboard the Mars Phoenix
Lander. The RDR data are converted from the EDR raw values to
scientifically useful data including physical units. Data types
included in this data set are engineering data, calorimeter data
from the TA,sweep mode EGA data, and mass hopping mode EGA data.
Data are sorted by time, with each data file containing one
measurement day's worth of data from midnight to midnight UTC.
TEGA is designed to analyze 8 individual Martian regolith
samples, one sample in each of the eight single use ovens.
The EGA portion of the instrument will not only analyze the
gases evolved from the samples heated in the ovens, but will
also analyzed samples of the Martian atmosphere.
TEGA is expected to operate for 45 days. During operations
science, engineering and housekeeping data are downloaded from
the lander by the Jet Propulsion Laboratory (JPL) into the
Telemetry Data System(TDS). The TDS sends data to a process
that translates data packets and
examines instrument health via messages. Data are output to a
spooler that passes them to the University of Arizona (UA)
database ingest process. The ingest process inputs raw data
into the UA database. Data are retrieved from the UA database
to build the TEGA RDR data products.
The TEGA RDR data set is intended to be the first reduced data
product for the TEGA instrument. It should be useful to those
scientists who are experienced in calorimetry and mass
spectrometry.
Parameters
==========
The TEGA RDR data set is composed of four data types. The
objective of compiling the TEGA RDR is to create a record of
of data that has been converted to scientifically useful
physical units and has been combined with useful calibration
information. The following paragraphs discuss the parameters of
interest in each of the data types.
SCRDR
-----
The SC data are time series records taken over the course
of a measurement day. Data files are labeled with the date.
Individual records are a single data collection interval. SC
data are the science data produced by the TA.
EGSRDR
------
The EGA data are time series records taken over the course of
a measurement day. Data files are labeled with the date.
Individual records are a single data collection interval.
EGA data are the science data produced by the EGA mass
spectrometer in sweep mode.
EGHRDR
------
The EGH data are time series records taken over the course of
a measurement day. Data files are labeled with the date.
Individual records are a single data collection interval. EGH
data are the science data produced by the EGA mass
spectrometer in mass hopping mode.
ENGRDR
------
The Engineering data are time series records for each
engineering parameter taken over the course of a measurement
day. Data files are grouped in the ENG folder and are labeled
with the engineering parameter name. Individual records are a
single data collection interval that is variable in duration.
Engineering values are reported by parameter name and include
collection time, and parameter value. In general,
temperatures are reported in Celsius, currents in milliamps,
and potentials in volts. The ENGRDR label file is the
definitive source for the units of measure. Engineering
values are specific monitor values recorded by TEGA.
Processing
==========
TEGA data (both science and engineering) are downloaded from
the Phoenix Mars Lander by JPL into the Telemetry Data System
(TDS). The TDS sends the data to a process called TEGA_tl, that
translates GRS packets from any source to any destination and
examines instrument health via messages. The data are checked
for packet types, header information, messages, or errors.
Data are output to a spooler, which passes data to the UA
database ingestion process. The ingestion process inputs raw
telemetry data into the database.
A function reads the data header to get the total number of
bytes in the packet, and the sequence bytes. The rest of the
packet is then read. The data type, read from the common header,
is returned, determining the next step in the processing. One
of a number of different procedures is run to insert packet
data into the appropriate database tables. If the data type
returned is less than or equal to 0 an error message is
returned stating that the packet was not inserted.
The initialization of the ingestion process also sets up the
necessary connections to the SPICE kernel information
(Navigation and Ancillary Information Facility (NAIF) system
designed to provide scientists with ancillary observation
geometry data useful in interpretation of science instrument
observations returned from planetary spacecraft), the database,
and the input data. The appropriate SPICE kernels are loaded
and opened, and a connection is initiated with the database.
SPICE kernels are used to compute the local solar time of the
measurements from the spacecraft or instrument clock times.
As engineering values are entered into the database, stored
database procedures are called to convert raw engineering DN
values into physical units. The raw DN values are converted
using stored polynomials unique to each engineering parameter..
The polynomials were derived through hardware calibrations, see
the TEGA RDR SIS Appendix 7.3 for a table of the engineering
conversions.
Data
====
The TEGA RDR data set is composed of a series of date stamped
files that contain 1 day's worth (24 hours, 00:00:00 UTC to
23:59:59 UTC) of data for 4 different data types. The following
sections describe each data type.
SCRDR
-----
SC data are composed of scanning calorimeter data. These data
are composed of data collection time and oven and sheild
temperature and duty cycle data.
EGSRDR
------
EGSRDR data are mass spectrometer data collected in sweep
mode. These data are composed of timing, mass spectrometer
emission, temperature and voltage parameters, as well as
detector counts at each of the four detectors.
EGHRDR
------
EGHRDR data are mass hopping mode EGA data. These data
include start and stop times for the collection, voltage,
emission energy and level, and counts at the detector.
ENGRDR
------
Engineering data are composed of the 84 different engineering
readings monitored in TEGA. ENGRDR data is composed of
collection time information and engineering value. The
following is a list of all the engineering readings and a
description of each.
TA_MANIFOLD_PRES Manifold Pressure
TA_PLUS_5_VREF +5V REF
TA_OUTLET_PRES Outlet Pressure
TA_MANIFOLD_TEMP TA Manifold Temperature
TA_EGA_PLUMB_TEMP MS Plumbing Temperature
TA_EGA_BAKEOUT_TEMP Bakeout temperature
TA_PLUMBING_1_TEMP Plumbing 1 Temperature
TA_PLUMBING_2_TEMP Plumbing 2 Temperature
TA_EGA_MAN_TEMP MS Manifold Temperature
TA_CAL_TANK_TEMP Cal Tank Temperature
TA_CPU_TEMP CPU Temperature
TA_PWR_SPLY_1_TEMP Power Supply 1 Temperature
TA_PWR_SPLY_2_TEMP Power Supply 2 Temperature
TA_PWR_CNTL_1_TEMP Power Control 1 Temperature
TA_PWR_CNTL_2_TEMP Power Control 2 Temperature
TA_A2D_TEMP ADC Temperature
TA_COVER_1_TEMP cover 1 temperature
TA_INPUT_FUNNEL_1_LO_TEMP Funnel 1 Temperature
TA_PRES_SENSE_FD_BK Pres Sense Exc. Feedback
TA_INPUT_FUNNEL_2_LO_TEMP Funnel 2 Temperature
TA_OVEN_TEMP Oven Temperature
TA_SHLD_TEMP Shield Temperature
TA_EGA_ELECT_BOX_TEMP TEB Temperature
TA_T_HEATER_TEMP 'T' Heater Temperature
TA_TRANS_TUBE_TEMP Transfer Tube Temperature
TA_EGA_GEC_TEMP GEC Temperature
TA_BUS_A_VOLT Bus A Voltage
TA_AGD_0_1 AGD_0_3 ground
TA_AGD_3_1 AGD_3_1 ground
TA_CPU_PLUS_5_VOLT CPU Voltage
TA_ANLG_PLUS_12_VOLT Analog +12V Voltage
TA_ANLG_MINUS_12_VOLT Analog -12V Voltage
TA_OVEN_PLUS_15_VOLT Oven Voltage
TA_SHIELD_PLUS_30_VOLT Shield Voltage
TA_BUS_A_CUR Bus A Current
TA_BUS_B_CUR Bus B Current
TA_EGA_CUR EGA Current
TA_CPU_PLUS_5_CUR CPU Current
TA_ANLG_PLUS_12_CUR Analog +12V Current
TA_ANLG_MINUS_12_CUR Analog -12V Current
TA_OVEN_PLUS_15_CUR Oven Current
TA_SHIELD_PLUS_30_CUR Shield Current
TA_FULL_DETECT Full Detect Integrated
TA_FULL_DETECT_RAW Full Detect Raw
TA_OVEN_ERR Oven Error
TA_SHLD_ERR Shield Error
TA_CAL_TANK_COLD_TEMP Cal Tank Cold Temperature
TA_COVER_2_TEMP cover 2 Temperature
MEM_OVEN_INT_LO Oven integrator val lo bytes
MEM_OVEN_INT_HI Oven integrator val hi bytes
EM_SHLD_INT_LO Shield integrator val lo bytes
MEM_SHLD_INT_HI Shield integrator val hi bytes
MEM_OVEN_VOLT Oven voltage
MEM_OVEN_CUR Oven current
MEM_SHLD_VOLT Shield voltage
MEM_SHLD_CUR Shield current
MEM_MANIFOLD_PRES Manifold pressure
MEM_OVEN_ERR Oven error
MEM_SHLD_ERR Shield error
MEM_T_WIDTH T pulse width
COVER1_DONE Cover1 Limit Switch
COVER2_DONE Cover2 Limit Switch
MEM_OVEN_WIDTH Oven pulse width
MEM_SHLD_WIDTH Shield pulse width
EGA_STATUS_BITS Status bits value
EGA_TRAP_CUR Trap current monitor
EGA_EMISSION_CUR Emission current monitor
EGA_FILAMENT_1 Filament 1 in use
EGA_FILAMENT_2 Filament 2 in use
EGA_PLUS_5_VOLT +5 volt monitor
EGA_PLUS_12_VOLT +12 volt monitor
EGA_MINUS_12_VOLT -12 volt monitor
EGA_FILAMENT_CUR_1 Filament 1 current monitor
EGA_FILAMENT_CUR_2 Filament 2 current monitor
EGA_MULTIPLIER_VOLT Multiplier voltage monitor
EGA_ION_PUMP_VOLT Ion Pump voltage monitor
EGA_ION_PUMP_CUR Ion Pump Current monitor
EGA_SWEEP_VOLT Sweep voltage monitor
EGA_GEC_CUR GEC current monitor
EGA_MAGNET_TEMP_1 Magnet 1 temperature
EGA_MAGNET_TEMP_2 Magnet 2 temperature
EGA_PROC_TEMP CPU temperature
EGA_AVG_CALLS Average # calls to Task Queue
EGA_MIN_CALLS Minimum # calls to Task Queue
EGA_SPARE_3 Spare
EGA_SPARE_4 Spare
Ancillary Data
==============
No ancillary data are included with this data set.
Coordinate System
=================
Several coordinate systems are used by the Phoenix project. A
detailed description can be found in the TEGA RDR SIS document
found in the Documents directory.
Software
========
No TEGA specific software is provided with this data set.
PDS-labeled images and tables can be viewed with the program
NASAView, developed by the PDS and available for a variety of
computer platforms from the PDS web site
http://pds.nasa.gov/tools/software_download.cfm. There is no
charge for NASAView.
Media/Format
============
The TEGA RDR will be delivered using DVD media. Formats will be
based on standards for such products established by the
Planetary Data System (PDS) [PDSSR2001].
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