The Pulser Spectra, Command List, Message Log, E Kernel, Channelized, and Engineering data sets provide supporting information on the Gamma-Ray Spectrometer's commands, hardware status, and information used in spectral calibration routines. Each is briefly described below. For more detailed information on each of these types of data, see the EDR Dataset Description document.

Pulser Spectra

Pulser data are internal GS calibration data, used for data processing and correction. The Pulser Spectra data are time series records taken over the course of a day. Data files are labeled with the date. Individual records are a single data collection interval, which lasts approximately 20 seconds.

Command List

Command List data are records of the commands issued to the File Interchange System (FIS) for up-link to the spacecraft and executed by the CEB. The Command List data are time series records taken over the course of a day. Data files are labeled with the date. Individual records are a single data collection interval, which lasts approximately 20 seconds.

Message Log

The Message Log data are messages returned from the Gamma-Ray Spectrometer's Central Electronics Box (CEB). When the CEB receives a command, it either sends a reply equivalent to "I understand" or returns an error message. For this reason, this type of data is sometimes called "Message and Error" data as both are recorded. The Message Log data are time series records taken over the course of a day. Data files are labeled with the date. Individual records are a single data collection interval, which lasts approximately 20 seconds.

E Kernel Data

The E-Kernel, or Experiment Kernel, data consists of the Experimenter's Notes, the list of commands sent, and the associated timing information. These data are produced in response to a set of commands being placed on the File Interchange System (FIS).

The File Interchange System Tool is an automated process that allows a user to submit commands, files, and experiment kernels (E-Kernel) to the FIS for upload to the spacecraft and to the University of Arizona's GRS database for record keeping. The FIS tool uses JPL-supplied tools to create full Spacecraft Activity Sequence Files (SASFs) and place them in the FIS. It is command-line driven to allow batch processing and simple terminal access. A Graphical User Interface (GUI) is also available to allow browsing of input files and creation of the E-Kernel.

Channelized Data

Channelized Data are engineering data that may be changed only by JPL personnel for spacecraft controls. Some GRS engineering decisions depend on this type of data, but not vice versa. Channelized values are different than engineering values, below, in that they are recorded by the spacecraft computer and are received and processed by JPL, and then ingested into the University of Arizona's Gamma-Ray Spectrometer database.

Channelized data are time series records taken over the course of a day. Data files are grouped in the CHAN folder and are labeled with the channelized parameter name. Individual records are a single data collection interval, which is variable in duration. Channelized data values are reported by type, and contain the processed channelized value.

Engineering Data

Engineering Data are specific monitoring values recorded by the Gamma-Ray Spectrometer's Central Electronics Box (CEB). Engineering Data are records of temperatures and other parameters which are used to assess health of the gamma-ray spectrometer's instruments. These data are also used during the calibration of data to common energy scales.

The Engineering data are time series records for each engineering parameter taken over the course of a 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, raw value, and engineering value,

In general, temperatures are reported in Celsius, currents in amps, and potentials in volts. The ENG_DATA label file is the definitive source for the units of measure.

Overview of Uncalibrated Data

Uncalibrated data are raw data that has had associated timing and spatial information added. A full description and overview may be found in the 2001 Mars Odyssey Gamma Ray Spectrometer EDR NASA Level 0 Software Interface Specification (EDR SIS).