1 Purpose and Scope of Document

1.1 Purpose

This document will serve to provide users of the MESSENGER X-Ray Spectrometer (XRS) Experiment Data Record (EDR) data product with a detailed description of the XRS instrument, data product generation, validation and storage. The XRS EDR consists of an X-ray spectrometer measurement over a given area of the Mercury surface and a simultaneous measurement of the solar X-ray spectrum. Measurements are grouped together into a PDS binary table which consists of all measurements obtained over one earth day. Only XRS EDRs are addressed by this document. Higher level products, such as Calibrated Data Records (CDRs) or Reduced Data Records (RDRs) are addressed by the XRS RDR SIS document. This SIS will address the XRS EDR data product, the file transfer method from the MESSENGER Science Operations Center to PDS, and the format and content of the XRS EDR Volume Archive. The document is thus both an EDR data product SIS and an EDR archive volume SIS.

1.2 Scope

This Software Interface Specification (SIS) is useful to those who wish to understand the format and content of the XRS EDR data products. Typically, these individuals include scientists, data analysts, and software engineers. The SIS applies to EDR data products produced during the course of MESSENGER mission operations. Reduced Data Records and Calibrated Data Records (RDR and CDRs) are outside the scope of this SIS and are described in a separate SIS document – the XRS RDR SIS. RDRs and CDRs are also archived in their own, separate PDS archive volume.

2 Applicable Documents

The Messenger XRS SIS is responsive to the following Documents:

MESSENGER Mercury: Surface, Space Environment, Geochemistry, Ranging; A mission to Orbit and Explore the Planet Mercury, Concept Study, March 1999. Document ID number FG632/ 99-0479
Planetary Data System Standards Reference, Aug 1, 2003, Version 3.6. JPL D-7669, Part-2.
MESSENGER Data Management and Archiving Plan. The Johns Hopkins University, APL. Document ID number 7384-9019
[PLR] Appendix 7 to the discovery program Plan; Program Level Requirement for the MESSENGER Discovery project; June 20, 2001.
Instrument Calibration Report X-Ray Spectrometer

3 Relationships with Other Interfaces

The XRS EDR data products are stored on Hard Disk and in an SQL (Structured Query Language) relational databases for rapid mission access during mission operations. The data products will be electronically delivered to the PDS Geosciences Node according to the delivery schedule in the MESSENGER Data Management and Archiving Plan. The data in the EDR files themselves will be stored in a PDS BINARY TABLE object.

4 Roles and Responsibilities

The roles and responsibilities of the instrument teams, Applied Physics Lab (APL), Applied Coherent Technology (ACT), and the Planetary Data System (PDS) are defined in the MESSENGER Data Management and Archiving Plan.

5 Data Product Characteristics and Environment

5.1 Instrument Overview

The Mercury Surface, Space Environment, Geochemistry and Ranging (MESSENGER) mission is designed to orbit Mercury following one Earth flyby, two flybys of Venus and three of Mercury. It launched in August 2004 and will use these flybys to achieve an orbit insertion around Mercury in March 2011. Initial data collection will begin during the three flybys of Mercury, and will primarily consist of global mapping and measurements of the surface, atmosphere and magnetosphere composition. MESSENGER will remain in orbit for the rest of the nominal mission, which is scheduled to end in March 2012 [see the MESSENGER Data Management and Archiving Plan for extended mission updates]. Once in orbit around Mercury it will begin a series of observations using multiple instruments. These observations will provide data to answer questions about the nature and composition of Mercury’s crust, tectonic history, the structure of the atmosphere and magnetosphere, and the nature of the polar caps.

The X-Ray Spectrometer (XRS) experiment is comprised of three identical gas proportional counters (GPC) that measure X-rays emitted from the surface of Mercury in the energy range from about 1 to 10 keV. X-rays in this energy range sample the planetary surface to depths of a few tens of microns. The GPCs each have a 10-cm² active area and use both anti-coincidence wires and pulse shape discrimination to minimize background. Balanced filters are used to resolve the lower energy X-ray lines from Mg, Al, and Si. This technique has been used previously on other orbital X-ray experiments flown on the Apollo 15, 16 and NEAR-Shoemaker missions. One GPC has a thin aluminum filter, which filters out Si photons, one has a thin Mg filter, which filters out Al and Si photons, and the third GPC has no filter. The energy resolution of the gas counters is sufficient to resolve the higher energy lines from S, Ca, Ti, and Fe. A small Si-PIN detector is used as a solar monitor, because the Sun is the source of the planetary X-ray fluorescence. The field-of-view (FOV) of the GPCs is 12 degrees.

Both the GPCs and the Si-PIN detector count individual photons, producing an electronic pulse that is proportional to the energy of the absorbed photon. Each valid count is stored in energy histograms (spectra) that are 244 channels for the GPC and 231 channels for the Si-PIN. The accumulation time for these histograms will vary depending upon proximity to the planet. At periapsis the accumulation time will be 40 seconds and at apoapsis 450 seconds.

The XRS is comprised of three physical units. The GPCs make up the Mercury X-ray Unit (MXU). The Solar Assembly for X-rays (SAX) includes the Si-PIN diode, preamplifier, shaping electronics and thermal electric cooler (TEC). The analog and digital electronics are contained in the Main Electronics for X-rays (MEX) unit. The SAX is located at the “top center” edge of the solar shield (see Figure 1). The MXU and MEX are co-located within the payload adapter ring.

Figure 1 XRS Configuration on MESSENGER

5.2 Data Product Overview

This SIS document only contains information on the XRS Experiment Data Record (EDR) data product. Please refer to the Calibrated Data Record (CDR) SIS and Reduced Data Record (RDR) SIS for documentation on higher level XRS products.

There are two data products for the XRS EDR archive. One is the MESSENGER X-Ray Spectrometer EDR. This is the primary data product. The other is the XRS Command Echo EDR. This document will refer to the two types by their standard data product id. “XRSEDR” for the XRS spectral data and “XRS COMMAND ECHO” for the command echo data. Each EDR product consists of 2 files. One file contains the data itself. The XRSEDR data are arranged in binary table format while the XRS COMMAND ECHO data are stored in ASCII table format. The other file is a label file, which describes the content of the data file. The label file defines the start time and end of the observation, product creation time, etc. The PDS label file contains a reference pointer to a separate format file. The format file describes the structure of the table in the data file and each of the different fields within the table. This format file resides in LABEL directory of the data archive volume. Each EDR data product will contain all observations collected or command echos generated by the instrument on a given Earth day.

5.3 Data Processing

5.3.1 Data Processing Level

There will be one XRS EDR data volume archive. The volume archive will contain CODMAC (Committee on Data Management and Computation) level 2 data products, also known as EDRs. Each product will have a unique file name and conform to the file naming convention in section 6.3. All EDR products will be stored at the APL Science Operations Center (SOC). Data downlink is telemetered through NASA’s Deep Space Network (DSN) managed by the Jet Propulsion Laboratory in Pasadena, CA, and then forwarded to the APL Mission Operations Center (MOC). The MOC then sends telemetry in the form of CCSDS packets to the SOC. Level 1 CODMAC XRS data is extracted from the CCSDS packets and stored in a database and file system at the SOC. Periodic automatic execution of the ‘PIPE-XRS2EDR’ software will then generate the EDRs.

5.3.2 Data Product Generation

The X-Ray Spectrometer EDR files will be produced by the MESSENGER Science Operations Center (SOC) operated jointly by APL and ACT. The ‘PIPE-XRS2EDR’ software creates EDR data in the PDS labeled format specified by this SIS. The EDR data products are made available to the MESSENGER Science Team for initial evaluation and validation. At the end of the evaluation and validation period, the data are organized and stored in the directory structure described in section 6.5 for transmittal to the PDS Geosciences node. The transmittal process is described in the following section, Data Flow. The initial and subsequent releases to PDS are according to the schedule table in the MESSENGER Data Management and Archiving Plan. PDS will then provide public access to the data products via its online distribution system.

5.3.3 Data Flow

The MESSENGER SOC operates under the auspices of the MESSENGER Project Scientist to plan data acquisition and generate and validate data archives. The SOC supports and works with the MOC, The Science Team, instrument scientists, and the PDS.

Figure 2 MESSENGER Data Flow shows the flow of data within the MESSENGER project and out to PDS. The MOC handles raw data flow to and from the MESSENGER spacecraft and the SOC converts the raw telemetry into EDRs. The Science Team validates the EDRs and notifies the SOC if corrections are needed. Documentation and EDRs are delivered to the PDS Geosciences node. SPICE Kernels are delivered to the PDS Navigation and Ancillary Information (NAIF) node.

The MESSENGER SOC will deliver data for the XRS EDR data volume in standard product packages. Each package will comprise data and ancillary data files, organized into directory structures consistent with the volume design described in section 6.5.

Figure 2 MESSENGER Data Flow

The following describes the electronic transfer process of releasing data to PDS for the first PDS delivery. Future data deliveries will be assumed to follow the same process unless otherwise noted in an update of this document. Given the long duration of the mission the project is reserving the option of exploring alternate data delivery methods for subsequent deliveries. As such, the method of electronic transfer may change and will be revised accordingly in the SIS. Any changes to the delivery process will be noted in an update to the SIS document and will include the specific dates which will use the new delivery process. The delivery of products to the data volume will follow the schedule in the MESSENGER Data Management and Archiving Plan

In the week prior to the delivery date the directory structure will be compressed into a single “zip archive” file for transmittal to the PDS node. The zip archive preserves the directory structure internally so that it can be recreated after electronic delivery to the PDS node. The zip archive file is transmitted to the PDS node via FTP to an account set up by the receiving node. Also transmitted will be a checksum file created using the MD5 algorithm. This provides an independent method of verifying the integrity of the zip file after it has been sent. Within days of transmittal the PDS node will acknowledge receipt of the archive and checksum file. If acknowledgement is not received, or if problems are reported, the MESSENGER SOC will immediately take corrective action to effect successful transmittal.

After transmittal the PDS node will uncompress the zip archive file and check for data integrity using the checksum file. The node will then perform any additional verification and validation of the data provided and will report any discrepancies or problems to the MESSENGER SOC. It is expected that the node will perform these checks in about two weeks. After inspection has been completed to the satisfaction of the PDS node, the node will issue to the MESSENGER SOC acknowledgement of successful receipt of the data.

Following receipt of a data delivery the PDS node will organize the data into a PDS volume archive structure within its online data system. Newly delivered data will be made available publicly from PDS once accompanying labels and other documentation have been validated.

5.3.4 Labeling and Identification

For every X-Ray data file there exists a PDS Label file. The label file conforms to PDS version 3.6 standards. Consult the PDS Standards Reference Document for more information on this standard. The PDS label describes the data product and provides ancillary information about the data product. The label file is detached and separate from the data file which contains the data in a PDS binary table. The following is an example of the contents of the XRSEDR PDS label file. Details about the label format are specified later in section 6.4.

PDS_VERSION_ID = "PDS3"

/*** FILE FORMAT ***/

FILE_RECORDS = 130

RECORD_TYPE = FIXED_LENGTH

RECORD_BYTES = 2258

/*** GENERAL DATA DESCRIPTION PARAMETERS ***/

PRODUCT_ID = "XRS2006018_DAT"

PRODUCT_VERSION_ID = "V1"

PRODUCT_CREATION_TIME = 2006-08-30T21:26:05

PRODUCT_TYPE = "DATA"

STANDARD_DATA_PRODUCT_ID = "XRSEDR"

SOFTWARE_NAME = "PIPE-XRS2EDR"

SOFTWARE_VERSION_ID = "1.0"

INSTRUMENT_HOST_NAME = "MESSENGER"

INSTRUMENT_NAME = "XRAY SPECTROMETER"

INSTRUMENT_ID = "XRS"

DATA_SET_ID = "MESS-E/V/H-XRS-2-EDR-RAWDATA-V1.0"

MISSION_PHASE_NAME = "VENUS 1 CRUISE"

TARGET_NAME = "CALIBRATION"

START_TIME = 2006-01-18T13:13:57

STOP_TIME = 2006-01-18T23:58:56

SPACECRAFT_CLOCK_START_COUNT = "46077252"

SPACECRAFT_CLOCK_STOP_COUNT = "46115952"

^TABLE = "XRS2006018.DAT"

OBJECT = TABLE

COLUMNS = 175

INTERCHANGE_FORMAT = BINARY

ROW_BYTES = 2258

ROWS = 130

DESCRIPTION = "

This table contains X-ray spectra and associated instrument

parameters, as observed by the MESSENGER X-Ray Spectrometer (XRS).

Detailed descriptions for the parameters defined below are contained

in the EDR SIS document.

The complete column definitions are contained in an external file

found in the LABEL directory of the archive volume.

^STRUCTURE = "XCOLUMN.FMT"

END_OBJECT = TABLE

END

Notice that the external format file, “XCOLUMN.FMT”, defines the structure of the binary table. The table structure is detailed in APPENDIX: XCOLUMN.FMT File.

The following is an example of the XRS Command Echo label file.

PDS_VERSION_ID = "PDS3"

/*** FILE FORMAT ***/

FILE_RECORDS = 20

RECORD_TYPE = FIXED_LENGTH

RECORD_BYTES = 125

/*** GENERAL DATA DESCRIPTION PARAMETERS ***/

PRODUCT_ID = "XRS_CMD2009274_TAB"

PRODUCT_VERSION_ID = "V1"

PRODUCT_CREATION_TIME = 2009-10-01T20:47:23

PRODUCT_TYPE = "ANCILLARY"

STANDARD_DATA_PRODUCT_ID = "XRS_COMMAND_ECHO"

SOFTWARE_NAME = "PIPE-XRS2EDR"

SOFTWARE_VERSION_ID = "1.1"

INSTRUMENT_HOST_NAME = "MESSENGER"

INSTRUMENT_NAME = "XRAY SPECTROMETER"

INSTRUMENT_ID = "XRS"

DATA_SET_ID = "MESS-E/V/H-XRS-2-EDR-RAWDATA-V1.0"

MISSION_PHASE_NAME = "MERCURY 3 FLYBY"

TARGET_NAME = "MERCURY"

START_TIME = 2009-10-01T13:09:18

STOP_TIME = 2009-10-01T13:10:58

SPACECRAFT_CLOCK_START_COUNT = 162890024

SPACECRAFT_CLOCK_STOP_COUNT = 162890124

^TABLE = "XRS_CMD2009274.TAB"

OBJECT = TABLE

COLUMNS = 7

INTERCHANGE_FORMAT = ASCII

ROW_BYTES = 125

ROWS = 20

DESCRIPTION = "

This table contains one set of the commands executed by the MESSENGER

X-Ray Spectrometer (XRS). A set is defined as all data with timestamps

corresponding to a given Earth day. The complete column definitions are

contained in an external structure file found in the LABEL directory of

the archive volume. Additional details are contained in the EDR SIS

document.

^STRUCTURE = "XRS_CMDECHO.FMT"

END_OBJECT = TABLE

END

Notice that the external format file, “XRS_CMDECHO.FMT”, defines the structure of the ASCII table. The table structure is detailed in APPENDIX: XRS_CMDECHO.FMT file.

5.4 Standards Used in Generating Data Products

5.4.1 PDS Standards

The XRS EDR data products comply with the Planetary Data System standards for file formats and labels, as specified in the PDS Standards Reference. The EDR data products include:

A Binary or ASCII Table object (the primary data),
Label File - serves as a high-level description of the parameters of which correspond to the Table object.

· a pointer to a FORMAT file which describes the structure of the table

5.4.2 Time Standards

The MET field in the XRS EDR binary table matches the spacecraft time in integer seconds that is transmitted to MESSENGER subsystems by the Integrated Electronics Module (IEM). This is referred to by the MESSENGER project as Mission Elapsed Time (MET). MET = 0 is August 3, 2004, at 05:59:16 UTC, which is 1000 seconds prior to the MESSENGER launch. Relativistic effects and circumstances occurring during the mission would result in MET not being a true account of seconds since launch. Following a planned spacecraft clock reset[1] on January 8, 2013, partition numbers (1/, or 2/) were added to product labels to disambiguate MET seconds after the spacecraft clock reset (if partition number is not present, SPICE defaults to partition 1/). For this reason the MESSENGER spacecraft clock coefficients file is archived at the PDS Navigation and Ancillary Information Facility (NAIF) Node. This file is used in conjunction with the leapseconds kernel file in order to calculate the conversion between MET and UTC.

The conversion is easily done through the use of SPICE kernels and the CHRONOS Utility. CHRONOS is a utility included with the SPICE package that is distributed by the PDS NAIF node. The SPICE kernels are files that contain the information needed to perform the conversion. Two SPICE kernels are required. One is the Leapseconds Kernel (LSK) and the other is the MESSENGER Spacecraft Clock Kernel (SCLK). The SCLK file is used by CHRONOS to convert between spacecraft clock time and ephemeris time, while the LSK file is used to convert from ephemeris time to UTC time. The CHRONOS utility is self-documenting and the SPICE package itself contains full documentation on each of the utilities (including CHRONOS) and how they are used.

5.4.3 Coordinate Systems

The following lists the computational assumptions for the geometric and viewing data provided in the PDS label. There are two coordinate systems in use: 1) the celestial reference system used for target and spacecraft position and velocity vectors, and camera pointing; and 2) the planetary coordinate system for geometry vectors and target location. The celestial coordinate system is J2000 (Mean of Earth equator and equinox of J2000). The planetary coordinate system is planetocentric.

COMPUTATIONAL ASSUMPTIONS

· The mid-point time of observation is used for the geometric element computations.

· Label parameters reflect observed, not true, geometry. Therefore light-time and stellar aberration corrections are used as appropriate.

· The intertial reference frame is J2000 (also called EME2000).

· Latitudes and longitudes are planetocentric.

· Distances are in km, speeds are in km/sec, angles are in degrees, angular rates are in degrees/sec, unless otherwise noted.

· Angle ranges are 0 to 360 degrees for azimuths and local hour angle. Longitudes range from 0 to 360 degrees (positive to the East). Latitudes range from –90 to 90 degrees.

5.4.4 Data Storage Conventions

The data are organized following PDS standards and stored on hard disk and in a SQL (Structured Query Language) database for rapid access during mission operations. The MESSENGER SOC will transfer data to PDS via electronic transfer and delivery methods as detailed in section 5.3.3. After verification of the data transfer PDS will provide public access to MESSENGER science data products through its online data distribution system.

5.5 Data Validation

The XRS EDR data products will be validated by the XRS Instrument scientist for science content and for compliance with PDS archive standards [MESSENGER Data Management and Archiving Plan].

6 Detailed Data Product Specifications

6.1 Data Product Structure and Organization

The MESSENGER XRS EDR data set will be archived at the PDS Geosciences node as a data archive volume. The XRS EDR products in the data archive volume are intended to store the data in a form closest to the raw telemetry data received from the spacecraft. The automated production and release of the EDRs will follow the release schedule in the MESSENGER Data Management and Archiving Plan. If errors are discovered the data will be replaced with corrected EDRs on the next scheduled delivery date.

6.1.1 Handling Errors

The possibility exists that errors may be introduced into the archive even with validation procedures applied to the archive volumes. An ERRATA report file is maintained to track and document all discovered uncorrectable errors that may occur during the mission. Correctable errors, such as revised EDRs or EDRs that were missing from a previous PDS delivery will be provided at the next scheduled PDS delivery or at the final delivery date (see schedule in the MESSENGER Data Management and Archiving Plan). PDS will then replace the outdated files with the revised EDR files in the data directories of the archive volume. The ERRATA report file is archived in the ROOT directory of the XRS EDR data volume.

6.1.2 Geometric Elements

The geometric elements are an essential part of the archive; they contain the data and information to characterize the geometric properties of the sensor, and to fully describe the viewing geometry of an observation. These data are essential to geodetic, cartographic, and photometric applications.

The geometric elements are organized according to the SPICE kernel concepts adopted by the Navigational Ancillary Information Facility (NAIF) at the Jet Propulsion Laboratory. SPICE is an acronym for Spacecraft, Planet, Instrument, C-matrix, and Event kernels. The SPICE kernel data set will be stored in ancillary data volumes at the PDS NAIF Node.

6.2 Data Format Description

Data is stored in binary table format. A detached PDS format file will provide a detailed description of the structure of the binary table.

6.3 File Naming Conventions

The general form of the XRSEDR file name is "XRSYYYYDOY.DAT", where:

XRS instrument identifier: represents the XRS instrument

YYYY The four digit year corresponding to the MET for each record in the EDR.

DOY The three digit day of year corresponding to the MET for each record in the EDR.

.DAT the file extension will always be the three character

mnemonic ‘DAT’, indicating data stored in binary format.

The PDS label will have the same naming convention but with the file extension .LBL.

The command echo EDRs will have a separate file naming convention to distinguish themselves from the science data. The general form of the XRS Command Echo EDRs is “XRS_CMDYYYYDOY.TAB” where:

XRS_CMD indicates the file contains XRS command echo data.

YYYY The four digit year corresponding to the MET for each record in the EDR.

DOY The three digit day of year corresponding to the MET for each record in the EDR.

.TAB the file extension indicating the data is stored in ASCII format.

6.4 Label and Header Description

6.4.1 PDS Label File Format

The following are the keyword definitions for the detached PDS label file. The detached PDS label file has the same name as the data file it describes, except for the extension .LBL to distinguish it as a label file.

PDS_VERSION_ID

Represents the version number of the PDS standards documents that is valid when a data product label is created. PDS3 is used for the Messenger Data products.

FILE_RECORDS

The file_records element indicates the number of physical file records, including both label records and data records.

RECORD_TYPE

The record_type element indicates the record format of a file. The FIXED_LENGTH value is appropriate for the BINARY table object used for the MESSENGER XRS EDR data products.

RECORD_BYTES

This element indicates the number of bytes in a physical file record, including record terminators and separators.

PRODUCT_ID

The product_id data element represents a permanent, unique identifier assigned to a data product by its producer. See also: source_product_id.

Note: In the PDS, the value assigned to product_id must be unique within its data set.

PRODUCT_VERSION_ID

Identifies the version of the product, represented initially by “V1”. The version number will be incremented if the product needs to be regenerated as a result of a correction of the data or as a result of a change in the method used to create the product.

PRODUCT_CREATION_TIME

Stores the time that the data product was created, in UTC time.

PRODUCT_TYPE

The XRS EDR contains science data, hence the value is always “DATA”.

STANDARD_DATA_PRODUCT_ID

The XRS EDR files are identified as belonging to the same standard data product via this ID.

SOFTWARE_NAME

Identifies the name of the software system creating the data products.

SOFTWARE_VERSION_ID

The version number of program or program library used by the instrument to collect observations.

INSTRUMENT_HOST_NAME

Identifies the MESSENGER spacecraft on which the instrument is located.

INSTRUMENT_NAME

The full, unabbreviated name of the instrument.

INSTRUMENT_ID

The project abbreviation of the instrument.

DATA_SET_ID

Uniquely identifies the EDR file as part of a volume collection.

MISSION_PHASE_NAME

Identifies the project designation of the mission phase associated with the data product.

TARGET_NAME

The target of the observation.

START_TIME

The start time of the observation.

STOP_TIME

The time when the instrument stopped collecting measurements.

SPACECRAFT_CLOCK_START_COUNT

Clock count of the spacecraft computer at the start of the observation.

SPACECRAFT_CLOCK_STOP_COUNT

Clock count of the spacecraft computer at the end of the observation.

^TABLE

Identifies the name of the EDR file which contains the data in BINARY table format. The structure of the data file is defined in a referenced format file.

^STRUCTURE

This is a pointer to the external file which provides the structure definition for the table object.

6.4.2 Binary Table File Formats

Each XRS PDS label will contain a pointer to the XCOLUMN.FMT file. This file describes the structure of the XRS binary table. This includes column name, byte size, data type, applicable units, and a description of the value assigned to the column. The full XCOLUMN.FMT file is shown in section 8.1 Appendix: XCOLUMN.FMT file.

6.4.3 ASCII Table File Formats

Each XRS COMMAND ECHO PDS label will contain a pointer to the XRS_CMDECHO.FMT file. This file describes the structure of the XRS ASCII table. This includes column name, byte size, data type, applicable units, and a description of the value assigned to the column. The full XRS_CMDECHO.FMT file is shown in the Appendix.

6.4.4 Format File Keyword Definitions

The following describes the keywords used in the format files:

OBJECT

Identifies the object as a column field within a binary table.

NAME

Indicates a literal value representing the common term used to identify an element or object. NOTE: in the PDS data dictionary, name is restricted to 30 characters and must conform to PDS nomenclature standards.

COLUMN_NUMBER

Identifies the location of the column within the larger table data object. For tables consisting of rows (I= 1, N) and columns (j = 1, M) the column_number is the j-th index of any row.

BYTES

Specifies the total number of bytes allocated for this particular column element.

DATA_TYPE

Specifies the internal representation and/or mathematical properties of the value being stored in this column.

START_BYTE

Identifies the location of the first byte of the particular column, counting from 1.

DESCRIPTION

Describes the value(s) stored in the column object.

ITEMS

This keyword is used for columns containing spectra values, such as column 175 in the XRS EDR binary table. Defines the number of multiple, identical occurrences of a single data item. For example, in column 175 there are 244 items which correspond to channels 10-253 in the detector.

ITEM_BYTES

This keyword is used for columns containing spectra values, such as column 175 in the XRS EDR binary table. Represents the size of each individual item within the column field. For example, in column 175 each item is a 2-byte integer.

6.5 Directory Structure and Contents for XRS EDR Data Archive Volume

The following illustration shows the directory structure overview for the XRS EDR Data Archive Volume. This volume contains the XRS EDR data products, supporting documentation, and any additional files required for the volume to be compliant with PDS standards. The content of the volume is expected to be updated with periodic releases according to the schedule in the MESSENGER Data Management and Archiving Plan. Revised EDRs (if needed) will also be delivered according to the same schedule. Revised EDRs will have an incremented version number in the PDS label.

Directory Structure Overview

<ROOT>

___________________________________|____________________

| | | | | |

|_____________________________________

| | |

|___________

| |

<2004> <2005>

|_______________

| | |

6.5.1 Directory Contents

<ROOT> Directory

This is the top-level directory of the data volume. The following are files contained in the root dirctory.

AAREADME.TXT - General information file. Provides users with information about the MESSENGER XRS data products. Directs user to other documents on the volume containing more detailed information.

VOLDESC.CAT - PDS file containing the VOLUME object. This gives a high-level description of the contents of the volume. Information includes: production date, producer name and institution, volume ID, etc.

ERRATA.TXT - Text file for identifying and describing errors and/or anomalies found in the current volume, and possibly previous volumes of a set. Any known errors for the associated volume will be documented in this file. This includes revised EDRs meant to replace EDRs in a previous PDS delivery.

<DOCUMENT> Directory

This subdirectory contains the documentation that will be needed in order to understand and analyze the EDR data products. Multiple copies of each document will be stored, each one in a different format. Files will be stored in PDF, ASCII, and HTMLformat.

DOCINFO.TXT – Identifies and describes the function of each file in the DOCUMENT directory.

<CATALOG> Directory

This subdirectory contains the catalog object files for the entire volume. The following files are included in the catalog subdirectory.

CATINFO.TXT: Identifies and describes the function of each file in the catalog directory.

DATASET.CAT: Describes the general content of the data set and includes information about the duration of the mission and the person or group responsible for producing the data.

INSTRUMENT.CAT: Describes physical attributes of the XRS instrument and provides relevant references to published literature.

INSTRUMENT_HOST.CAT: Describes the MESSENGER spacecraft.

MISSION.CAT: Describes the scientific goals and objectives of the MESSENGER program. It also identifies key people and institutions.

PERSON.CAT: Lists key XRS instrument personnel and their contact information.

REF.CAT: Contains full references for citations given in other documents.

<INDEX> Directory

This subdirectory contains the indices for the XRS EDR data products. The following files are contained in the index subdirectory.

INDXINFO.TXT – Identifies and describes the function of each file in the index subdirectory. This includes a description of the structure and contents of each index table in the subdirectory AND usage notes.

INDEX.TAB - The EDR index file is organized as a table: there

is one entry for each of the data files included in the XRS data set; the columns contain parameters that describe the observation as well as instrument and spacecraft parameters.

INDEX.LBL - Detached PDS label for INDEX.TAB.

MD5.TAB: Contains MD5 checksums for all files in the archive volume.

MD5.LBL: Detached PDS label for the MD5.TAB file.

<LABEL> Directory

This subdirectory contains format files referenced in the EDR PDS labels.

XCOLUMN.FMT: The format file that describes the binary Table object which stores the data in the XRS EDR.

XRS_CMDECHO.FMT: The format file that describes the text Table object which stores the command echo EDRs.

<Geometry> Directory

This subdirectory contains information about the SPICE kernel files needed to determine the observation geometry for the data.

GEOMETRY.TXT : Identifies and describes the SPICE kernels that a user must have in order to determine observation geometry for the data. The SPICE kernel files are archived with the PDS NAIF node.

<DATA> - Data Directory

This is the top level directory containing the EDRs. The data directories are organized by mission phase, followed by year, and month in UTC. The EDRs are contained in the month folders.

7 Release of Archives to PDS

The MESSENGER XRS EDR archive will be transferred from the SOC to the Planetary Data System Geosciences Node using the electronic transfer process detailed in section 5.3.3. The transfer will take place according to the schedule in the MESSENGER Data Management and Archiving Plan.

Table 1. Schedule of Data Releases by Mission Phase – REMOVED – refer to release schedule in MESSENGER Data Management and Archiving Plan.

8 Appendicies

8.1 APPENDIX: XCOLUMN.FMT File

The following is the full content of the XCOLUMN.FMT file. This file describes the binary table fields that will be contained in the XRSEDR binary table along with the byte size, data type, and a brief description of each field.

/* Table Structure for XRS EDRs */

NOTE = "An XRS flight software upload was implemented on 2007-08-17 UTC

which affects COLUMN 40 of the XRS EDR binary table. Prior to 2007-08-17,

column 40 was named LVPS_SPARE2 and was a spare, unused data column. On

and after 2007-08-17 the column is used to indicate the SAX_TEMP_MODE."

OBJECT = COLUMN

NAME = MET

COLUMN_NUMBER = 1

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 1

DESCRIPTION = "Time tag in seconds."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = ORBIT_NUMBER

COLUMN_NUMBER = 2

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 5

DESCRIPTION = "Orbit number is a unique identifier for a given

orbit of the MESSENGER spacecraft around Mercury. Orbit number is

defined as starting at apoherm and is calculated using the MET value

and the appropriate SPICE kernels. Orbit numbering does not start

until MESSENGER performs the Mercury orbit insertion. Until that time

the value for orbit number is 0."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = STATUS_INTERVAL

COLUMN_NUMBER = 3

BYTES = 2

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 9

DESCRIPTION = "Time period (in seconds) between status packets."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = SC_RANGE

COLUMN_NUMBER = 4

BYTES = 2

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 11

DESCRIPTION = "+Z range to Mercury surface. =65535 N/A."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = SC_ANGLE

COLUMN_NUMBER = 5

BYTES = 2

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 13

DESCRIPTION = "+Z angle to Mercury surface. =65535 N/A."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = DATA_QUALITY

COLUMN_NUMBER = 6

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 15

DESCRIPTION = "Integer representation of a 32-bit array. Each bit

represents a data quality flag. Currently only the least

significant bit is being used. Other bit positions will be

designated during the course of the mission as more data quality

parameters are identified by the instrument team. =1, the actual

data length in bytes does not match the reported length. =0, actual

data length in bytes matches reported length."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = SW_VERSION

COLUMN_NUMBER = 7

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 19

DESCRIPTION = "Software version number."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = ALARM_ID

COLUMN_NUMBER = 8

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 20

DESCRIPTION = "Latest alarm ID."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = ALARM_TYPE

COLUMN_NUMBER = 9

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 21

DESCRIPTION = "Latest alarm type. =0 persistent, =1 transient."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = ALARM_COUNT

COLUMN_NUMBER = 10

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 22

DESCRIPTION = "Count of number of alarms."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = CMD_EXECUTED

COLUMN_NUMBER = 11

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 23

DESCRIPTION = "Number of commands executed."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = CMD_REJECTED

COLUMN_NUMBER = 12

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 24

DESCRIPTION = "Number of commands rejected."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = MONITOR_RESPONSE

COLUMN_NUMBER = 13

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 25

DESCRIPTION = "Monitor response. =0 disabled, =1 enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = MEM_WRITE_ENABLE

COLUMN_NUMBER = 14

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 26

DESCRIPTION = "Memory write enable. =0 disabled, =1 enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = MACRO_LEARN_MODE

COLUMN_NUMBER = 15

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 27

DESCRIPTION = "Macro learn mode. =0 not learning, =1 learning."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = SPARE

COLUMN_NUMBER = 16

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 28

DESCRIPTION = "Spare column for possible future use."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = SCIENCE_RECORD_VERSION

COLUMN_NUMBER = 17

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 29

DESCRIPTION = "Version of science packet format."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = MACRO_ID

COLUMN_NUMBER = 18

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 30

DESCRIPTION = "ID of most recent macro executed."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = MACROS_REJECTED

COLUMN_NUMBER = 19

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 31

DESCRIPTION = "Number of macro commands rejected."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = MACROS_EXECUTED

COLUMN_NUMBER = 20

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 32

DESCRIPTION = "Number of macro commands executed."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = MACRO_BLOCKS

COLUMN_NUMBER = 21

BYTES = 2

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 33

DESCRIPTION = "Number of macro blocks free."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_SAFING_LEVEL

COLUMN_NUMBER = 22

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 35

DESCRIPTION = "The safing level set for the GPC1-MG detector.

=0 level zero or nominal level safing; the software will monitor the

planetary detector for the conditions which necessitate a higher

level of safing.

=1 level 1 safing; the HVPS voltage level for the affected sensor is

ramped down to 0 at a rate of 100 V/sec.

=2 level 2 safing; the software turns off analog power to the

affected sensor and turns off the associated HVPS. No further

attempts are made to restore the level-two-safed sensor to nominal

safing. The software waits for ground command to reset the affected

HVPS voltage levels."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_SAFING_RETRY

COLUMN_NUMBER = 23

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 36

DESCRIPTION = "The max number of retry attempts to reset the

GPC1-MG detector to level 0 safing."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_SAFING_LEVEL

COLUMN_NUMBER = 24

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 37

DESCRIPTION = "The safing level set for the GPC2-AL detector.

=0 level zero or nominal level safing; the software will monitor the

planetary detector for the conditions which necessitate a higher

level of safing.

=1 level 1 safing; the HVPS voltage level for the affected sensor is

ramped down to 0 at a rate of 100 V/sec.

=2 level 2 safing; the software turns off analog power to the

affected sensor and turns off the associated HVPS. No further

attempts are made to restore the level-two-safed sensor to nominal

safing. The software waits for ground command to reset the affected

HVPS voltage levels."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_SAFING_RETRY

COLUMN_NUMBER = 25

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 38

DESCRIPTION = "The max number of retry attempts to reset the

GPC2-AL detector to level 0 safing."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_SAFING_LEVEL

COLUMN_NUMBER = 26

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 39

DESCRIPTION = "The safing level set for the GPC3-UNfiltered (UN)

detector.

=0 level zero or nominal level safing; the software will monitor the

planetary detector for the conditions which necessitate a higher

level of safing.

=1 level 1 safing; the HVPS voltage level for the affected sensor is

ramped down to 0 at a rate of 100 V/sec.

=2 level 2 safing; the software turns off analog power to the

affected sensor and turns off the associated HVPS. No further

attempts are made to restore the level-two-safed sensor to nominal

safing. The software waits for ground command to reset the affected

HVPS voltage levels."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_SAFING_RETRY

COLUMN_NUMBER = 27

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 40

DESCRIPTION = "The max number of retry attempts to reset the

GPC3-UN detector to level 0 safing."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = DISCARDED_PACKET_COUNTER

COLUMN_NUMBER = 28

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 41

DESCRIPTION = "Number of calls to send-pkt that resulted in a

return value of false."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = TEC_LOSS_OF_CONTROL

COLUMN_NUMBER = 29

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 42

DESCRIPTION = "TEC loss of control flag. =0 no loss of control,

=1 loss of control."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = SOLAR_FLARE_DETECTED

COLUMN_NUMBER = 30

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 43

DESCRIPTION = "Solar flare detection flag. =0 no solar flare

detected, =1 flare detected."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = FLARE_HANDLING_ENABLED

COLUMN_NUMBER = 31

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 44

DESCRIPTION = "Solar flare handling enabled flag, software checks

this value upon detection of a solar flare. =0 do not handle solar

flare detection. =1 continue algorithm for handling solar flare

detection (see SOLAR_FLARE_ENACT)."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = FLARE_HANDLING_ENACTED

COLUMN_NUMBER = 32

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 45

DESCRIPTION = "Solar flare handling enacted flag. Allows software

to determine if solar flare handling has already been enacted or

whether this is a new detection of a solar flare. Only checked if

solar flare handling has been enabled (see previous field).

=0 the software sets it to true, starts the sf-time-enactable-left

counter out at sf-max-time-enactable, sets a flag telling the 1Hz

process to end the current integration and reporting period

immediately, and returns control to the 1Hz process.

=1 , the software decrements the sf-time-enactable-left counter and

checks its value. If sf-time-enactable-left is still greater than

0, the algorithm does nothing further. If sf-time-enactable-left

has reached 0, the algorithm starts the sf-timeout-left counter out

at sf-timeout-period and sets the sf-handling-enacted-now flag to

false."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = SENSOR_CONFIG_CHANGED

COLUMN_NUMBER = 33

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 46

DESCRIPTION = "Flag showing whether sensor configuration has

changed. =0 no change, =1 change."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = LVPS_PLUS_5V

COLUMN_NUMBER = 34

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 47

DESCRIPTION = "LVPS +5 volt monitor."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = LVPS_MINUS_5V

COLUMN_NUMBER = 35

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 48

DESCRIPTION = "LVPS -5 volt monitor."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = LVPS_PLUS_12V

COLUMN_NUMBER = 36

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 49

DESCRIPTION = "LVPS +12 volt monitor."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = LVPS_MINUS_12V

COLUMN_NUMBER = 37

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 50

DESCRIPTION = "LVPS -12 volt monitor."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = LVPS_SPARE0

COLUMN_NUMBER = 38

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 51

DESCRIPTION = "Spare unused column for LVPS monitoring."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = LVPS_SPARE1

COLUMN_NUMBER = 39

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 52

DESCRIPTION = "Spare unused column for LVPS monitoring."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = SAX_TEMP_MODE

COLUMN_NUMBER = 40

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 53

DESCRIPTION = "SAX Warmer temperature control mode.

=0 SAX off, =1 SAX on, =2 SAX Software Control."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = SOFTWARE_SUB_VERSION

COLUMN_NUMBER = 41

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 54

DESCRIPTION = "Sub-version of flight software."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = I2C_BUS_ERROR_COUNT

COLUMN_NUMBER = 42

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 55

DESCRIPTION = "I2C bus error count."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = LVPS_PLUS_5_I

COLUMN_NUMBER = 43

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 56

DESCRIPTION = "LVPS +5V current."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = LVPS_MINUS_5_I

COLUMN_NUMBER = 44

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 57

DESCRIPTION = "LVPS -5V current."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = LVPS_PLUS_12_I

COLUMN_NUMBER = 45

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 58

DESCRIPTION = "LVPS +12V current."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = LVPS_MINUS_12_I

COLUMN_NUMBER = 46

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 59

DESCRIPTION = "LVPS -12V current."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = LVPS_TEMP

COLUMN_NUMBER = 47

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 60

DESCRIPTION = "LVPS temperature."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = LVPS_PRIMARY_I

COLUMN_NUMBER = 48

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 61

DESCRIPTION = "LVPS primary current."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = LVPS_SWITCHED_PRIMARY_I

COLUMN_NUMBER = 49

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 62

DESCRIPTION = "LVPS switched primary current."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_PLUS_5V

COLUMN_NUMBER = 50

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 63

DESCRIPTION = "GPC1-MG +5 volt monitor."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_PLUS_5V

COLUMN_NUMBER = 51

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 64

DESCRIPTION = "GPC2-AL +5 volt monitor."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_PLUS_5V

COLUMN_NUMBER = 52

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 65

DESCRIPTION = "GPC3-UN +5 volt monitor."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = SAX_PLUS_5V

COLUMN_NUMBER = 53

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 66

DESCRIPTION = "SAX +5 volt monitor."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = ANALOG_PLUS_5V

COLUMN_NUMBER = 54

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 67

DESCRIPTION = "Analog +5 volt monitor."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = DIGITAL_PLUS_5V

COLUMN_NUMBER = 55

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 68

DESCRIPTION = "Digital +5 volt monitor."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_MINUS_5V

COLUMN_NUMBER = 56

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 69

DESCRIPTION = "GPC1-MG -5 volt monitor."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_MINUS_5V

COLUMN_NUMBER = 57

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 70

DESCRIPTION = "GPC2-AL -5 volt monitor."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_MINUS_5V

COLUMN_NUMBER = 58

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 71

DESCRIPTION = "GPC3-UN -5 volt monitor."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = SAX_MINUS_5V

COLUMN_NUMBER = 59

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 72

DESCRIPTION = "SAX -5 volt monitor."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = ANALOG_MINUS_5V

COLUMN_NUMBER = 60

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 73

DESCRIPTION = "Analog -5 volt monitor."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = TEC_I

COLUMN_NUMBER = 61

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 74

DESCRIPTION = "TEC current."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = MXU_TEMP

COLUMN_NUMBER = 62

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 75

DESCRIPTION = "MXU temperature."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = SOLAR_DETECTOR_TEMP

COLUMN_NUMBER = 63

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 76

DESCRIPTION = "Solar detector temperature."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = SAX_TEMP

COLUMN_NUMBER = 64

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 77

DESCRIPTION = "SAX temperature."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = SOLAR_DETECTOR_I

COLUMN_NUMBER = 65

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 78

DESCRIPTION = "Solar detector current."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_VOLTAGE_STEPPING

COLUMN_NUMBER = 66

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 79

DESCRIPTION = "Indicates whether the GPC1-MG detector's high

voltage state is seeking. See the MESSENGER XRS Software

Specification document for an explanation of the seeking state. =0

no, =1 yes."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_VOLTAGE

COLUMN_NUMBER = 67

BYTES = 2

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 80

DESCRIPTION = "GPC1-MG voltage measurement."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_VOLTAGE_STEPPING

COLUMN_NUMBER = 68

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 82

DESCRIPTION = "Indicates whether the GPC2-AL detector's high

voltage state is seeking. See the MESSENGER XRS Software

Specification document for an explanation of the seeking state. =0

no, =1 yes."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_VOLTAGE

COLUMN_NUMBER = 69

BYTES = 2

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 83

DESCRIPTION = "GPC2-AL voltage measurement."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_VOLTAGE_STEPPING

COLUMN_NUMBER = 70

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 85

DESCRIPTION = "Indicates whether the GPC3-UN detector's high

voltage state is seeking. See the MESSENGER XRS Software

Specification document for an explanation of the seeking state. =0

no, =1 yes."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_VOLTAGE

COLUMN_NUMBER = 71

BYTES = 2

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 86

DESCRIPTION = "GPC3-UN voltage measurement."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = BIAS_SUPPLY_VOLT_STEPPING

COLUMN_NUMBER = 72

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 88

DESCRIPTION = "Indicates whether the Bias detector's high voltage

state is seeking. See the MESSENGER XRS Software Specification

document for an explanation of the seeking state. =0 no, =1 yes."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = BIAS_VOLTAGE

COLUMN_NUMBER = 73

BYTES = 2

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 89

DESCRIPTION = "Bias voltage measurement."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_SUPPLY_TEMP

COLUMN_NUMBER = 74

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 91

DESCRIPTION = "GPC1-MG supply temperature measurement."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_SUPPLY_TEMP

COLUMN_NUMBER = 75

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 92

DESCRIPTION = "GPC2-AL supply temperature measurement."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_SUPPLY_TEMP

COLUMN_NUMBER = 76

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 93

DESCRIPTION = "GPC3-UN supply temperature measurement."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = BIAS_SUPPLY_TEMP

COLUMN_NUMBER = 77

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 94

DESCRIPTION = "Bias supply temperature measurement."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = ACTUAL_INTEGRATION_TIME

COLUMN_NUMBER = 78

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 95

DESCRIPTION = "Actual integration period in seconds."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = ACTUAL_REPORTING_TIME

COLUMN_NUMBER = 79

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 99

DESCRIPTION = "Actual reporting time in seconds."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_POWER_ANALOG

COLUMN_NUMBER = 80

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 103

DESCRIPTION = "GPC1-MG analog power setting. =0 disabled, =1

enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_POWER_HVPS

COLUMN_NUMBER = 81

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 104

DESCRIPTION = "GPC1-MG HVPS power setting, =0 disabled, =1

enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_VOLTAGE_SETTING

COLUMN_NUMBER = 82

BYTES = 2

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 105

DESCRIPTION = "GPC1-MG voltage setting."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_POWER_ANALOG

COLUMN_NUMBER = 83

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 107

DESCRIPTION = "GPC2-AL analog power setting, =0 disabled, =1

enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_POWER_HVPS

COLUMN_NUMBER = 84

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 108

DESCRIPTION = "GPC2-AL HVPS power setting, =0 disabled, =1

enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_VOLTAGE_SETTING

COLUMN_NUMBER = 85

BYTES = 2

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 109

DESCRIPTION = "GPC2-AL voltage setting."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_POWER_ANALOG

COLUMN_NUMBER = 86

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 111

DESCRIPTION = "GPC3-UN analog power setting."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_POWER_HVPS

COLUMN_NUMBER = 87

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 112

DESCRIPTION = "GPC3-UN HVPS power setting, =0 disabled, =1

enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_VOLTAGE_SETTING

COLUMN_NUMBER = 88

BYTES = 2

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 113

DESCRIPTION = "GPC3-UN voltage setting."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = PIN_POWER_ANALOG

COLUMN_NUMBER = 89

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 115

DESCRIPTION = "PIN analog power setting. =0 disabled, =1 enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = PIN_TEC_ENABLE

COLUMN_NUMBER = 90

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 116

DESCRIPTION = "PIN TEC enable, =0 disabled, =1 enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = PIN_TEC_MODE

COLUMN_NUMBER = 91

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 117

DESCRIPTION = "PIN TEC mode, =0 cool, =1 heat."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = PIN_POWER_BIAS

COLUMN_NUMBER = 92

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 118

DESCRIPTION = "PIN power bias =0 disabled, =1 enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = BIAS_VOLTAGE_SETTING

COLUMN_NUMBER = 93

BYTES = 2

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 119

DESCRIPTION = "Bias voltage setting."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_LOW_LEVEL_DISC

COLUMN_NUMBER = 94

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 121

DESCRIPTION = "GPC1-MG low level discriminator."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_RISE_TIME_DISC_1

COLUMN_NUMBER = 95

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 122

DESCRIPTION = "GPC1-MG rise time discriminator 1."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_RISE_TIME_DISC_2

COLUMN_NUMBER = 96

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 123

DESCRIPTION = "GPC1-MG rise time discriminator 2."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_VETO_DISC

COLUMN_NUMBER = 97

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 124

DESCRIPTION = "GPC1-MG veto discriminator."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_LOW_LEVEL_DISC

COLUMN_NUMBER = 98

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 125

DESCRIPTION = "GPC2-AL low level discriminator."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_RISE_TIME_DISC_1

COLUMN_NUMBER = 99

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 126

DESCRIPTION = "GPC2-AL rise time discriminator 1."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_RISE_TIME_DISC_2

COLUMN_NUMBER = 100

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 127

DESCRIPTION = "GPC2-AL rise time discriminator 2."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_VETO_DISC

COLUMN_NUMBER = 101

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 128

DESCRIPTION = "GPC2-AL veto discriminator."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_LOW_LEVEL_DISC

COLUMN_NUMBER = 102

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 129

DESCRIPTION = "GPC3-UN low level discriminator."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_RISE_TIME_DISC_1

COLUMN_NUMBER = 103

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 130

DESCRIPTION = "GPC3-UN rise time discriminator 1."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_RISE_TIME_DISC_2

COLUMN_NUMBER = 104

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 131

DESCRIPTION = "GPC3-UN rise time discriminator 2."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_VETO_DISC

COLUMN_NUMBER = 105

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 132

DESCRIPTION = "GPC3-UN veto discriminator."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = PIN_LOW_LEVEL_DISC

COLUMN_NUMBER = 106

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 133

DESCRIPTION = "PIN low level discriminator (energy threshold)."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = TEC_CURRENT_SETTING

COLUMN_NUMBER = 107

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 134

DESCRIPTION = "TEC current setting."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = SPARE_DAC_1

COLUMN_NUMBER = 108

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 135

DESCRIPTION = "Spare column (DAC 1)."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = SPARE_DAC_2

COLUMN_NUMBER = 109

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 136

DESCRIPTION = "Spare column (DAC 2)."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_RISE_PILEUP

COLUMN_NUMBER = 110

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 137

DESCRIPTION = "RISE PILEUP criterion to determine valid

event for GPC2_AL detector. =0 disabled, =1 enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_RISE_TIME

COLUMN_NUMBER = 111

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 138

DESCRIPTION = "RISE TIME criterion to determine valid

event for GPC2_AL detector. =0 disabled, =1 enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_PILEUP_ENABLE

COLUMN_NUMBER = 112

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 139

DESCRIPTION = "PILEUP_ENABLE criterion to determine valid

event for GPC2_AL detector. =0 disabled, =1 enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_VETO_ENABLE

COLUMN_NUMBER = 113

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 140

DESCRIPTION = "VETO_ENABLE criterion to determine valid

event for GPC2_AL detector. =0 disabled, =1 enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_ENABLE

COLUMN_NUMBER = 114

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 141

DESCRIPTION = "ENABLE criterion to determine valid

event for GPC2_AL detector. =0 disabled, =1 enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_RISE_PILEUP

COLUMN_NUMBER = 115

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 142

DESCRIPTION = "RISE PILEUP criterion to determine valid

event for GPC1_MG detector. =0 disabled, =1 enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_RISE_TIME

COLUMN_NUMBER = 116

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 143

DESCRIPTION = "RISE TIME criterion to determine valid

event for GPC1_MG detector. =0 disabled, =1 enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_PILEUP_ENABLE

COLUMN_NUMBER = 117

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 144

DESCRIPTION = "PILEUP ENABLE criterion to determine valid

event for GPC1_MG detector. =0 disabled, =1 enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_VETO_ENABLE

COLUMN_NUMBER = 118

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 145

DESCRIPTION = "VETO ENABLE criterion to determine valid

event for GPC1_MG detector. =0 disabled, =1 enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_ENABLE

COLUMN_NUMBER = 119

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 146

DESCRIPTION = "ENABLE criterion to determine valid

event for GPC1_MG detector. =0 disabled, =1 enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = DEBUG_COUNTERS

COLUMN_NUMBER = 120

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 147

DESCRIPTION = "Diagnostic for planetary sensor. =0 disabled, =1

enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = PIN_PILEUP_ENABLE

COLUMN_NUMBER = 121

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 148

DESCRIPTION = "PIN PILEUP criterion to determine valid

event for PIN detector. =0 disabled, =1 enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = PIN_ENABLE

COLUMN_NUMBER = 122

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 149

DESCRIPTION = "ENABLE criterion to determine valid

event for PIN detector. =0 disabled, =1 enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_RISE_PILEUP

COLUMN_NUMBER = 123

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 150

DESCRIPTION = "RISE PILEUP criterion to determine valid

event for GPC3_UN detector. =0 disabled, =1 enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_RISE_TIME

COLUMN_NUMBER = 124

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 151

DESCRIPTION = "RISE TIME criterion to determine valid

event for GPC3_UN detector. =0 disabled, =1 enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_PILEUP_ENABLE

COLUMN_NUMBER = 125

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 152

DESCRIPTION = "PILEUP ENABLE criterion to determine valid

event for GPC3_UN detector. =0 disabled, =1 enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_VETO_ENABLE

COLUMN_NUMBER = 126

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 153

DESCRIPTION = "VETO ENABLE criterion to determine valid

event for GPC3_UN detector. =0 disabled, =1 enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_ENABLE

COLUMN_NUMBER = 127

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 154

DESCRIPTION = "ENABLE criterion to determine valid

event for GPC3_UN detector. =0 disabled, =1 enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = SOLAR_MONITOR_RATE

COLUMN_NUMBER = 128

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 155

DESCRIPTION = "Solar monitor detector rate per integration

period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = SOLAR_MONITOR_PILEUP_RATE

COLUMN_NUMBER = 129

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 159

DESCRIPTION = "Solar monitor pileup rate per integration period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = SOLAR_MONITOR_VALID_RATE

COLUMN_NUMBER = 130

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 163

DESCRIPTION = "Solar monitor valid rate per integration period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = SOLAR_MONITOR_ANALYZED_RATE

COLUMN_NUMBER = 131

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 167

DESCRIPTION = "Solar monitor analyzed rate per integeration

period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = SOLAR_MONITOR_HIGH_E_RATE

COLUMN_NUMBER = 132

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 171

DESCRIPTION = "Solar monitor high energy rate per integration

period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = SOLAR_MONITOR_LOSS

COLUMN_NUMBER = 133

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 175

DESCRIPTION = "Solar monitor loss percentage."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_CENTER_ANODE_RATE

COLUMN_NUMBER = 134

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 176

DESCRIPTION = "GPC1-MG center anode rate per integration period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_VETO_ANODE_RATE

COLUMN_NUMBER = 135

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 180

DESCRIPTION = "GPC1-MG veto anode rate per integration period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_VETO_RATE

COLUMN_NUMBER = 136

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 184

DESCRIPTION = "GPC1-MG veto rate per integration period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_PILEUP_RATE

COLUMN_NUMBER = 137

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 188

DESCRIPTION = "GPC1-MG pileup rate per integration period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_RISE_PILEUP_RATE

COLUMN_NUMBER = 138

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 192

DESCRIPTION = "GPC1-MG rise pileup rate per integration period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_VALID_RATE

COLUMN_NUMBER = 139

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 196

DESCRIPTION = "GPC1-MG valid rate per integration period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_ANALYZED_EVENT_RATE

COLUMN_NUMBER = 140

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 200

DESCRIPTION = "GPC1-MG analyzed event rate per integration

period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_RISE_TIME_REJECT

COLUMN_NUMBER = 141

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 204

DESCRIPTION = "GPC1-MG rise time reject rate per integration

period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_HIGH_ENERGY_RATE

COLUMN_NUMBER = 142

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 208

DESCRIPTION = "GPC1-MG high energy rate per integration period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_SPARE_RATE_1

COLUMN_NUMBER = 143

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 212

DESCRIPTION = "Spare column for GPC1-MG rates per integration

period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_SPARE_RATE_2

COLUMN_NUMBER = 144

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 216

DESCRIPTION = "Spare column for GPC1-MG rates."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_LOSS_PERCENTAGE

COLUMN_NUMBER = 145

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 220

DESCRIPTION = "GPC1-MG loss percentage."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_CENTER_ANODE_RATE

COLUMN_NUMBER = 146

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 221

DESCRIPTION = "GPC2-AL center anode rate per integration period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_VETO_ANODE_RATE

COLUMN_NUMBER = 147

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 225

DESCRIPTION = "GPC2-AL veto anode rate per integration period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_VETO_RATE

COLUMN_NUMBER = 148

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 229

DESCRIPTION = "GPC2-AL veto rate per integration period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_PILEUP_RATE

COLUMN_NUMBER = 149

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 233

DESCRIPTION = "GPC2-AL pileup rate per integration period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_RISE_PILEUP_RATE

COLUMN_NUMBER = 150

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 237

DESCRIPTION = "GPC2-AL rise pileup rate per integration period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_VALID_RATE

COLUMN_NUMBER = 151

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 241

DESCRIPTION = "GPC2-AL valid rate per integration period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_ANALYZED_EVENT_RATE

COLUMN_NUMBER = 152

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 245

DESCRIPTION = "GPC2-AL analyzed event rate per integration

period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_RISE_TIME_REJECT

COLUMN_NUMBER = 153

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 249

DESCRIPTION = "GPC2-AL rise time reject rate per integration

period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_HIGH_ENERGY_RATE

COLUMN_NUMBER = 154

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 253

DESCRIPTION = "GPC2-AL high energy rate per integration period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_SPARE_RATE_1

COLUMN_NUMBER = 155

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 257

DESCRIPTION = "GPC2-AL spare rates column."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_SPARE_RATE_2

COLUMN_NUMBER = 156

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 261

DESCRIPTION = "GPC2-AL spare rates column."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_LOSS_PERCENTAGE

COLUMN_NUMBER = 157

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 265

DESCRIPTION = "GPC2-AL loss percentage."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_CENTER_ANODE_RATE

COLUMN_NUMBER = 158

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 266

DESCRIPTION = "GPC3-UN center anode rate per integration period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_VETO_ANODE_RATE

COLUMN_NUMBER = 159

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 270

DESCRIPTION = "GPC3-UN veto anode rate per integration period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_VETO_RATE

COLUMN_NUMBER = 160

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 274

DESCRIPTION = "GPC3-UN veto rate per integration period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_PILEUP_RATE

COLUMN_NUMBER = 161

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 278

DESCRIPTION = "GPC3-UN pileup rate per integration period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_RISE_PILEUP_RATE

COLUMN_NUMBER = 162

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 282

DESCRIPTION = "GPC3-UN rise pileup rate per integration period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_VALID_RATE

COLUMN_NUMBER = 163

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 286

DESCRIPTION = "GPC3-UN valid rate per integration period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_ANALYZED_EVENT_RATE

COLUMN_NUMBER = 164

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 290

DESCRIPTION = "GPC3-UN analyzed event rate per integration

period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_RISE_TIME_REJECT

COLUMN_NUMBER = 165

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 294

DESCRIPTION = "GPC3-UN rise time reject rate per integration

period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_HIGH_ENERGY_RATE

COLUMN_NUMBER = 166

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 298

DESCRIPTION = "GPC3-UN high energy rate per integration period."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_SPARE_RATE_1

COLUMN_NUMBER = 167

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 302

DESCRIPTION = "Spare column for GPC3-UN rates."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_SPARE_RATE_2

COLUMN_NUMBER = 168

BYTES = 4

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 306

DESCRIPTION = "Spare column for GPC3-UN rates."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_LOSS_PERCENTAGE

COLUMN_NUMBER = 169

BYTES = 1

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 310

DESCRIPTION = "GPC3-UN loss percentage."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = SOLAR_STABILITY

COLUMN_NUMBER = 170

BYTES = 20

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 311

ITEMS = 10

ITEM_BYTES = 2

DESCRIPTION = "A 10 element array of solar monitor detector rate

measurements. The integration period is divided into 10 equal

segments with an accumulated rate (per second) for each. Valid data

for this column is only obtained by the instrument if solar flare

handling is enabled at the start of the integration and reporting

period. Values are set to a default of 999 if solar flare handling

was not enabled."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = SOLAR_MONITOR_SPECT_SHIFT

COLUMN_NUMBER = 171

BYTES = 2

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 331

DESCRIPTION = "The divisor (bit shift) for the Solar Monitor

spectrum. When any channel in the solar monitor spectrum exceeds

65535, the spectrum is shifted to the right, throwing out the least

significant bits, keeping the 16 most significant bits."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = SOLAR_MON_SPECTRUM_23_253

COLUMN_NUMBER = 172

BYTES = 462

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 333

ITEMS = 231

ITEM_BYTES = 2

DESCRIPTION = "Solar monitor spectra channels (23-253)."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC1_MG_SPECTRUM_10_253

COLUMN_NUMBER = 173

BYTES = 488

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 795

ITEMS = 244

ITEM_BYTES = 2

DESCRIPTION = "GPC1-MG spectra channels (10-253)."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC2_AL_SPECTRUM_10_253

COLUMN_NUMBER = 174

BYTES = 488

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 1283

ITEMS = 244

ITEM_BYTES = 2

DESCRIPTION = "GPC2-AL spectra channels (10-253)."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = GPC3_UN_SPECTRUM_10_253

COLUMN_NUMBER = 175

BYTES = 488

DATA_TYPE = MSB_UNSIGNED_INTEGER

START_BYTE = 1771

ITEMS = 244

ITEM_BYTES = 2

DESCRIPTION = "GPC3-UN spectra channels (10-253)."

END_OBJECT = COLUMN

8.2 APPENDIX: XRS_CMDECHO.FMT File

The following is the full content of the XRS_CMDECHO.FMT file describing the ASCII fields.

OBJECT = COLUMN

NAME = MET

COLUMN_NUMBER = 1

BYTES = 12

DATA_TYPE = ASCII_INTEGER

START_BYTE = 1

DESCRIPTION = "Mission Elapsed Time in seconds."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = CMD_UTC_TIME

COLUMN_NUMBER = 2

BYTES = 19

DATA_TYPE = CHARACTER

START_BYTE = 15

DESCRIPTION = "UTC time in YYYY-MM-DDTHH:MM:SS format derived from the

MET using SPICE kernels."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = MACRO_FLAG

COLUMN_NUMBER = 3

BYTES = 3

DATA_TYPE = CHARACTER

START_BYTE = 37

DESCRIPTION = "Identifies the command echo as a single command (CMD) or

part of a command macro (MAC)."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = CMD_RESULT

COLUMN_NUMBER = 4

BYTES = 3

DATA_TYPE = ASCII_INTEGER

START_BYTE = 43

DESCRIPTION = "Indicates the level of success for the command.

The success level is command dependent and is described for each

separate command in the XRS Flight Software Document."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = CMD_OPCODE

COLUMN_NUMBER = 5

BYTES = 4

DATA_TYPE = CHARACTER

START_BYTE = 49

DESCRIPTION = "The command opcode expressed as a hexidecimal string."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = CMD_OPCODE_STRING

COLUMN_NUMBER = 6

BYTES = 40

DATA_TYPE = CHARACTER

START_BYTE = 57

DESCRIPTION = "The hex command translated into a string mnemonic.

A hex command without an associated string map is set to

UNDEFINED_CMD_STRING."

END_OBJECT = COLUMN

OBJECT = COLUMN

NAME = CMD_ARG_PARAMETERS

COLUMN_NUMBER = 7

BYTES = 22

DATA_TYPE = CHARACTER

START_BYTE = 101

DESCRIPTION = "The command echo packet returns up to the first 10

command arguments. Most commands contain less than 10. The

arguments are represented by a single hex string. The decoding of

the hex string is command dependent and described for each separate

command in the XRS Flight Software Document."

END_OBJECT = COLUMN

8.3 APPENDIX: SPICE Kernel Files Used in MESSENGER Data Products

The following SPICE kernel files will be used to compute the UTC time and any geometric quantities found in the PDS labels. Kernel files will be generated throughout the mission with a filenaming convention specified by the MESSENGER project.

*.bsp:

MESSENGER spacecraft ephemeris file. Also known as the Planetary Spacecraft Ephemeris Kernel (SPK) file.

*.bc:

MESSENGER spacecraft orientation file. Also known as the Attitude C-Kernel (CK) file.

*.tf:

MESSENGER reference frame file. Also known as the Frames Kernel. Contains the MESSENGER spacecraft, science instrument, and communications antennae frame definitions.

*.ti:

MESSENGER instrument kernel (I-kernel). Contains references to mounting alignment, operation modes, and timing as well as internal and field of view geometry for the XRS.

*.tsc:

MESSENGER spacecraft clock coefficients file. Also known as the Spacecraft Clock Kernel (SCLK) file.

*.tpc:

Planetary constants file. Also known as the Planetary Contants Kernel (PcK) file.

*.tls:

NAIF leapseconds kernel file. Used in conjunction with the SCLK kernel to convert between Universal Time Coordinated (UTC) and MESSENGER Mission Elapsed Time (MET). Also called the Leap Seconds Kernel (LSK) file.

8.4 APPENDIX: CODMAC/NASA Definition of Processing Levels

CODMAC/NASA Definition of processing levels for science data sets

CODMAC Level	Proc. Type	Data Processing Level Description
1	Raw Data	Telemetry data stream as received at the ground station, with science and engineering data embedded. Corresponds to NASA packet data.
2	Edited Data	Instrument science data (e.g. raw voltages, counts) at full resolutoin, time ordered, with duplicates and transmission errors removed. Referred to in the MESSENGER program as Experiment Data Records (EDRs). Corresponds to NASA Level 0 data.
3	Calibrated Data	Edited data that are still in units produced by instrument, but have transformed (e.g. calibrated, rearranged) in a reversible manner and packaged with needed ancillary and auxiliary data (e.g. radiances with calibration equations applied). Referred to in the MESSENGER Program as Calibrated Data Records (CDRs). In some cases these also qualify as derived data products (DDRs). Corresponds to NASA Level 1A.
4	Resampled data	Irreversibly transformed (e.g. resampled, remapped, calibrated) values of the instrument measurements (e.g. radiances, magnetic field strength). Referred to in the MESSENGER program as either derived data products (DDPs) or derived analysis products (DAPs). Corresponds to NASA Level 1B.
5	Derived Data	Derived results such as maps, reports, graphics, etc. Corresponds to NASA Levels 2 through 5
6	Ancillary Data	Non-Science data needed to generate calibrated or resampled data sets. Consists of instrument gains, offsets; pointing information for scan platforms, etc.
7	Corrective Data	Other science data needed to interpret space-borne data sets. May include ground based data observations such as soil type or ocean buoy measurements of wind drift.
8	User Description	Description of why the data were required, any peculiarities associated with the data sets., and enough documentation to allow secondary user to extract information from the data.

The above is based on the national research council committee on data management and computation (CODMAC) data levels.

8.5 APPENDIX: MESSENGER XRS Glossary and Acronym List

ACT Applied Coherent Technology Corporation

APL The Johns Hopkins university Applied Physics Laboratory

ASCII American Standard Code for Information Interchange

CCSDS Consultative Committee for Space Data Systems

CDR Calibrated Data Record

CK Camera Kernel (SPICE)

CoDMAC Committee on Data Management and Computation

Co-I Co-Investigator

DN Digital Number, the raw telemetry count

DPU Data Processing Unit

DSN Deep Space Network

EDR Experiment Data Records

EPPS Energetic Particle and Plasma Spectrometer

ET Ephemeris Time

FIPS Fast Imaging Plasma Spectrometer

FOV Field-of-View

FTP File Transfer protocol

GC Geochemistry Group

GP Geophysics Group

GPC Gas Proportional Counter

GRNS Gamma-ray and Neutron Spectrometer

GSFC Goddard Space Flight Center

I&T Integration and Test

I2C Inter-Integrated Circuit

IEM Integrated Electronic Module

LSK Leapseconds Kernel (SPICE)

LVPS Low Voltage Power Supply

MAG Magnetometer

MASCS Mercury Atmospheric and Surface Composition Spectrometer

MDIS Mercury Dual Imaging System

MESSENGER Messenger, Surface, Space ENvironment, Geochemistry, and Ranging

MET Mission Elapsed Time

MXU Mercury X-ray Unit

NAIF Navigation and Ancillary Information Facility

NASA National Aeronautics and Space Administration

PCK Planetary Constant Kernel (SPICE)

PDS Planetary Data System

PIN Positive-Intrinsic-Negative silicon diode

SAX Solar Assembly for X-rays

SCLK Space Clock Kernel (SPICE)

SPICE Spacecraft, Planet, Instrument, C-matrix Events

SPK Spacecraft and Planets Kernel (SPICE)

TEC Thermal Electric Cooler

UTC Coordinated Universal Time

XRS X-Ray Spectrometer

8.6 APPENDIX: XRS Engineering Parameter Conversion Equations

The voltage, angle, temperature values in the XRS binary table are the raw telemetry counts extracted from the instrument science packet. To convert them into engineering values one must use the following conversion equation, unless otherwise noted in the following table:

C0+C1*n+C2*n²+C3*n³

Where n is the raw telemetry count in the EDR table record. C0, C1, C2, C3 are the coefficients. Values for the coefficients are presented for the following table columns:

Column Name in XRS Binary Table	EDR Binary Table Column Number	C0	C1	C2	C3	Units
SC_RANGE	3	0	30	0	0	Meters
SC_ANGLE	4	0	0.25	0	0	Degrees
LVPS_PLUS_5V	33	0	0.07935	0	0	Volts
LVPS_MINUS_5V	34	0	-0.07935	0	0	Volts
LVPS_PLUS_12V	35	0	0.07935	0	0	Volts
LVPS_MINUS_12V	36	0	-0.07935	0	0	Volts
LVPS_PLUS_5_I	42	0	7.808	0	0	mA
LVPS_MINUS_5_I	43	0	7.808	0	0	mA
LVPS_PLUS_12_I	44	0	7.808	0	0	mA
LVPS_MINUS_12_I	45	0	7.808	0	0	mA
LVPS_TEMP	46	-39.37	0.4227	-4.49E-05	5.08E-06	Deg C
LVPS_PRIMARY_I	47	0	7.808	0	0	mA
LVPS_SWITCHED_PRIMARY_I	48	0	7.808	0	0	mA
GPC1_MG_PLUS_5V	49	0	0.0421	0	0	Volts
GPC2_AL_PLUS_5V	50	0	0.0421	0	0	Volts
GPC3_UN_PLUS_5V	51	0	0.0421	0	0	Volts
SAX_PLUS_5V	52	0	0.0421	0	0	Volts
ANALOG_PLUS_5V	53	0	0.0421	0	0	Volts
DIGITAL_PLUS_5V	54	0	0.0421	0	0	Volts
GPC1_MG_MINUS_5V	55	See below
GPC2_AL_MINUS_5V	56	See below
GPC3_UN_MINUS_5V	57	See below
SAX_MINUS_5V	58	See below
ANALOG_MINUS_5V	59	-12.1	0.05732	0	0	Volts
TEC_I	60	0	2.34	0	0	mA
MXU_TEMP	61	See below
SOLAR_DETECTOR_TEMP	62	See below
SAX_TEMP	63	-273	1.47	0	0	Deg C
SOLAR_DETECTOR_I	64	-667	4.017	0	0	pA
GPC1_MG_VOLTAGE	66	0	0.507	0	0	Volts
GPC2_AL_VOLTAGE	68	0	0.507	0	0	Volts
GPC3_UN_VOLTAGE	70	0	0.507	0	0	Volts
BIAS_VOLTAGE	72	0	0.507	0	0	Volts
GPC1_MG_SUPPLY_TEMP	73	-99.4	1.028	0	0	Deg C
GPC2_AL_SUPPLY_TEMP	74	-101.4	1.028	0	0	Deg C
GPC3_UN_SUPPLY_TEMP	75	-100.4	1.028	0	0	Deg C
BIAS_SUPPLY_TEMP	76	-98.3	1.028	0	0	Deg C


		Conversion Equation¹
GPC1_MG_MINUS_5V	55	0.02559M5-0.068202P5				Volts
GPC2_AL_MINUS_5V	56	0.02559M5-0.068202P5				Volts
GPC3_UN_MINUS_5V	57	0.02559M5-0.068202P5				Volts
SAX_MINUS_5V	58	0.02559M5-0.068202P5				Volts
¹M5 is the raw value for this parameter. P5 is the raw value for the corresponding PLUS_5V parameter.

		Conversion Equation²
MXU_TEMP	61	-26.226*ln(a+1)+129.14				Deg C
SOLAR_DETECTOR_TEMP (Hi)	62	4.57782E-09a⁵ - 3.16578E-06a⁴ + 8.58411E-04*a³				Deg C
		- 1.11961E-01a² + 7.16858E+00a - 1.23365E+2
SOLAR_DETECTOR_TEMP (Lo)	62	2.06686[ln(a+1)]² - 38.94592ln(a+1) +107.39573				Deg C
²a is the raw value for these parameters. Hi is for anneal only. Lo is normal operations. Hi or Lo is determined by the PIN_TEC_ENABLE and PIN_TEC_MODE columns in the EDR. If either=0, use Lo. If both=1 use Hi.

Note that GPC1_MG_MINUS_5V, GPC2_AL_MINUS_5V, GPC3_UN_MINUS_5V, MXU_TEMP, SOLAR_DETECTOR_TEMP have their own conversion equations and do not use the C0-C3 coefficients.

[1] See instrument host catalog file in XRS EDR volume catalog directory for more information on MESSENGER spacecraft clock reset.

Version Number	Date	Changes
2I	4/24/2008	· Start of revision history: version included in MESSENGER PDS Release 4.
3	12/10/2009	· Added documentation for XRS Command Echo EDR. Command Echo EDRs contain a daily history of command echoes produced by the instrument.
3.1	12/11/2009	· Minor editorial changes, mostly for typos, by Richard Starr.
3.2	12/29/2009	· Minor edits to sec. 6.5.1 to include missing REF.CAT, PERSON.CAT, MD5.TAB, XRSINDEX.TAB and XRS_CMDECHO.FMT files. · Sec. 5.3.4: Replaced cmd echo file label example which had incorrect INTERCHANGE_FORMAT with a new correct one from the M3 Flyby.
3.3	01/07/2010	· Added N/A values for SC_RANGE and SC_ANGLE
3.4	06/16/2011	· Added Document Review information
3.4	06/16/2011	· Added info to Section 3 headers and footers
3.4	06/16/2011	· Changed “periherm” to “apoherm” in orbit start time description
3.4	08/25/2011	· Removed references to XRSINDEX.TAB/LBL
3.5	05/25/2012	· Change document title from MESSENGER Data Management and Science Analysis Plan to MESSENGER Data Management and Archiving Plan. Update references. · Reference MESSENGER Data Management and Archiving Plan for release schedule and remove release schedule, table B-1, from this document.
3.6	03/10/2014	· Corrected sec. 8.6: APPENDIX: XRS Engineering Parameter Conversion Equations footnote.
3.7	07/01/2015	· Change “Experimental Data Record” to “Experiment Data Record” in text. · Note use of clock partitions in time tags in product labels following January 8, 2013 S/C clock reset (Section 5.4.2).