MESSENGER GRS Raw Data

Gamma Ray Spectrometer (GRS) Raw product types

Instrument: MESSENGER Gamma Ray Spectrometer

PDS4 Bundle (GRS Raw Data): urn:nasa:pds:mess_grs_rawDOI: 10.17189/1518577

MESSENGER PDS3 to PDS4 Migration Status: Complete

For more information about GRS raw products, see the Product SIS.

Note: The product SIS was created for PDS3, but it is still applicable to the data after the PDS4 migration.

The MESSENGER GRS raw product collection consists of uncalibrated observations from the GRS instrument. There are ten standard product types associated with the GRS sensor. Six product types contain spectra from either the high-purity germanium or scintillator detector. The remaining raw product types pertain to the operation of the GRS instrument, including a time-tagged list of commands executed. A single raw product typically contains data collected over one Earth day. A description of each product type is given in the table below. Code refers to the product type abbreviation used in the file name.

Code	Product Type	Description	Storage Format
ADC	FPGA ADC Diagnostic Information	This product type contains diagnostic information about the state of the instrument, with parameters associated with the Analog-to-Digital Converter (ADC) processing in the field-programmable gate array (FPGA).	Binary Table
ANC	Anti-Coincident Spectra	This data type contains high-purity germanium (HPGe) Anti-Coincident (AC) spectra collected by the MESSENGER Gamma Ray Spectrometer (GRS).	Binary Table
CMD	Command	The GRS Command product contains the set of commands executed by the GRS instrument.	ASCII Table
MID	Microphonics	The Microphonics product contains time series data of fluctuations generated electronically due to cryocooler vibrations. These data help determine if the cooler is developing vibration issues. The cryocooler failed on June 15, 2012.	Binary Table
RAW	HPGe Spectra	This data type contains raw spectra collected from the high-purity germanium (HPGe) detector.	Binary Table
SCR	Anti-Coincidence Shield	This data type contains high-resolution count rate data of events registered by the GRS Anti-Coincidence shield in 10 ms increments.	Binary Table
SHI	Shield Spectra	This product type contains raw spectra collected from the GRS shield detector prior to September 17, 2010.	Binary Table
SHI2	Shield Spectra 2	The GRS flight software was changed on September 17, 2010 to detect fast neutrons in the shield sensor.The shield-2 products are formatted to provide data on thermal and fast neutrons.	Binary Table
STA	Telemetry Status	These data files monitor engineering parameters, such as voltages, currents, temperatures, and modes in raw units.	ASCII Table
SWC	Software Telemetry	This data type contains software rate counter telemetry information of events measured by GRS.	ASCII Table

GRS Raw products have the following file names:

grs_zzzyyyydddwww.dat

where:

zzz = Product Type (Code)

yyyy = 4-digit year corresponding to the start time of the first record in the Raw data file

ddd = 3-digit day of year corresponding to the start time of the first record in the Raw data file

www = reserved 3-character string to use during the course of the mission as necessary to identify “special” data products; nominal data products will be identified with “ZZZ”