MESSENGER GRS Calibrated Data

Gamma Ray Spectrometer (GRS) Calibrated product types

Instrument: MESSENGER Gamma Ray Spectrometer

PDS4 Bundle (GRS Calibrated and Derived Data): urn:nasa:pds:mess_grs_derived DOI: 10.17189/1518584

MESSENGER PDS3 to PDS4 Migration Status: Complete

For more information about GRS calibrated 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 calibrated product collection consists of GRS data that have been calibrated for instrument and geometrical effects. There are eight product types in this collection that include spectra in addition to engineering and shield count rate data. Spectral products contain spacecraft navigation and attitude data derived from SPICE files, as well as selected relevant engineering data. A single 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, where relevant.

Code

Product Type

Description

Storage Format

CAC

Anti-Coincidence Spectra

This product type contains Anti-Coincident (AC) spectra collected from the high-purity germanium (HPGe) detector plus spatial and temporal information and relevant engineering, counter, and pulser data from the time the spectra was taken. Spectra have been corrected to a common energy scale.

Binary Table

CRA

Ge Raw Spectra

This product type contains spectra collected from the high-purity Germanium (HPGe) detector plus spatial and temporal information and relevant engineering, counter and pulser data from the time the spectra was taken. Spectra have been corrected to a common energy scale.

Binary Table

CS2

Shield Spectra 2

This product type contains spectra observed in the GRS shield and associated timing, spatial, and engineering data. These products were generated after September 17, 2010 due to a flight software update.

Binary Table

CS3

Shield Spectra 3

This product type contains spectra observed in the GRS shield. These products have timing, spatial and engineering readings taken at the mid-point of the spectral collection period associated with it. These products were generated after March 17, 2013 due to a flight software update.

ASCII Table

CSC

Shield Count Rate

The GRS shield count rate product contains time series measurements of the total count rate measured by the GRS anti-coincidence shield, and are due to incident particles (primarily electrons, but also gamma rays, protons, and neutrons). These products were generated after March 17, 2013 due to a February 25, 2013 flight software upload.

ASCII Table

CSH

Shield Spectra

This product type contains spectra observed in the GRS shield with associated timing, spatial, and engineering data. These products were generated prior to September 17, 2010.

Binary Table

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Engineering

The engineering products contain selected data from the GRS raw status files converted to calibrated physical units.

Binary Table

RSS

Spectral Sum

This product type contains spectra summed from the Ge Raw and the Anti-Coincident Spectra acquired with limited geometric conditions plus spatial and temporal information and relevant data from the time the spectra were taken.

Binary Table

GRS Calibrated products have the following file names:

grs_zzzyyyydddwww.xxx

where:

zzz = Product Type (Code)

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

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

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”

xxx = File extension:

dat = Binary table file

tab = ASCII table file

GRS Engineering Calibrated products have the following file names:

grs_zzzyyyydddwww.dat

where:

zzz = Engineering data code in the form of exx where xx is the "CDR Index" listed in Appendix 8.4 of the SIS.

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

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

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”