MESSENGER GRS Derived Data

Gamma Ray Spectrometer (GRS) Derived product types

Instrument: MESSENGER Gamma Ray Spectrometer

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

MESSENGER PDS3 to PDS4 Migration Status: Complete

For more information about GRS derived 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 derived product collection has a series of maps derived from the GRS instrument for the northern hemisphere of Mercury. These were created from calibrated gamma ray spectra, represent spatially resolved measurements, and have been highly processed to remove variability originating from detector altitude and viewing geometry. The measurements were also corrected for dead time. Code refers to the product type abbreviation used in the file name.

Code	Product Type	Description	Storage Format
DAP	Map	The maps are either gamma ray count rates or derived elemental abundances.	Image Array and JPEG2000

GRS DAP products have the following file names:

grs_zzz_y_www_uuu.xxx

where:

zzz = Product Type (Code)

y = Element name in periodic table:

k = Potassium

si = Silicon

o = Oxygen

www = Map type:

abd = abundance

gcr = gamma-ray count rate

uuu = Map contents:

map = data

error = error

xxx = File extension:

jp2 = JPEG-2000

img = Image File