PDS_VERSION_ID      = PDS3
RECORD_TYPE         = STREAM

OBJECT              = TEXT
  PUBLICATION_DATE  = 2019-03-11
  NOTE              = "Description of contents of EXTRAS directory"
END_OBJECT          = TEXT
END

MSL APXS RDR EXTRAS Directory

The EXTRAS directory in this APXS archive contains the following 
additional material which may be of interest to the user.

MSL_APXS_ACTIVITIES_SOLnnnn_mmmm.CSV - These are tables that lists APXS EDR 
product IDs, associated target information, and comments. The "nnnn_mmmm"
in the file name represents a range of sol numbers. The tables are comma-
separated-value ASCII text files which may be viewed in a text editor or 
loaded into spreadsheet software such as Excel.

MSL_APXS_CONCENTRATIONS_MNO_RECALIB.CSV - This table describes 
an issue with the internal HV gradually starting around sol 1000. It 
impacted only the MnO concentration values. A parameter upload on sol 1267 
fixed this issue. The previous data were refitted with an adjusted fit model. 
All concentrations until sol 1293 are contained in this file with adjusted 
MnO values before sol 1267. 

MSL_APXS_SOL_0_359_VER2_RG.CSV and MSL_APXS_CONCENTRATIONS_nnnn_mmmm.CSV - 
This table lists APXS extracted concentrations. The table is a 
comma-separated-value ASCII text file which may be viewed in a text editor 
or loaded into spreadsheet software such as Excel.

VER1 represented the results used for LPSC 2013 abstracts and used in ver1 
PDS RDRs. It assumed an unchanged APXS calibration target, however, Mg and Fe 
deposits from the landing on top of the rock slab made a recalibration 
necessary.

VER2 represents the strict cross calibration from the lab calibration to 
Mars, taking into account 8 mbar CO2, lab and Mars sources and APXS 
calibation target contamination. VER 2 is used in the Sept 2013 and Dec 
2013 Science papers.

The table represents all samples measured with the MSL APXS. Some samples 
were measured only very short ( ~ 10 minutes), some at very unfavorable 
temperatures with very bad FWHM and some at very large standoff. The 
expected outcome of these spectra was to check for major elements only. 
The error bars given to all elements tries to capture these very unusual 
circumstances, but might be not fully correct for minor and trace elements.
Therefore the user is highly encouraged to check the spectra, the lifetime, 
the FWHM and the norm to verify the quality of the data before 
overinterpreting minor and trace elements in these spectra.

Good quality spectra are typically represented with lifetimes of at least 1 
hour, a standoff less than 2 cm ( ~ 25 % norm) and FWHM below ~ 175 eV.

A verification of distance dependent corrections on Mars, mainly impacting 
P, K and Ti is still pending.