ChemCam data sets

Data Set Overview

This data set consists of all the uncalibrated data collected by the laser-induced breakdown spectroscopy (LIBS) spectrometers. This data will be used to quantitatively determine the chemical composition of rocks and regolith in order to characterize the materials in the vicinity of the rover.

Parameters

LIBS Spectra: Data files of Full pixel resolution from all three spectrometers, for each laser fired.

Processing

This data set uses the Committee On Data Management And Computation (CODMAC) data level numbering system. The EDRs are to be reconstructed from 'Level 1' or 'Raw Data', which are the telemetry packets within the project specific Standard Formatted Data Unit (SFDU) record.

ChemCam EDRs were generated by the MIPL (Multimission Image Processing Laboratory) at JPL under the Operation Products Generation Subsystem. The EDRs are raw uncalibrated data reconstructed from telemetry data products and formatted according to the Camera EDR/RDR Software Interface Specification. Meta-data acquired from the telemetry data headers and a meta-data database were used to propagate the PDS label.

RDRs will be produced in succession by the ChemCam Team and formatted according to this SIS, the RDR data product will be placed into FEI for distribution.

Data

The data are stored in multiple data files and have been organized by data products.

For LIBS the data product consist of the following:

• Ancillary data which includes SCLK, temperatures and command parameters and arguments.
• SOH Data Before and after the spectra data collect.
• LASER Data if the laser was fired.
• Auto Focus data if the Auto focus was used.
• Spectra Science Data.
• Command Reply for all DPO's

An attached PDL Label describes the content of the data file and format of the data can be found in referenced .FMT files.

Ancillary Data

Most of the ancillary data needed can be found in the data it self or in the label portion of the EDR. There is ancillary information included in the data of the data product.

Software

ChemCam downlink processing software used by the science and engineering team during operations is focused on rapid reduction, calibration, and visualization of spectral data in order to make rocks and soil around the rover, and to provide timely input for operational decisions concerning further analysis by ChemCam, SAM, APXS and CheMin.

Media/Format

The data set will be delivered and made available to the public through the Planetary Data System web sites.

Confidence Level Overview

The data presented in the LIBS EDR is intended to be the least processed, most primitive data set released for ChemCam. Data presented here are an accurate representation of LIBS data as received from the rover.

Review

The LIBS EDRs are reviewed internally by the ChemCam team prior to release to the PDS. PDS also performed an external peer review of the LIBS EDRs.

Data Coverage and Quality

Data reported are the minimally processed data received from the orbiter during nominal LIBS operations. All data received is reformatted into one of the EDR data types. Data are by definition of good quality, as damaged telemetry packets are sequestered upon receipt from the spacecraft. We do not expect to receive many (if any) damaged data packets.

Limitations

The major limitation of this data set is that this is level 0, minimally processed data.

Data Set Overview

This data set consists of all the uncalibrated data collected by the Remote Micro-Imager (RMI) camera. The ChemCam remote micro-imager (RMI) provides high resolution images primarily to give the morphological context for the LIBS analysis points, though it can also be used for imaging other features on Mars. It consists of a 1024 x 1024 pixel camera with a field of view of ~20 mrad. Its resolution is approximately 50 micro-radians. The RMI images a broad spectral band by picking off about 10% of the light from the ChemCam telescope. Having a narrow depth of focus, it uses an autofocus algorithm to acquire targets with in ~20 m, and can be focused manually to infinity. Images can be compressed without loss or with a lossy algorithm, and can be downlinked as thumbnails or subframes.

Parameters

RMI Imaging: The imager software inherited from Rosetta includes autoexposure algorithms, with typically four different exposures made, and the best image is kept. For a typical rock analysis scenario a full 1024x1024 pixel image is taken prior and subsequent to LIBS analysis to identify the analysis spot.

While LIBS and RMI will be used frequently together, there will be numerous times when RMI will be used separately, such as to provide close-up images to support arm-mounted experiments, or provide images of very distant objects.

Processing

This data set uses the Committee On Data Management And Computation (CODMAC) data level numbering system. The EDRs are to be reconstructed from 'Level 1' or 'Raw Data', which are the telemetry packets within the project specific Standard Formatted Data Unit (SFDU) record.

ChemCam EDRs were generated by the MIPL (Multimission Image Processing Laboratory) at JPL under the Operation Products Generation Subsystem. The EDRs are raw uncalibrated data reconstructed from telemetry data products and formatted according to the Camera EDR/RDR Software Interface Specification. Meta-data acquired from the telemetry data headers and a meta-data database were used to propagate the PDS label.

RDRs are produced in succession by MIPL at JPL with the guidance and the software of the ChemCam Team and formatted according to this SIS, the RDR data product will be placed into FEI for distribution.

Data

The data are stored in multiple data files and have been organized by data products. For RMI the data product consists of the following: Ancillary Data which includes SCLK, temperatures and command parameters and arguments. SOH Data Before and after the image. Auto Focus data if the Autofocus was used. Image Science Data As well as Command Reply data for each DPO.

An attached PDL Label describes the content of the data file and format of the data can be found in referenced .FMT files.

Ancillary Data

Most of the ancillary data needed can be found in the data it self or in the label portion of the EDR. Also included will be an Ancillary DPO.

Software

ChemCam downlink processing software used by the science and engineering team during operations is focused on rapid reduction, calibration, and visualization of images in order to make rocks and soil around the rover, and to provide timely input for operational decisions concerning further analysis by ChemCam, SAM, APXS and CheMin.

Media/Format

The data set will be delivered and made available to the public through the Planetary Data System web sites.

Confidence Level Overview

The data presented in the RMI EDR is intended to be the least processed, most primitive data set released for ChemCam. Data presented here are an accurate representation of RMI data as received from the rover.

Review

The RMI EDRs are reviewed internally by the ChemCam team prior to release to the PDS. PDS also performed an external peer review of the RMI EDRs.

Data Coverage and Quality

Data reported are the minimally processed data received from the orbiter during nominal RMI operations. All data received is reformatted into one of the EDR data types. Data are by definition of good quality, as damaged telemetry packets are sequestered upon receipt from the spacecraft. We do not expect to receive many (if any) damaged data packets.

Limitations

The major limitation of this data set is that this is level 0, minimally processed data.

Data Set Overview

The ChemCam SOH data product consists of various state of health parameters including the DPU voltages and temperatures, Mast Unit (MU) current and temperatures, as well as status of various data parameters.

Processing

This data set uses the Committee On Data Management And Computation (CODMAC) data level numbering system. The EDRs are to be reconstructed from 'Level 1' or 'Raw Data', which are the telemetry packets within the project specific Standard Formatted Data Unit (SFDU) record.

ChemCam EDRs were generated by the MIPL (Multimission Image Processing Laboratory) at JPL under the Operation Products Generation Subsystem. The EDRs are raw uncalibrated data reconstructed from telemetry data products and formatted according to the Camera EDR/RDR Software Interface Specification. Meta-data acquired from the telemetry data headers and a meta-data database were used to propagate the PDS label.

RDRs will be produced in succession by the ChemCam Team and formatted according to this SIS, the RDR data product will be placed into FEI for distribution.

Data

The data are stored in multiple data files and have been organized by data products. For SOH the data product consist of the following: Ancillary Data which includes SCLK, temperatures and command parameters and arguments. SOH science Data.

An attached PDL Label describes the content of the data file and format of the data can be found in referenced .FMT files.

Ancillary Data

Most of the ancillary data needed can be found in the data it self or in the label portion of the EDR.

Software

ChemCam downlink processing software used by the science and engineering team during operations is focused on rapid reduction, calibration, and visualization of State of Health data in order to make assessments on Health of ChemCam.

Media/Format

The data set will be delivered and made available to the public through the Planetary Data System web sites.

Confidence Level Overview

The data presented in the SOH EDR is intended to be the least processed, most primitive data set released for ChemCam. Data presented here are an accurate representation of ChemCam SOH data as received from the rover.

Review

The ChemCam SOH EDRs are reviewed internally by the ChemCam team prior to release to the PDS. PDS also performed an external peer review of the ChemCam EDRs.

Data Coverage and Quality

Data reported are the minimally processed data received from the orbiter during nominal LIBS operations. All data received is reformatted into one of the EDR data types. Data are by definition of good quality, as damaged telemetry packets are sequestered upon receipt from the spacecraft. We do not expect to receive many (if any) damaged data packets.

Limitations

The major limitation of this data set is that this is level 0, minimally processed data.

Data Set Overview

ChemCam LIBS RDR data set contains calibrated spectra and higher level products derived from raw data collected by the ChemCam Laser Induced Breakdown Spectrometer on the Mars Science Laboratory rover. Standard derived products include summed calibrated spectra (RDR), CCS (Intermediate Clean Calibrated Spectra) and MOC (Multivariate Prediction of Oxide Composition) tables.

The MOC results are based on the average of the CCS. Shot to shot MOC results can be requested from the ChemCam team.

Processing

The Committee On Data Management and Computation (CODMAC) data level numbering system is used to describe the processing level of the EDR data product. ChemCam LIBS data products are considered CODMAC Level 4/5(equivalent to NASA level 1B/level 2) products.

ChemCam processed data products are generated by the ChemCam team. They consist of an RDR (reduced data record) spectrum produced by averaging spectra from all but the first five laser pulses at each observation point, subtracting a background, removing high-frequency noise, and removing the white-light continuum; a clean calibrated spectrum (CCS) produced by correcting for the instrument optical response in addition to the RDR processing mentioned above; and mean oxide compositions (MOC) for the major elements SiO2, TiO2, Al2O3, FeOT, MgO, CaO, Na2O, and K2O determined by using a partial least squares (PLS) regression algorithm trained on a LIBS spectral library. Data processing details are given in Wiens et al., 2013. In place of the PLS2 algorithm described in Wiens et al., 2013, the ChemCam team now uses a PLS1 algorithm. Whereas PLS2 regresses against all elements simultaneously, PLS1 regresses each element separately. Using PLS1 has several advantages due to the fact that elements can be treated separately. The number of components used in determining the oxide wt. % abundances can be optimized individually for each element. This is helpful, as the major elements manifest themselves very differently in the spectra, with some elements like Na and K having very few major emission lines and other elements like Fe having hundreds of emission lines. Optimizing the number of components separately for each element thus makes sense. Secondly, the list of standards used in the training set can be changed for different elements. This is important because a few elements, especially among minor or trace elements, do not have certified values for all of the standards. PLS1 also allows different normalization treatments for the different elements. We have found that normalizing each spectrometer output separately improves the results in a few cases over normalizing to the combined output of all three spectrometers together.

The number of components and normalization (1 = normalization to total emission sum; 3 = separate normalization of total emission for each spectrometer) is given below, as well as statistics on the compositional ranges and distributions for the training set, and the root mean square error (RMSE) are given in the table below:

	SiO2	TiO2	Al2O3	FeOT	MgO	CaO	Na2O	K2O	Total
TRAINING SET MIN.	0.2	0	0	0	0	0.1	0	0
TRAINING SET 1ST QUARTILE	40.8	0.27	5	2.7	0.8	2.5	0.3	0.3
TRAINING SET MEDIAN	48.6	0.68	13.1	6	2.2	7.1	2.4	0.8
TRAINING SET 3RD QUARTILE	59.3	1.47	16.1	12.1	6.4	12.8	3.4	1.8
TRAINING SET MAX.	75.4	5.9	38.8	36.2	49.2	54.9	5.9	6.4
NORMALIZATION	3	1	1	1	1	3	1	3
NUMBER OF COMPONENTS	8	10	4	7	8	8	10	4
RMSEP	7.1	0.55	3.7	4	3	3	0.7	0.9	10

Data

Each ChemCam LIBS RDR data file is a table. Columns are variable length and are delimited with commas. Each row is terminated with a carriage return and line feed character.

Confidence Level Overview

CCS: slight issues with continuum removal. See Wiens et al., 2013.

Review

This ChemCam archive has undergone a standard Planetary Data System peer review.

Data Set Overview

This data set consists of images of the geologic context of each target sampled with the ChemCam Laser-Induced Breakdown Spectrometers (LIBS). The Remote Micro-Imager (RMI) image field-of-view of about 20 mrad for 1024 pixels is adequate to localize the laser pits by comparing the image taken before and after the laser activities. The depth-of-field varies from 4 to 1000 mm as function of the target distance (respectively between 1 and 20 m). Most of the time the exposure time is set by an autoexposure algorithm; It is generally around 20 msec.

Parameters

The RMI camera head made of a Thomson-CSF TH7888A detector (1024 x 1024 pixels, 10 bits) and produces monochromatic images. The photometric response is very close to linear up to 670 DN (with a gain setting of 13), while the saturation level is at 840 DN.

Processing

The RDRs have been processed to remove dark current, smearing and flat field effects, as well as ghost images from the raw EDRs. The image is also stretched before being saved as TIF file. This produces Partially Radiometrically Corrected (PRC) images.

These images are generated by JPL's Multimission Image Processing Laboratory (MIPL) under the OPGS subsystem, using a code developed by Olivier Gasnault at Institut de Recherche en Astrophysique et Planetologie (IRAP).

Data

Each RMI RDR, also known as Partially Radiometrically Corrected (PRC), is made of a pair of file: a standard TIF file and a detached label text files (LBL).

Ancillary Data

The ancillary data in the RDR detached label file are the same than those in the EDR file that was used as input.

Coordinate System

The coordinates available in the RDR detached label file are the same than those in the EDR file that was used as input.

Confidence Level Overview

The RMI RDR images are not fully corrected radiometrically and are only meant to be used for qualitative interpretation of the context at small scales.

Review

This ChemCam archive has undergone a standard Planetary Data System peer review.

Data Coverage and Quality

Similar to ChemCam LIBS coverage.

Limitations

See confidence note above.