Pancam data sets

Data Set Overview

This data set contains raw Pancam science data. If 12 to 8 bit scaling was commanded, these images HAVE been transformed back to 12 bits. Therefore, these images can be used for quantitative studies of the surface color and mineralogic properties, to constrain aerosol physical and radiative properties, and to asses the morphology, topography, and geologic context of each rover site.

Processing

This documentation uses the Committee on Data Management and Computation (CODMAC) data level numbering system. The MER Camera Payload EDRs referred to in this document are considered Level 2 or Edited Data (equivalent to NASA Level 0). 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. They are to be assembled into complete images, but will not be radiometrically or geometrically corrected.

EDR data products will be generated by MIPL using the telemetry processing software mertelemproc at JPL. The EDRs produced will be raw uncalibrated data reconstructed from telemetry packet SFDUs and formatted according to this SIS. Meta-data acquired from the telemetry data headers and a meta-data database will be used to populate the PDS label. Missing packets will be identified and reported for retransmission to the ground as partial datasets. Prior to retransmission, the missing EDR data will be filled with zeros. The EDR data will be reprocessed only after all partial datasets are retransmitted and received on the ground. In these cases, the original EDR version will be overwritten.

Data

As the fundamental science image data archive product, the Science EDR will be generated by the Athena Pancam Science and Microscopic Imager Science Teams under SOAS at JPL to recover the original 12-bit raw measurement obtained by the respective science camera to within the uncertainty of the noise in the original measured value. The size of a Science EDR data product is approximately 2 MB. The total estimated volume of Science EDRs over the course of the nominal 90-day MER mission is less than that of the Operations EDRs, and depends on the definition of the Science EDR archive set.

The data packaged in the camera data files will be decoded, decompressed camera image data in single frame form as an Experiment Data Record (EDR). The Full Frame form of a standard image data file has the maximum dimensions of 1024 lines by 1024 samples.

1. Full Frame EDR Full Frame EDRs are stored as 16-bit signed integers. If 12-to-8 bit scaling is performed, then pixels are stored in 16-bit format and only the last 8 bits of the 16-bit integer are used.
2. Thumbnail EDR Thumbnail EDRs are stored as 16-bit signed integers or 8-bit unsigned integers. If 12-to-8 bit scaling is performed, then pixels are stored in 16-bit format and only the last 8 bits of the 16- bit integer are used. The Thumbnail EDR is a sized down version of the original acquired image (i.e., camera returned pixel data), and size of the binary EDR image data is variable. However, the original acquired image is not always downlinked. The main purpose of a Thumbnail EDR is to provide an image summary using a very low data volume compared to the original image.
3. Sub-frame EDR Sub-frame EDRs are a subset of rows and columns of the 1024 x 1024 full frame image. Sub-frame EDRs are stored as 16-bit signed integers. If 12-to-8 bit scaling is performed, then pixels are stored in 16-bit format and only the last 8 bits of the 16-bit integer are used.
4. Downsampled EDR A downsampled EDR is a smaller version of the 1024 x 1024 full frame or subframed image using the following methods: 1) nearest neighbor pixel averaging, 2) pixel averaging with outlier rejection or 3) computing the median pixel value. Downsampled EDRs are stored as 16-bit signed integers. If 12-to-8 bit scaling is performed, then pixels are stored in 16-bit format and only the last 8 bits of the 16-bit integer are used.
5. Reference Pixels The onboard CCD array has 16 pre-Reference dark pixels (12-bits) located at the beginning and 15 post-Reference dark pixels (12-bits) located at the end of each row. The values of these pixels indicate the bias level of the camera at the time of each observation. The Reference Pixel images were losslessly compressed for downlink. For complex design reasons, the last post-Reference pixel is a copy of the next-to-last post-Reference pixel. Following the last post-Reference dark pixel, at the very end of each row, is the camera hardware serial number (left-shifted by 4 bits if 12-bit data).

Software

MER Camera Payload downlink processing software is focused on rapid reduction, calibration, and visualization of images in order to make discoveries, to accurately and expeditiously characterize the geologic environment around the rover, and to provide timely input for operational decisions concerning rover navigation and Instrument Deployment Device (IDD) target selection. Key software tools have been developed at Cornell University, at JPL by the MIPL, SSV, and APSS groups, at NASA Ames, and at the USGS/Flagstaff. These tools can also be used to process MI images (see below), as well as Navcam and Hazcam images, which have substantial scientific potential in addition to their operational importance.

PDS-labeled images and tables can be viewed with the program NASAView, developed by the PDS and available for a variety of computer platforms from the PDS web site. There is no charge for NASAView.

Media/Format

The data set will initially be delivered and kept online. Upon Mission completion, the Pancam EDRs will be delivered to PDS on DVD.

Data Set Overview

This data set contains data that is used to assess the morphology, topography, and geologic context of each rover site, to determine surface color and mineralogic properties, and to constrain, aerosol physical and radiative properties. The calibration has removed bias, dark current, and flatfield effects from the raw Pancam Science EDRs and resulted in the generation of estimated radiance-on-sensor data from Pancam, in units of W/m^2/nm/sr. No geometric or camera-model calibrations or transformations have been applied. For details, see the MER/Pancam Data Users Guide distributed with the PDS archive.

Processing

MER Camera Payload RDRs are considered Level 3 (Calibrated Data equivalent to NASA Level 1-A), Level 4 (Resampled Data equivalent to NASA Level 1-B), or Level 5 (Derived Data equivalent to NASA Level 1-C, 2 or 3). The RDRs are to be reconstructed from Level 2 edited data, and are to be assembled into complete images that may include radiometric and/or geometric correction.

MER Camera Payload EDRs and RDRs will be generated by JPL's Multimission Image Processing Laboratory (MIPL) under the OPGS subsystem of the MER GDS. RDRs will also be generated by the Athena Pancam Science and Microscopic Imager Science Teams under the SOAS subsystem of the GDS.

RDR data products will be generated by, but not limited to, MIPL using the Mars Suite of VICAR image processing software at JPL, the Athena Pancam Science Team using IDL software at Cornell University and JPL, and the Microscopic Imager Science Team using ISIS software at USGS (Flagstaff) and JPL. The RDRs produced will be processed data. The input will be one or more Camera EDR or RDR data products and the output will be formatted according to this SIS. Additional meta-data may be added by the software to the PDS label.

There may be multiple versions of a MER Camera RDRs.

Data

RDR products generated by MIPL will have a VICAR label wrapped by a PDS label, and their structure can include the optional EOL label after the binary data. RDR products not generated by MIPL may contain only a PDS label. Or, RDR products conforming to a standard other than PDS, such as JPEG compressed or certain Terrain products, are acceptable without a PDS header during mission operations, but may not be archivable.

The RDR data product is comprised of radiometrically decalibrated and/or camera model corrected and/or geometrically altered versions of the raw camera data, in both single and multi-frame (mosaic) form. Most RDR data products will have PDS labels, or if generated by MIPL (OPGS), dual PDS/VICAR labels. Non-labeled RDRs include JPEG compressed products and the Terrain products.

Software

MER Camera Payload downlink processing software is focused on rapid reduction, calibration, and visualization of images in order to make discoveries, to accurately and expeditiously characterize the geologic environment around the rover, and to provide timely input for operational decisions concerning rover navigation and Instrument Deployment Device (IDD) target selection. Key software tools have been developed at Cornell University, at JPL by the MIPL, SSV, and APSS groups, at NASA Ames, and at the USGS/Flagstaff. These tools can also be used to process MI images (see below), as well as Navcam and Hazcam images, which have substantial scientific potential in addition to their operational importance.

PDS-labeled images and tables can be viewed with the program NASAView, developed by the PDS and available for a variety of computer platforms from the PDS web site. There is no charge for NASAView.

Media/Format

The data set will initially be delivered and kept online. Upon Mission completion, the Pancam RDRs will be delivered to PDS on DVD.

Data Set Overview

This dataset contains color mosaics produced from Pancam images of the Mars Exploration Rover mission. These products were generated by Jim Bell and Jonathan Joseph of the Pancam science team.

Processing

Individual raw Pancam Experiment Data Records (EDRs) were calibrated to radiance, radiance factor, and estimated Lambert Albedo following the methods described in BELLETAL2006A. They were then map projected into simple cylindrical and/or vertical projection mosaics using software specifically designed for mosaicking of MER/Pancam images, and developed under the direction of Pancam Payload Element Lead Prof. Jim Bell. The mapping software uses information from the geometric calibration of the cameras to correct for slight lens distortions. Slight variations in lighting conditions among images within a mosaic have been corrected using small automated and/or manual multiplicative scaling of individual frames to achieve output mosaics that are as seamless as possible. Large variations in lighting conditions, for example in mosaics spanning a large range of Martian local solar time or spanning multiple Martian days, have not been corrected.

Additional post-processing using commercial image processing tools like Adobe Photoshop has been applied to many of these mosaics in order to filter out single or small groups of 'hot pixels' or to attempt to manually correct particularly harsh seam boundaries. For some mosaics including the horizon, choppy or limited coverage of the sky has been replaced with a representation of the way the sky would have appeared if the coverage had been complete, using actual sky colors from the data's original partial sky coverage.

These archived mosaics were created primarily for public education and outreach purposes, and have been created in false color, approximate true color, and red/blue 3-D anaglyph representations. Substantial additional information and details about these mosaics can be found online on the Pancam Home web site at http://pancam.sese.asu.edu/, following the 'Images' link. Additional details about true color representations of the Martian landscape can be found in BELLETAL2006A and BELLETAL2006B. While they can serve some potential scientific interests (such as basic assessments of geology and geomorphology), because of the sometimes rather qualitative post-processing applied to many of these Pancam mosaics, they should not be used for quantitative image analysis work.

File Naming

The PDS file naming scheme adopted for these mosaics begins with either a target name assigned by the MER team, the name of the large-format mosaic or panorama assigned by the MER team, or a simple sol, rover (A = Spirit, B = Opportunity), and Pancam sequence designator (Pnnnn). This is often followed by a brief indicator of the specific camera (L = left or R = right) and filter (numbers 1-7) indicator, using the filter designation codes described in BELLETAL2003. Finally, a designator is often provided to identify the image as a false color composite (F), an approximate true color composite (ATC), or an anaglyph (ANA or STEREO) intended to be viewed with red/blue glasses (red on the left).

For example:

• SOL2642B_P2354_L257F: Opportunity sol 2642, Pancam sequence 2354, left camera, false color composite RGB from filters L2, L5, and L7.
• SOL661A_P2401_L256ATC: Spirit sol 661, Pancam sequence 2401, left camera, approximate true composite RGB from filters L2, L5, and L76.
• THANKSGIVING_STEREO: The Spirit rover's 'Thanksgiving Panorama', details of which can be found at http://pancam.sese.asu.edu/, following the 'Images' link, choosing the '360 deg. Panoramas' link, then clicking on the 'Thanksgiving Pan' link.
• BURNS_CLIFF_L257F.TIF: The Opportunity rover's 'Burns Cliff' mosaic, details of which can be found at http://pancam.sese.asu.edu/, following the 'Images' link, choosing the 'Small Panoramas and Mosaics' link, then clicking on the 'Burns Cliff 180 deg.' link. This is a false color mosaic acquired in the Pancam left camera's filters L2, L5, and L7.

Point of Contact for more details

Prof. Jim Bell
School of Earth and Space Exploration
Arizona State University
Box 876004, Tempe, AZ 85287-6004
email: Jim.Bell@asu.edu
Office: (480) 965-1044

Data Set Overview

A Mars atmospheric opacity data product consists of two files, an ASCII formatted detached PDS label file and an ASCII formatted data file. The data file contains values of the Mars atmospheric opacity or optical depth derived from MER Pancam images of the Sun acquired with the two solar filters. The effective wavelengths of these filters are 440 and 880 nm. Each data file contains an ASCII table of the derived atmospheric opacity for a given rover and Pancam solar filter. Each table contains columns with the source Pancam image identifier, the time of image acquisition, the Mars season (Ls), Sun-Mars distance, airmass, observed solar flux, and opacity.

Processing

MER Pancam Atmospheric Opacity RDRs are considered Level 5 or Derived Data (equivalent to NASA Level 2). The Mars atmospheric opacity data products are generated from analysis of MER Pancam images.

The Mars atmospheric opacity data products are produced by the Atmospheres Science Theme Group (STG) of the MER Science Operations Working Group (SOWG) using processing procedures and software developed by Mark Lemmon, Texas A&M University.

The data product is generated after each sol in which opacity data is acquired. The generation is done in four steps. First, the input parameters are set up. A list of Pancam data products to be processed is read and associated values are determined for Ls, the distance of Mars from the Sun, the sol that the data were acquired, and the actual elevation angle of the Sun. It is likely that standard tools such as the NAIF toolkit will be used for these computations. For each Pancam data product, the airmass is computed by integration through a spherically symmetric atmosphere with a scale height equivalent to the gas scale height of the Martian atmosphere.

Second, the solar flux is extracted from each calibrated Pancam data product. To do this, the background is determined within an annulus at a fixed radius from the center of the Sun in the image. That background is subtracted, as it would lead to a significant departure from Beers' Law at high airmasses. After background subtraction, the solar flux is integrated over the image. The presence of a few missing pixels (e.g., a Phobos transit or a missing packet that only partly overlaps the Sun) can be accommodated by the integration algorithm. The presence of a large number of missing pixels or any saturated pixels will result in the rejection of an image (returning a flux and opacity of -1.000).

Third, a relative calibration is derived. Data from the afternoon of all sols during which more than 1 image was acquired are considered, together with instrumental uncertainties. The published calibration is considered as a single datum with associated uncertainty. The instrument response is varied, and a single best-fit opacity is derived for each afternoon using Beers' Law (I_observed = I_0 exp (-t h), where h = airmass). A best-fitting responsivity is chosen by minimizing the reduced C^2 of the fit.

Fourth, the relative calibration is used to derive opacities. All images are considered, and Beers' Law is applied to every pair of I_observed and airmass. The relative calibration method ensures that (1) substantial calibration uncertainty is not propagated into uncertainty in opacity once sufficient surface data are obtained, and (2) that the processing transfers smoothly from using the laboratory calibration when the first datasets are obtained to using the relative calibration when enough surface data exist.

Data

Each Mars atmospheric opacity data product is structured as two files; a detached PDS label file and a separate data file. Both components are stored as ASCII text. Data within the opacity data file is organized by time with the most recent measurement being appended to the end of the file.

Each Mars atmospheric opacity data product consists of two parts. The first part of the data file contains header information, which includes parameter values used in the opacity computations and column names for the data rows. The second part of the file, starting at line 10 consists of a PDS table object. The table has eight columns and a variable number of rows. There is one row for each opacity measurement. The number of rows in a data product will increase as new measurements of atmospheric opacity are made. Each row is 88 bytes long including the carriage return and line feed characters. All columns are fixed-width as described in the PDS label and are also delimited with commas. Text columns are surrounded by double-quotes and are left-justified. Numeric columns are right-justified.

Software

The ASCII format of the Mars atmospheric opacity data product means that the data can be displayed using a text editor. In addition, the use of the PDS table structure for this data product means the data can be readily imported into spreadsheet and plotting programs.

PDS-labeled tables can be viewed with the program NASAView, developed by the PDS. NASAView is available in versions that run on SUN/SOLARIS, Windows, and LINUX operating systems. NASAView can be obtained from the PDS web site. There is no charge for NASAView.

Media/Format

The data set will initially be delivered and kept online. Upon Mission completion, the Pancam Atmospheric Opacity RDRs will be delivered to PDS on DVD.

Data Set Overview

This data set contains raw Pancam operational data. If 12 to 8 bit scaling was commanded, these images HAVE NOT been transformed back to 12 bits. These images are only used to asses the morphology, topography, and geologic context of each rover site. These images should not be used for quantitative scientific purposes.

Processing

This documentation uses the Committee on Data Management and Computation (CODMAC) data level numbering system. The MER Camera Payload EDRs referred to in this document are considered Level 2 or Edited Data (equivalent to NASA Level 0). 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. They are to be assembled into complete images, but will not be radiometrically or geometrically corrected.

EDR data products will be generated by MIPL using the telemetry processing software mertelemproc at JPL. The EDRs produced will be raw uncalibrated data reconstructed from telemetry packet SFDUs and formatted according to this SIS. Meta-data acquired from the telemetry data headers and a meta-data database will be used to populate the PDS label. Missing packets will be identified and reported for retransmission to the ground as partial datasets. Prior to retransmission, the missing EDR data will be filled with zeros. The EDR data will be reprocessed only after all partial datasets are retransmitted and received on the ground. In these cases, the original EDR version will be overwritten.

Data

The data packaged in the camera data files will be decoded, decompressed camera image data in single frame form as an Experiment Data Record (EDR). The Full Frame form of a standard image data file has the maximum dimensions of 1024 lines by 1024 samples.

1. Full Frame EDR: Full Frame EDRs are stored as 16-bit signed integers. If 12-to-8 bit scaling is performed, then pixels are stored in 16-bit format and only the last 8 bits of the 16-bit integer are used.
2. Thumbnail EDR: Thumbnail EDRs are stored as 16-bit signed integers or 8-bit unsigned integers. If 12-to-8 bit scaling is performed, then pixels are stored in 16-bit format and only the last 8 bits of the 16- bit integer are used. The Thumbnail EDR is a sized down version of the original acquired image (i.e., camera returned pixel data), and size of the binary EDR image data is variable. However, the original acquired image is not always downlinked. The main purpose of a Thumbnail EDR is to provide an image summary using a very low data volume compared to the original image.
3. Sub-frame EDR: Sub-frame EDRs are a subset of rows and columns of the 1024 x 1024 full frame image. Sub-frame EDRs are stored as 16-bit signed integers. If 12-to-8 bit scaling is performed, then pixels are stored in 16-bit format and only the last 8 bits of the 16-bit integer are used.
4. Downsampled EDR: A downsampled EDR is a smaller version of the 1024 x 1024 full frame or subframed image using the following methods: 1) nearest neighbor pixel averaging, 2) pixel averaging with outlier rejection or 3) computing the median pixel value. Downsampled EDRs are stored as 16-bit signed integers. If 12-to-8 bit scaling is performed, then pixels are stored in 16-bit format and only the last 8 bits of the 16-bit integer are used.
5. Reference Pixels: The onboard CCD array has 16 pre-Reference dark pixels (12-bits) located at the beginning and 15 post-Reference dark pixels (12-bits) located at the end of each row. The values of these pixels indicate the bias level of the camera at the time of each observation. The Reference Pixel images were losslessly compressed for downlink. For complex design reasons, the last post-Reference pixel is a copy of the next-to-last post-Reference pixel. Following the last post-Reference dark pixel, at the very end of each row, is the camera hardware serial number (left-shifted by 4 bits if 12-bit data).

Software

MER Camera Payload downlink processing software is focused on rapid reduction, calibration, and visualization of images in order to make discoveries, to accurately and expeditiously characterize the geologic environment around the rover, and to provide timely input for operational decisions concerning rover navigation and Instrument Deployment Device (IDD) target selection. Key software tools have been developed at Cornell University, at JPL by the MIPL, SSV, and APSS groups, at NASA Ames, and at the USGS/Flagstaff. These tools can also be used to process MI images (see below), as well as Navcam and Hazcam images, which have substantial scientific potential in addition to their operational importance.

PDS-labeled images and tables can be viewed with the program NASAView, developed by the PDS and available for a variety of computer platforms from the PDS web site. There is no charge for NASAView.

Media/ Format

The data set will initially be delivered and kept online. Upon Mission completion, the Pancam EDRs will be delivered to PDS on DVD