Data Set Overview
  =================
    This data set contains images acquired by the Hazcams for the suport
    of rover traverse planning, post-traverse assessment, rover
    localization, operation of the instrument arm, and the selection of
    science targets. Most Hazcam images were commanded via ground
    commands from Earth, although a subset of Hazcam images were
    commanded autonomously during rover traverses by the Rover onboard
    autonomous navigation system. The proximity of the Hazcams to the
    Martian surface has resulted in a set of close-up views of the
    fine-grain texture of materials in the immediate vicinity of the
    rover. Hazcam image data often provide views of the surface not
    viewable by the Navcam and Pancam cameras.


  Processing
  ==========
    This data set uses the Committee on Data Management and
    Computation (CODMAC) data level numbering system. The MER Camera
    Payload EDRs are considered Level 2 or Edited Data (equivalent
    to NASA Level 0). The EDRs are 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 are not radiometrically or
    geometrically corrected.

    Hazcam EDR data products were generated by the Multi-mission Image
    Processing Lab at the Jet Propulsion Laboratory using the telemetry
    processing software mertelemproc. The EDRs produced are raw
    uncalibrated data reconstructed from telemetry packet SFDUs 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 populate the PDS label. There
    will not be multiple versions of a MER Camera Payload EDR. Missing
    packets will be identified and reported for retransmission to the
    ground as partial datasets.


  Data
  ====
    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 spatially
       downsampled version of the original acquired source image (all
       EDRs for a particular image are derive from the same source
       image). For example, in the case of subframe image products the
       thumbnail image represents the full-frame contextual image form
       which the subframe image data was extracted from. Note that the
       original acquired image is not always downlinked, and in some
       cases thumbnails are the only returned data for a particular
       observation. The main purposes of a Thumbnail EDR are to provide
       image previews and contextual information, both at 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.


  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 JPL by the Multimission Image Processing
    Laboratory (MIPL). These tools were also used to process Pancam
    and MI images.

    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
    http://pdsproto.jpl.nasa.gov/Distribution/license.html.
    There is no charge for NASAView.


  Media/Format
  ============
    The data set will initially be delivered and kept online. Upon
    Mission completion, the Hazard Avoidance Camera EDRs will be
    delivered to PDS on DVD as part of the complete MER EDR data set.

NULL