Data Set Overview
  =================
    The MIPLRAD method refers to radiometric correction systematically
    performed by MIPL (OPGS at JPL) to meet tactical time constraints
    imposed by rover planners, since these RDRs are integrated into
    terrain mesh products used for traverse planning. The method can
    apply to any of the camera instruments.

    In the operations environment for the Prime and Extended Missions,
    MIPL's radiometrically-corrected RDR filename carries the product
    type designator of RAD for the non-linearized case and RAL for
    the linearized case. However, in the PDS archive volume, the MIPL
    radiometrically-corrected RDR carries the product type MRD for the
    non-linearized case and MRL for the linearized case. Though there
    is no difference in image content between the operational and
    archived versions of MIPL's radiometrically-corrected RDR, the
    distinction in their filenames is made to identify all RAD and
    RAL product types in the PDS archive volumes as being unique to
    the Athena Pancam team's radiance correction process.

    As a special note, two bugs pertaining to MIPL's radiometric
    correction process were discovered during the preparation of data
    for PDS archival, which was after the MER Prime Mission and well
    into the Extended Mission. The problems involved on-board flat-field
    removal and temperature determination. For the purposes of this
    discussion, the term MIPLRAD refers to the original implementation
    used during Prime Mission and approximately through the first two
    months of Extended Mission, while MIPLRAD2 represents the corrected
    implementation used thereafter. Both MIPLRAD and MIPLRAD2 are valid
    values for RADIOMETRIC_CORRECTION_TYPE. The differences are
    described below. Note that all RAD/RAL/RSD/RSL types of RDRs have
    been reprocessed with MIPLRAD2, limiting the number of
    MIPLRAD-processed products in the PDS archive volume to a subset of
    mosaics which were generated before MIPLRAD2 was implemented. Note
    also that no mosaics were generated from on-board flat-field images
    using MIPLRAD, so the only difference in the archive data is the
    temperature issue.

    MIPLRAD is a first-order correction only and should be considered
    approximate. MIPLRAD first backs out any onboard flat field that was
    performed. It then applies the following corrections: flat field,
    exposure time, temperature-compensated responsivity. The result is
    calibrated to physical units for MER of W/m^2/nm/sr. The actual
    algorithm and equations used for MIPLRAD are shown below. Each
    correction is applied in sequence, to every pixel:

    1. If on-board flat-fielding has been applied, it is backed out
       according to the parameters in FLAT_FIELD_CORRECTION_PARM, which
       defines ff(x,y). MIPLRAD incorrectly multiplied by ff(x,y) rather
       than divided, causing the on-board flat field to be doubled
       rather than removed. MIPLRAD2 correctly divides by ff(x,y) as
       follows:

       output(x,y) = input(x,y) / ff(x,y)

    2. For the flat-field adjustment, the x and y coordinates are
       adjusted based on downsampling and subframing to find the
       corresponding pixel in the flat field, then the DN is divided by
       the flat field value:

       output(x,y) = input(x,y) / flat_field(x',y')

    3. Exposure time is then removed. Exposure time comes from
       EXPOSURE_DURATION, converted to seconds:

       output(x,y) = input(x,y) / exposure_time

    4. The temperature responsivity is removed next. The temperature
       comes from the first element of INSTRUMENT_TEMPERATURE and the
       parameters R0, R1, and R2 come from the flat field parameter
       file, and are different per instrument. The actual temperature
       formula is as follows:

       output(x,y) = input(x,y) * (R0 + R1*temp + R2*temp*temp)

    For MIPLRAD, the temperature is simply the first element of
    INSTRUMENT_TEMPERATURE. For MIPLRAD2, the temperature is dependent
    on the instrument. The temperature used for each instrument is
    determined using the following general rules
    (from the MER thermal team):

    a) Use the CCD temp of said camera, if it exists.

    b) Use the CCD temp of neighboring camera (left/right partner), if
       available.

    c) Use the CCD temp of similar camera (i.e., Navcam/Pancam).

    d) Use CCD temperature from any camera.

    e) Use the electronics temperature of said camera.

    f) Use the electronics temperature of similar camera.

    Rules e and f are a last resort in view of the fact that MER
    operates warmup heaters inside the electronics (during nighttime and
    early morning) that raise camera electronics temperatures above CCD
    temperatures. Thus any CCD temperature is at higher priority than
    any electronics temperature measurement. The most significant
    consequence of this is that the MI CCD is the best available proxy
    for all four Hazcam CCDs. A value of 0.0 is ignored as a no-reading
    value, and a value greater than or equal to 50.0 (degrees C) is
    interpreted as a broken sensor. Either value causes that temperature
    to be ignored and the next one on the list tested. If none of the
    values is valid, a default of 0.0 degrees C is used.


  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.

    The MIPLRAD method is a radiometric correction performed by MIPL
    (OPGS) at JPL. It can apply to any of the camera instruments, but
    only the RAD (and RAL) type is generated. MIPLRAD first backs
    out any onboard flat field that was performed. It then applies the
    following corrections: flat field, exposure time,
    temperature-compensated responsivity. The result is calibrated to
    physical units for MER of W/m^2/nm/sr. MIPLRAD is a first-order
    correction only and should be considered approximate.


  Software
  ========
    The MIPL Mars Program Suite was used to generate these RDRs.


  Media/Format
  ============
    The data set will initially be delivered and kept online.  Upon
    Mission completion, the Microscopic Imager Operations RDRs will be
    delivered to PDS on DVD.

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