The Ralph experiment consists of two channels, the Multispectral Visible Imaging Camera (Ralph MVIC) and the Linear Etalon Imaging Spectral Array (Ralph LEISA). The main objectives are to obtain high-resolution color maps and surface composition maps of Pluto and Charon, including global dayside four-color maps at 0.7 km/pixel resolution, dayside hyper-spectral near-infrared maps at 7 km/pixel globally and 0.6 km/pixel for selected areas, and maps of dayside surface ice distribution and temperatures.

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REQUIRED READING:
- Reuter et al. (2005) [REUTERETAL2005]
- Reuter et al. (2007) [REUTERETAL2007]
- SOC Instrument Interface Control Document (ICD)
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      The MVIC description was was adapted from Reuter et al. (2005)
      [REUTERETAL2005], the MVIC section of the SOC Instrument ICD
      (provided in the documentation with this archive), Reuter et al.
      (2007) [REUTERETAL2007] (also provided with this archive), and
      the New Horizons website.
 
 
  Instrument Overview
  ===================
    MVIC is an imager that operates at both visible and near-infrared
    wavelengths using seven separate Charge-Coupled Device detectors
    (CCDs).  Four CCDs have color filters (methane, red, blue and
    near-infrared) for producing color maps and three CCDs have
    panchromatic filters for observations where maximum sensitivity to
    faint light levels is required.  In all cases, the light passes from
    the telescope through a filter and is focused onto the CCDs.
 
    MVIC is integrated with another instrument, LEISA, into a composite
    instrument named RALPH, which supplies A/D conversion, command and
    data handling, and power to both MVIC and LEISA.
 
 
    Specifications
    --------------
      NAME:                    MVIC (Multispectral Visible Imaging Camera)
      DESCRIPTION:             Imaging camera
      PRINCIPAL INVESTIGATOR:  Alan Stern, SwRI
      WAVELENGTH RANGE:        (Note 1)
      FIELD OF VIEW:           100 x N mRad (Note 2); 100 x 2.6 mRad
                                 (Note 3)
      ANGULAR RESOLUTION:      0.02 mRad/pixel
      WAVELENGTH RESOLUTION:   See filter bandpasses (Note 1)
 
      Note 1:  See Filters section below for Wavelength
               ranges and filter bandpasses.
 
      Note 2:  Time-delay integration (color and two panchromatic arrays).
      The length of the scan determines the dimension of the scan denoted
      by N.
 
      Note 3:  Pan frame array only.
 
 
    General Description
    -------------------
      MVIC uses two large format (5024x32 pixel) CCD arrays to provide
      panchromatic hemispheric maps of Pluto at a double-sampled spatial
      resolution of 1 km by 1 km or better.  Four additional 5024x32 CCDs
      provide hemispheric maps in blue, red, Near IR and narrow band
      methane color channels.  These 6 arrays all operate in Time Delay
      Integration (TDI aka pushbroom) mode to increase sensitivity.  In
      addition to the TDI arrays, MVIC has a 5024x128 pixel frame transfer
      array.  For each of the arrays, the 12 pixels at either end of the
      rows are not opically active.
 
 
  Scientific Objectives
  =====================
    Hemispheric panchromatic maps of Pluto and Charon at a resolution
    better than 0.5 km/pixel
 
    Hemispheric 4-color maps of Pluto and Charon at a resolution better
    than 5 km/pixel
 
    Search for and map atmospheric hazes at a vertical resolution better
    than 5 km/pixel
 
    High resolution panchromatic maps of the terminator region
 
    Panchromatic, wide phase angle coverage of Pluto, Charon, Nix, and
    Hydra
 
    Panchromatic stereo images of Pluto and Charon, Nix, and Hydra
 
    Orbital parameters, bulk parameters of Pluto, Charon, Nix, and Hydra
 
    Search for rings
 
    Search for additional satellites
 
 
  Detectors
  =========
    MVIC comprises seven independent CCD arrays on a single-substrate
    focal plane.  It uses two of its large format (5024x32 pixels i.e. 32
    rows each 5024 pixels wide) CCD arrays, operated in TDI mode, to
    provide panchromatic images.  Four additional 5024x32 CCDs, combined
    with the appropriate filters and also operated in TDI mode, provide
    the capability of mapping in blue, red, near-IR and narrow-band
    methane channels.
 
    TDI operates by synchronizing the parallel transfer rate of each of
    the CCDrows to the relative motion of the image across the surface of
    the detector.  In this way, very large format images are obtained as
    the spacecraft scans the FOV across the surface of a target.  The
    presence of 32 rows increases the effective integration time by that
    same factor, providing high signal-to-noise measurements.  The
    measured spacecraft rotation rate can be fed back to the instrument to
    optimize the frame transfer rate.  That is, after a scan has been
    initiated, the spacecraft determines the actual rotation rate and
    sends that information to RALPH, which uses it to calculate the frame
    rate that minimizes smear in the along-track direction.
 
    MVIC always produces image data in correlated double-sample (CDS)
    mode; that is, the reset level is subtracted from the integrated level
    and the difference is returned as the image.
 
 
  Electronics
  ===========
    The RALPH control electronics comprise three boards:  the detector
    electronics (DE) board; the command and data handling (C&DH) board;
    the low voltage power supply (LVPS) board.  These are contained within
    an electronics box (EB) mounted directly on the spacecraft, and
    operate essentially at the spacecraft surface temperature, which is
    near ambient.  The DE board provides biases and clocks to both MVIC
    and LEISA focal planes, amplifies the signals from the arrays and
    performs the A/D conversion of the electrical charge of each pixel to
    a digital number with 12 bits of resolution.  The C&DH board
    interprets the commands, performs the A/D conversion of the low-speed
    engineering data and provides both the high-speed image data interface
    and the low-speed housekeeping data interface.  The LVPS converts the
    30V spacecraft power to the voltages required by RALPH.
 
    In a long-duration mission such as New Horizons, reliability of the
    electronics is of paramount importance, particularly for a core
    instrument that addresses all major mission objectives.  To ensure
    that RALPH is robust, almost all of the electronics are redundant.
    RALPH can operate on two separate sides (side A or B) which have very
    few components in common.  The only common elements are: 1) the relays
    that choose whether side A or side B is to be powered, 2) The arrays
    themselves and 3) the interface to the spacecraft.  However, the
    spacecraft interface has two identical circuits and is inherently
    redundant.  For MVIC, the potential single point failure mode of the
    arrays is mitigated by dividing the six TDI arrays into two groupings,
    each containing two color CCDs and one panchromatic CCD.  The first
    grouping comprises a pan band and the red and CH4 channels.  The
    second grouping comprises the other pan band and the blue and NIR
    channels.  If either group should fail, the other would still be able
    to meet the science requirement of observations in two color bands and
    one panchromatic band.
 
 
  Filters
  =======
    From Reuter et al. (2007)
 
      _Bandpass__   Filter designation
 
      400 - 975nm  Panchromatic (PAN)
      400 - 550nm  Blue
      540 - 700nm  Red
      780 - 975nm  NIR
      860 - 910nm  CH4
 
    For more details see the individual filter transmission curves in the
    /CALIB/ directory.
 
 
  Optics
  ======
    See description above.  Also:
 
    The FOV of a single MVIC pixel is 20x20 microradian^2.  The
    panchromatic (pan) channels of MVIC will be used to produce
    hemispheric maps of Pluto and Charon at a double-sampled spatial
    resolution of 1 km^2 or better.  The static FOV of each of the TDI
    arrays is 5.7 degrees x 0.037 degrees.  In addition to the TDI arrays,
    MVIC has a 5024x128 element, frame transfer panchromatic array
    operated in staring mode, with an FOV of 5.7 degrees x 0.15 degrees.
    The primary purpose of the framing array is to provide image data for
    optical navigation of the spacecraft.
 
 
  Operational Modes
  =================
    RALPH-MVIC modes are intertwined with RALPH-LEISA modes.  See Reuter
    et al.  (2007) [REUTERETAL2007], Section 7.0 'IN-FLIGHT INSTRUMENT
    OPERATION' for details.
 
 
  Calibration
  ===========
    See Reuter et al. (2007) [REUTERETAL2007], especially sections 5 and 6.
 
 
  Measured Parameters
  ===================
    Radiance; errors less than one DN as of 20.April 2007.  See Reuter et
    al. (2007) [REUTERETAL2007] section 6.0 COMBINED 'PRE-LAUNCH AND
    IN-FLIGHT INSTRUMENT CALIBRATION RESULTS' for more details.

extracted metadata from PDS3 catalog and
                    modified to comply with PDS4 Information Model

NH Multispectral Visible Imaging Camera (MVIC/RAPLH)

Description

Identifier (LID)

Version