SV sentence in the GSV
        sequence.
    @ivar timestamp: A timestamp. (C{"123456"} -> 12:34:56Z)
    @ivar datestamp: A datestamp. (C{"230394"} -> 23 Mar 1994)
    @ivar latitudeFloat: Latitude value. (for example: C{"1234.567"} ->
        12 degrees, 34.567 minutes).
    @ivar latitudeHemisphere: Latitudinal hemisphere (C{"N"} or C{"S"}).
    @ivar longitudeFloat: Longitude value. See C{latitudeFloat} for an
        example.
    @ivar longitudeHemisphere: Longitudinal hemisphere (C{"E"} or C{"W"}).
    @ivar altitude: The altitude above mean sea level.
    @ivar altitudeUnits: Units in which altitude is expressed. (Always
        C{"M"} for meters.)
    @ivar heightOfGeoidAboveWGS84: The local height of the geoid above
        the WGS84 ellipsoid model.
    @ivar heightOfGeoidAboveWGS84Units: The units in which the height
        above the geoid is expressed. (Always C{"M"} for meters.)
    @ivar trueHeading: The true heading.
    @ivar magneticVariation: The magnetic variation.
    @ivar magneticVariationDirection: The direction of the magnetic
        variation. One of C{"E"} or C{"W"}.
    @ivar speedInKnots: The ground speed, expressed in knots.
    @ivar fixQuality: The quality of the fix.
    @type fixQuality: One of L{GPGGAFixQualities}.
    @ivar dataMode: Signals if the data is usable or not.
    @type dataMode: One of L{GPGLLGPRMCFixQualities}.
    @ivar numberOfSatellitesSeen: The number of satellites seen by the
        receiver.
    @ivar numberOfSatellitesUsed: The number of satellites used in
        computing the fix.
    @ivar horizontalDilutionOfPrecision: The dilution of the precision of the
        position on a plane tangential to the geoid. (HDOP)
    @ivar verticalDilutionOfPrecision: As C{horizontalDilutionOfPrecision},
        but for a position on a plane perpendicular to the geoid. (VDOP)
    @ivar positionDilutionOfPrecision: Euclidean norm of HDOP and VDOP.
    @ivar satellitePRN: The unique identifcation number of a particular
        satellite. Optionally suffixed with C{_N} if multiple satellites are
        referenced in a sentence, where C{N in range(4)}.
    @ivar elevation: The elevation of a satellite in decimal degrees.
        Optionally suffixed with C{_N}, as with C{satellitePRN}.
    @ivar azimuth: The azimuth of a satellite in decimal degrees.
        Optionally suffixed with C{_N}, as with C{satellitePRN}.
    @ivar signalToNoiseRatio: The SNR of a satellite signal, in decibels.
        Optionally suffixed with C{_N}, as with C{satellitePRN}.
    @ivar usedSatellitePRN_N: Where C{int(N) in range(12)}. The PRN
        of a satellite used in computing the fix.
    c