3 dimensional data stored in the .cub file

basic structure

Three dimensional data is stored in a file with the extension ".cub". A file corresponds to a single cube data extending 3 dimensions. The file is dirctly managed by UNIX-OS or Linux-OS. Therefore you can easily mv, cp, rm, ls. The file contains actural values of data and additional data as "header".

headers

A .cub file and flow has the following information in its header. The following number, name, etc. shows the type or possible selection.
They correspond a member of structure in the C-language but not the same name. See depevolper's page in detail.

  1. Section "System Header"
    This is the same as in the .scn file.
  2. Section "Observation Paramter"
    This is the same as in the .scn file.
  3. Section "Object Information"
    This is the same as in the .scn file.
  4. Section "Telescope/Antenna Information"
    This is the same as in the .scn file.
  5. Section "Receiver Information"
    This is the same as in the .scn file.
  6. Section "Beckend/Detector Information"
    This is the same as in the .scn file.
  7. Section "Observation Log"
    This is the same as in the .scn file.
  8. Section "Axis"
    dimension number
    The number of axes in the data. At present this must be 3.
    order 'xyz'
    The order of axes in the file address. The first character is the axis of the least significant address changing. The last character is the axis of the most significant address changing.
    x,y,z axes in this order
    axis_name name
    The name or label of the axis. Less than or 16 characters.
    l - Galactic longitude
    b - Galactic latitude
    RA - Right Acsension
    Dec - Declination
    az - azimuth
    el - elevation
    v - velocity
    size number
    The number of elements along the axis.
    axis_type type_name
    The name of axis type. Less than or 8 characters.
    long - longitude
    lat - latitude
    velocity - velocity
    freq - frequency
    unit unit_name
    The unit of the axis. Less than or 8 characters.
    pixel - simple ordering
    degree - degrees for longitude and latitude
    km/s - kilometer per second for velocity
    project type
    ID name of projection type. Less than or 8 characters. Most of the same as FITS projection ID.
    linear - as is
    arc - the same as linear (recommend to use the word, linear)
    tan - Gnomic
    sin - Orthographic
    stereo - Sterographic
    Mercator - Mercator
    Sinusoid - Sinusoidal
    Parabol - Paraboloid
    Aitoff - Aitoff
    Molweide - Molweide
    refer ID_name
    ID name of reference of the coordinate. Some are copied from EQUINOX or EPOCH in FITS keyword. Less than or 8 characters.
    lb1 - old galacitic coordinate (lb-I)
    lb2 - (new) galactic coordinate (lb-II)
    B1950.0 - 1950.0 equinox in Bessel year
    J2000.0 - 2000.0 equinox in Julian year
    LSR - local standard of rest
    helio - heliocentirc velocity
    delta value_in_axis_unit
    The interval of the pixel.
    origin value_in_axis_unit
    The position of the referred pixel in the axis unit.
    pixel_origin value_in_pixel
    The address of the referred pixel used as origin. The smallest address stored in the cub file is 0, not 1.
    rotation value_in_degree
    The rotation angle of the axis from the axis_name direction.
    resolution value_in_axis_unit
    The effective resolutation of the data along the axis.
    point_spread_function name_of_function
    The function name of the point spread function along the axis.
    gauss - Gaussian
    box - boxcar
    original_resolution value_in_axis_unit
    The original resolution of the data along the axis.
  9. Section "Data Value"
    type type_name
    The type name of the data. Less than or 8 charactors.
    Ta* - corrected antenna temperature
    unit unit_name
    The unit of the data. Less than or 8 characters.
    K - Kelvin
    scale value
    scaling factor for the data. A for phys_value=A*pixel_value+B.
    offset value
    offset value for the data. B for phys_value=A*pixel_value+B.
    dummy value
    Pixel value for blank pixel.
    max value
    Maximum pixel value for the data.
    min value
    Minimum pixel value for the data.
    mean value
    Mean pixel value for the data.
    rms value
    Root mean square of the data in pixel value.
    noise value
    RMS noise level of the data in pixel value.
  10. Section "Processing History"
    This is the same as in the .scn file.
  11. Section "Profile Data"
    **data
    Actual 3 dimensional cube data. The array is allocated as a memory address array of memory addresses, which are called as "pointers" in C-language. To access for the data you should use functions of UltarSTAR standard libraries, such as StarGetCubeData(), StarPutCubeData(). The address number in pixel starts from 0, not from 1.

SEE ALSO

cubheadls

BUGS

HISTORY

ver.4
1999/7/28 T.Handa

MANUAL VERSION

1999/12/27 T.Handa