HEADER

        LAS\HEADER

    Displays  some  header information on the R Observation. The FULL format
    is used, with the informations selected in command SET  FORMAT  written.
    The lines written contain (in output order, but not all lines are neces-
    sarily present)
    - General information line:
        Scan number and version
        Source name
        Line name
        Telescope name
        Date of observation
        Date of last reduction
    - Position information line
        RA or l        right ascension or longitude (or azimuth)
        DEC or b       declination or latitude (or elevation)
        Epoch          if equatorial coordinates are used
        Offsets        (in current units)
        coordinate     Eq, Ga, Az
    - Quality information line:
        Quality of calibration (as defined by a SET QUALITY)
        Tau      opacity at zenith
        Tsys     system temperature (outside atmosphere).
        Time     total integration time on source (minutes)
        El       elevation of source
    - Spectral information lines (2):
        N        number of channel
        I0       reference channel (real)
        V0       velocity at reference channel
        Dv       velocity resolution (signed)
        F0       rest frequency at reference channel
        Df       frequency resolution (signed)
        Fi       image frequency at reference channel
    - Calibration information line:
        B_ef    Beam efficiency of telescope
        F_ef    Forward efficiency of telescope
        G_im    Gain in image band
    - Atmospheric information lines (2):
        H2O      millimeter of precipitable water vapor
        Pamb     ambient pressure
        Tamb     ambient (receiver cabin) temperature
        Tchop    Chopper temperature
        Tcold    Cold load temperature
        Tatm     Atmospheric temperature in the signal band
        Tau      Zenith opacity in the signal band
        Tatm_i  Atmospheric temperature in the image band
        Tau_i   Zenith opacity in the signal band
    - Continuum Drift information lines (2) :
        N        Number of points
        I0       Reference point
        A0       Angle offset at reference point
        Da       Angular spacing between points (signed).
        F0       Observing frequency
        Df       Band pass
        Pos. Ang. : Position angle of the drift.
    followed by the list of Scan numbers added in the observation.