Basic Information on opplt

Task: opplt
Purpose: Plot opacity and sky brightness.
Categories: miscellaneous

        Opplt plots model opacity and atmospheric brightness temperatures
        given site information. These quantities can be plotted as a function
        of frequency or elevation.
 
        To plot as a function of frequency, give two values for the
        freq key and one for the el key.
 
        To plot as a function of elevation, give two values for the
        el key and one for the freq key.
 
        You must give two values for either freq or el.
 

Key: freq
        Frequency range of interest, in GHz. One or two values can be given.
        If two values are given, then the plot is as a function of frequency,
        and the values are the limits for the plot.
        The default is 22 GHz.

Key: el
        Elevation angle, in degrees. One or two values can be given.
        If two values are given, then the plot is as a function of elevation,
        and the values are the limits for the plot.
        The default is 90 degrees (i.e. zenith).

Key: device
        Plot device. Default is not to plot anything.

Key: log
        Output log file. The default is not to create one.

Key: options
        Extra processing options. Currently there is only a single option.
          airmass  When plotting as a function of elevation, express the
                   x-axis as cosec(elevation), which is also known as the
                   airmass.

Key: t
        Temperature, in Kelvin. Default is 300.

Key: z
        Observatory altitude, in m. Default is 200 (i.e. the
        altitude of Narrabri).

Key: p
        Sea-level atmospheric pressure, in hPa (i.e. millibars). The default
        is 1013 hPa.

Key: h
        Relative humidity, as a percentage. The default is 20%.