Documentation on pops

Task: pops
Purpose: Convert position to another epoch.
Categories: utility

        POPS is a Miriad task which converts equatorial positions
        from one epoch to another. Accuracy is about 1 arcsec.
        If an observatory is also given, POPS
        gives other source information, such as radial velocity, source
        rise and set time and source elevation and azimuth. 

Key: radec
        Right ascension and declination, given as hh:mm:ss,dd:mm:ss.
        These coordinates are assumed to be mean coordinates of the given
        epoch. The mean, true and apparent coordinates are printed on output.

Key: epochs
        The input and output epochs. The epochs can be given as either
        Bxxxx or Jxxxx (where xxxx is a year, e.g. B1950 or J2000), or as
        yymmmdd:hh:mm:ss, a time in normal Miriad format 
        (e.g. 93JAN05:10:25:00).

Key: observ
        Observatory name. Default is the geocenter.