PARAMETER

        [POINT\]PARAMETER NAME [Value] [/FREE]

         Fix a fit parameter at the specified value, or free  the  specified
    parameter if option /FREE is present.  Value is in arcsecond.  Available
    parameters are
          IAZ     Zero azimuth
          IEL+COV Zero elevation
          COH     Azimuth collimation
          MVE     East Inclination
          MVN     North Inclination
          NPE     Non perpendicularity
          REF1    1st order refraction
          REF2    2nd order refraction
          ELES    grav.+exc. coder ele. (sin)
          ELEC    grav.+exc. coder ele. (cos)
          AZES    excen. coder az. (sin)
          AZEC    excen. coder az. (cos)
    REF1 and REF2 are preset to 0 and 0 by default, because  on  Plateau  de
    Bure  the  refraction  is  computed in real from meteo parameters.  They
    should not be freed, except for very specific purposes.