The Miriad task smatbpass removes time-dependent bandpass ripples. smatbpass reads multiple files (bpfile) containing antenna-based bandpass solved using either smamfcal or mfcal in time intervals at different time. The bandpasses are interpolated or extrapolated to a time with either linear fit from the two nearby solution points or orthogonal polynomial fit from all the solution points in the input bpfiles. Here is a usage of smatbpass:
Task: smatbpass bpfile = 05aug1bp % root name of input files each of which contains bandpass solutions in the bandpass table at the corresponding time in the gain table. nfiles = 3 % The number of bandpass files (bpfile) to read. vis = sgrb228a_rx0.lsb.tsys % The name of the input uv data sets. bptime = 30 % The time interval, in minutes, to interpolate/extrapolate the bandpass solutions. options = nocal % extra options out = sgrb228a_rx0.lsb.tsys.bp % The name of the output uv data set which has been applied for bandpass correction.
The visibility data in output file sgrb228a_rx0.lsb.tsys.bp has been corrected for the bandpass ripples.