In this we first process the data into a secondary file, perform a RF passband calibration to be able to average continuum subbands and sidebands more accurately, and solve for the baseline with a search loop.
! FILE I INTER_DATA:01-dec-1992 ! Load the raw data SET SCAN 2393 2440 ! select data by scan number SET PROCEDURE CORR ! only correlations FIND LIST ! as a check FILE O W00-N15-E23 NEW ! open a secondary data file COMPRESS 60 ! compress to 1 minute, ! (this saves plotting time) ! ! Select the compressed data file and do passband calibration on 3c273 ! FILE BOTH W00-N15-E23 ! reopen for both input and output FIND PLOT ! giving it a glance does not hurt ... SET SOURCE 3C273 ! the strongest souce SET MODE SPEC ! actually not needed SET X I_F ! SET PHASE CONTINUOUS ! SET RF FREQUENCY ! use frequency dependent mode SET Y AMPLITUDE PHASE SET SUBBANDS L01 TO L06 FIND LIST SET BANDS UPPER ! do upper side band fist SOLVE RF_PASSBAND 5 10 /PLOT ! degrees as actually needed ... SET BANDS LOWER ! Then lower side band SOLVE RF_PASSBAND 5 10 /PLOT SET SOURCE * ! come back to all sources FIND STORE RF_PASSBAND ! in place, in the data headers ! ! Now solve for baseline, using average of subbands 1 to 6 ! SET RF_PASSBAND ON FR ! from now on, plot calibrated data SET MODE TIME ! switch back to time mode SET SUBBANDS C01 TO C06 ! now subbands may be averaged SET PHASE JUMPY ! best for baseline solving SET Y PHASE ! amplitude not needed SET X HOUR_ANGLE DECLINATION SET BANDS AVERAGE ! double side band PLOT ! phases should be displayed SOLVE BAS/SEARCH ! should normally be enough. ! ...wait a few seconds ... PRINT BASELINE PAUSE ! keep a log of the results ! RESIDUALS BASELINE ! phases should be flat.