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.