;+ ; This procedure retrieves the "cal" signal from a cal-switched scan. ; ;

This code can be used as a template for the user who may wish to ; develop more tailored calibration schemes. ; ;

Summary ;

;

Parameters ;

; The scan number is required. Arguments to identify the ; IF number, polarization number and feed number are optional. The ; procedure calculates Tsys based on the Tcal values and the data. ; The Tcal value comes from the mean_tcal value in cal_off phase data ; container unless the user supplies a value using the tcal keyword. ; In that case, one tcal value is supplied and that value is used for ; all integrations processed here. The two switching phases are ; differenced and a system temperature (Tsys) is calculated in the ; docal procedure. ; See the documentation for that procedure for details of the Tsys ; calculation. ;

;

If ifnum, fdnum, or plnum are not supplied then the lowest ; values for each of those where data exists (all combinations may not ; have data) will be used, using any user-supplied values. The value ; of ifnum is determined first, followed by fdnum and finally plnum. If a ; combination with data can not be found then showiftab ; is used to show the user what the set of valid combinations are. ; The summary line includes the ifnum, fdnum, and plnum used. ;

; Weighting of Integrations in Scan Average ;

; By default, the averaging of integrations is weighted using ; tsys, exposure, and frequency_resolution as described in the ; dcaccum documentation. To give all integrations equal ; weight instead of the default weighting based on Tsys, use the ; /eqweight keyword. ;

; Using or Ignoring Flags ;

; Flags (set via flag) can be selectively ; applied or ignored using the useflag and skipflag keywords. Only one of ; those two keywords can be used at a time (it is an error to use both ; at the same time). Both can be either a boolean (/useflag or /skipflag) ; or an array of strings. The default is /useflag, meaning that all flag ; rules that have been previously set are applied when the data is ; fetched from disk, blanking data as described by each rule. If ; /skipflag is set, then all of the flag rules associated with this data ; are ignored and no data will be blanked when fetched from disk (it ; may still contain blanked values if the actual values in the disk ; file have already been blanked by some other process). If useflag is a ; string or array of strings, then only those flag rules having the ; same idstring value are used to blank the data. If skipflag is a ; string or array of strings, then all flag rules except those ; with the same idstring value are used to blank the data. ;

; Dealing With Duplicate Scan Numbers ;

; There are 3 ways to attempt to resolve ambiguities when the ; same scan number appears in the data source. The instance keyword ; refers to the element of the returned array of scan_info structures ; that scan_info returns. So, if scan 23 ; appears 3 times then instance=1 refers to the second time that scan 23 ; appears as returned by scan_info. The file keyword is useful if a ; scan is unique to a specific file and multiple files have been accessed ; using dirin. If file is specified and instance ; is also specified, then instance refers to the instance of that scan ; just within that file (which may be different from its instance within ; all opened files when dirin is used). The timestamp keyword is another ; way to resolve ambiguous scan numbers. The timestamp here is a string ; used essentially as a label by the monitor and control system and is ; unique to each scan. The format of the timestamp string is ; "YYYY_MM_DD_HH:MM:SS". When timstamp is given, scan and instance ; are ignored. If more than one match is found, an error is ; printed and this procedure will not continue. ; ; @param scan {in}{required}{type=integer} M&C scan number ; @keyword ifnum {in}{optional}{type=integer} IF number ; (starting with 0). Defaults to the lowest value associated with data ; taking into account any user-supplied values for fdnum, and plnum. ; @keyword intnum {in}{optional}{type=integer} Integration ; number (starting with 0), defaults to all integrations. ; @keyword plnum {in}{optional}{type=integer} Polarization number ; (starting with 0). Defaults to the lowest value with data after ; determining the values of ifnum and fdnum if not supplied by the ; user. ; @keyword fdnum {in}{optional}{type=integer} Feed number. Defaults ; to the lowest value with data after determining the value of ifnum ; if not supplied by the user and using any value of plnum supplied by ; the user. ; @keyword sampler {in}{optional}{type=string} sampler name, this is ; an alternative way to specify ifnum,plnum, and fdnum. When sampler ; name is given, ifnum, plnum, and fdnum must not be given. ; @keyword eqweight {in}{optional}{type=boolean} When set, all ; integrations are averaged with equal weight (1.0). Default is unset. ; @keyword tcal {in}{optional}{type=float} Cal temperature (K) to use ; in the Tsys calculation. If not supplied, the mean_tcal value from ; the header of the cal_off switching phase data in each integration ; is used. This must be a scalar, vector tcal is not yet supported. ; The resulting data container will have it's mean_tcal header value ; set to this keyword when it is set by the user. ; @keyword sig_state {in}{optional}{type=integer} For use with ; sig-switched data. If sig_state is 1 then only the signal data are ; used, if sig_state is 0 then only the reference data are used. ; @keyword quiet {in}{optional}{type=boolean} When set, the normal ; status message on successful completion is not printed. This will ; not affect error messages. Default is unset. ; @keyword keepints {in}{optional}{type=boolean} When set, the ; individual integrations are saved to the current output file ; (fileout). This keyword is ignored if a specific integration is requested ; using the intnum keyword. Default is unset. ; @keyword useflag {in}{optional}{type=boolean or string} ; Apply all or just some of the flag rules? Default is set. ; @keyword skipflag {in}{optional}{type=boolean or string}{default=unset} Do not apply ; any or do not apply a few of the flag rules? Default is unset. ; @keyword instance {in}{optional}{type=integer} Which occurrence ; of this scan should be used. Default is 0. ; @keyword file {in}{optional}{type=string} When specified, limit the search ; for this scan (and instance) to this specific file. Default is to ; search all files currently opened. ; @keyword timestamp {in}{optional}{type=string} The M&C timestamp associated ; with the desired scan. When supplied, scan and instance are ; ignored. ; @keyword status {out}{optional}{type=integer} An output parameter to indicate ; whether the procedure finished as expected. A value of 1 means there were ; no problems, a value of -1 means there were problems with the ; arguments before any data was processed, and a value of 0 means that ; some of the individual integrations were processed (and possibly ; saved to the output file if keepints was set) but there was a ; problem with the final average and the contents of buffer 0 likely ; contains just the result from the last integration processed. This ; keyword is primarily of use when using gecal within another ; procedure or function. ; ; @uses accumave ; @uses accumclear ; @uses calsummary ; @uses check_calib_args ; @uses data_free ; @uses dcaccum ; @uses dcscale ; @uses docal ; @uses find_scan_info ; @uses get_calib_data ; @uses set_data_container ; @uses showiftab ; ; @version $Id$ ;- pro getcal,scan,ifnum=ifnum,intnum=intnum,plnum=plnum,fdnum=fdnum,sampler=sampler,eqweight=eqweight, $ tcal=tcal,sig_state=sig_state,quiet=quiet,keepints=keepints,useflag=useflag,$ skipflag=skipflag,instance=instance,file=file,timestamp=timestamp,status=status compile_opt idl2 status = -1 ; basic argument checks argsOK=check_calib_args(scan,ifnum=ifnum,intnum=intnum,plnum=plnum,fdnum=fdnum,sampler=sampler, $ eqweight=eqweight,quiet=quiet,keepints=keepints,useflag=useflag, $ sig_state=sig_state,skipflag=skipflag,instance=instance,file=file,$ timestamp=timestamp,ret=ret,info=info) if not argsOK then return if size(info,/type) ne 8 then return ; This scan must have 1 or CAL states to be used here if info.n_cal_states gt 2 then begin message,string("This does not have 1 or 2 CAL switching states."),/info return endif ; If sig_state selection chosen but there is no sig switching ; then issue warning if ret.sig_state ge 0 and info.n_sig_states ne 2 then begin message,"sig_state argument can only be used for data where the sigref state changes (e.g. frequency switching)",/info endif ; Get the requested data data = get_calib_data(info, ret.ifnum, ret.plnum, ret.fdnum, ret.sampler, count, $ intnum=intnum, useflag=useflag, skipflag=skipflag, sig_state=ret.sig_state) if count le 0 then begin message,"No data found, can not continue.",/info return endif ; from this point on, data contains data containers that must be ; freed whenever this routine returns to avoid memory leaks if info.n_cal_states ne 2 then begin message,'getcal requires cal-switching data',/info return endif ; find where CAL is on and where CAL is off sigoff = where(data.cal_state eq 0, countOff) sigon = where(data.cal_state eq 1, countOn) ; Final sanity checks ; In this calibration, we calibrate each integration separately ; and then average the results. That means that we need the ; same number of cal on as cal off values. if (countOff ne countOn) then begin message,'Number of spectra with CAL off is not the same as the number with CAL on, can not continue',/info data_free, data return endif ; And finally, there should be one spectra per sig state per ; integration for each cal state if n_elements(intnum) eq 1 then begin nIntegrations = 1 endif else begin ; find appropriate value for this sampler sampIndx = (where(info.samplers eq data[0].sampler_name))[0] nIntegrations = info.n_sampints[sampIndx] endelse expectedCount = info.n_sig_states * nIntegrations ; if sig selection, expect 1/2 that if ret.sig_state ge 0 then expectedCount = expectedCount / 2 if (countOff ne expectedCount) then begin message,"Unexpected number of spectra retrieved, can not continue.",/info data_free, data return endif status = 0 missing = 0 ; process all integrations, averaging them as they are processed ; keep track of the number of integrations that are not ; included in the average - this happens when the result of ; processing that integration was a spectra where all of the data ; values were blanked. ; if eqweight is not set, then this next line won't set ; the weight value here and hence "weight" in the call ; to dcaccum later on will still be unset, causing ; dcaccum to use it's default weighting. if keyword_set(eqweight) then weight = 1.0 ; else undefined and use default weight thisaccum = {accum_struct} for i = 0,(nIntegrations-1) do begin docal,result,data[sigoff[i]],data[sigon[i]],tcal=tcal dcaccum,thisaccum,result,weight=weight if keyword_set(keepints) then begin ; re-use raw data containers to conserve space ; defer the actual keep until later ; takes 3 steps because of the nature of IDL ; data passing (value vs reference) tmp = data[sigoff[i]] data_copy, result, tmp data[sigoff[i]] = tmp endif endfor if keyword_set(keepints) then begin putchunk, data[sigoff] endif naccum1 = thisaccum.n if naccum1 le 0 then begin ; nothing was actually accumed - all ints must have been blank message,'Result is all blanked - probably all of the data were flagged',/info ; make sure something is put into the PDC ; this can only happen if result is all blanks, use that set_data_container,result ; clean up accumclear, thisaccum data_free, result data_free, data return endif else begin ; get the average accumave,thisaccum, thisave, /quiet missing = naccum1 ne nIntegrations ; put it into the PDC set_data_container, thisave ; cleanup the averager data_free, thisave accumclear, thisaccum status = 1 endelse ; clean up the result temporary data_free, result if not keyword_set(quiet) then begin if missing then nmiss = nIntegrations-naccum1 calsummary,info.scan,!g.s[0].tsys,'',missingInts=nmiss, $ ifnum=ret.ifnum,fdnum=ret.fdnum,plnum=ret.plnum endif ; clean up the data data_free,data end