v3.0  adds the capability of analyzing DCR continuum data processed through SDFITS
      it is a work in progress

      june 2004  t.m. bania
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the following routines have been modified from v2.0:
.....................................................

xxxSHOW  ... now accomodates both LINE and CONTINUUM data.  toggle via LINE/CONT

xxxATTACH    now accomodates a batch ability, i.e. ATTACH,unit,file_name syntax is
          now supported

xxxDEF_XAXIS now supports continuum x-axes

LIST  now tests for EOF.  but this doesn't seem to work... and it CANNOT because
      tmb does not truly understand the ASSOCIATE functions ability to sense an
      EOF.  if it indeed can do so....

GG  attempting to make it work on continuum data

.....................................................
the following  new routines have been written:
.....................................................

xxxLINE  toggle to LINE data reduction and LINE graphics window

xxxCONT  toggle to CONTINUUM data reduction and CONT graphics window

xxxCGBT_WIN  define a continuum graphics window

xxxAZXX   toggle x-axis to Azimuth

xxxELXX   toggle x-axis to Elevation

xxxRAXX   toggle x-axis to Right Ascension

xxxDECX   toggle x-axis to Declination

xxxPLTCHDR  write continuum header to graphics screen during SHOW

xxxMAKE_CDATA  read SDFITS file and write a {gbt_data} output file

xxxSD2CGBT  at the record level, convert the SDFITS header into 
            a {gbt_data} header
  
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these procedures are outside the package proper.  SDFITS writes a record for EACH DCR continuum
data value (!) i guess because each value normally is associated with a new, different position
on the sky during a continuum scan.  nowhere does one at present have any information about the
nature of the data stream.  the procedures below use things that change such as scan number,
polarization, proseqn, etc. to parse the SDFITS data file and deduce the number of data points
per continuum record.  this changes.  focus scans are different than peak scans, etc. 

XXX MAKE_CONT precursor program to MAKE_CDATA

xxxCONTINFO    scan SDFITS continuum data file and determine the # continuum data points
              per record

xxxKONDAR is a batch file (@kondar) which reads the SDFITS file and puts the first 4096 data
       points into !b[0].data.  this is the first thing to do when trying to figure out
       the structure of the SDFITS file 

CONDAR  
===============================================================================================


*** Have modified {gbt_data} structure to contain all SDFITS v1.1 variables passed 
    for avg.acs mode.  Header part of {gbt_data} is now 1024 bytes long with a
    much larger gbt_data.history variable (552 bytes).  This should be sufficient
    to contain all future SDFITS modifications.  Goal is to keep the {gbt_data}
    structure *size* constant for all future 3He data.

*** Following new routines are included:

 xxxIDCHANxxx    takes xaxis value and returns channel number of !xx array 
                 element whose value is closest.  i.e. finds channel number
                 associated with an x-axis value in one of the valid x_axis
                 co-ordinate systems.
              

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Still missing from the package:

ALIGN

WRAP,x_offset  there is an IDL command that can be adapted for this

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  the following has been done during the June 2004 GBT initial 3He run

  these changes together comprise v3.1

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The following commands have been added:

xxxBIASxxx
xxxCGG                    <-- not fully debugged so not part of package
xxxGET_SCANxxx
xxxGGGxxx
xxxLASTXxxx
xxxLASTYxxx
xxxLASTXYxxx
xxxLOOKAVxxx
xxxQAVxxx
xxxQLOOKxxx
xxxQLOOK4xxx
xxxRADIOM
xxxSETRANGExxx
xxxTH_RMS
xxxWRESETxxx
xxxXXxxx
xxxQQQxxx

June 2004 correlator configuration flag commands 

                      'rx1': he3   <-- identical as before
                      'rx2': a91
                      'rx3': b115
                      'rx4': a92
                      'rx5': he3
                      'rx6': hepp
                      'rx7': g131
                      'rx8': g132
 

SMO and SMOOTH had major bugs.  these have been fixed.


../v3.1/DOCS/  contains procedures to make .html help files for the
GBT_IDL package and the libraries that it uses.  See ..v3.1/DOCS/INSTALL_v3.1
for details.