VLBEDIT


VLBEDIT is used to edit data in MERGE format.   Both  MERGE-formats  1
and  2 are accepted.  It is capable of changing most header parameters
and it can perform a variety of editing operations on the  data.   For
details  on  the operations, see the parameter descriptions below.  To
run VLBEDIT, type the command VLBEDIT (defined in  VLB:LOGIN.COM)  and
answer  the questions.  It will ask for input and output data files, a
single header control record and  up  to  300  data  control  records.
VLBEDIT can be run from a command file by providing the answers to the
questions on successive lines.  This is recommended in order to keep a
record  of  what  editing has been done.  Program IED (q.v.) is highly
recommended for generating such a command file.  The command file  may
be  modified  (with  a  text editor) to incorporate additional editing
instructions.

HEADER CONTROL PARAMETERS

Each parameter provided changes the  corresponding  parameter  in  the
header  to  the new value.  Angle and time parameters are given in the
format  ddd:mm:ss.ss  and  hh:mm:ss.ss.   Character  strings  must  be
enclosed  in  quotation  marks (' or ").  Terminate the header control
parameters with a slash (/).

   RA        RA (1950)
   DEC       Dec (1950)
   RAP       RA (Precessed)
   DECP      Dec (Precessed)
   FLUX      Flux density (Jy)
   NAME(n)   Name of station n, where n is between 1 and 15
   X(n)      X coordinate of station n (m)
   Y(n)      Y coordinate of station n (m)
   Z(n)      Z coordinate of station n (m)
   YEAR      Year
   DAY       Day of the GST provided
   UT        Time (UT) of the GST provided.
   GST       Greenwich sidereal time at UT provided.
   FREQ      Frequency (Hz)
   TINTG     Integration time (sec)
   SOURCE    Source name
   IUNITS    0  if data are correlation coefficient
             1  if data are visibility (in Jy)
             2  if data are fringe rate
   HISTORY   New history record  -  up to 80 characters.

DATA CONTROL PARAMETERS

(Up to 300 groups - / at end of each group.) These parameters  control
editing of data.  Each group must include a "verb" that determines the
action to be taken.  Each group must also specify which data are to be
altered.


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VERBS

     COPY       Copy data - no editing
     DELETE     Delete the data - The data are flagged by making the
                     error negative so other programs won't use them.
     RESTORE    Restore "deleted" data
     KILL       Remove specified records. The record (which includes
                     all data for a particular time) is not copied.
                      The record numbers will be different after this
                      operation.  It is not recommended. Use DELETE.
  
VERBS with argument

     MULTIPLY   Multiply specified data by argument.
     ADD        Add argument to specified data.
     ERRMULT    Multiply errors of specified data by argument.
     ERRADD     Add argument to errors of specified data.

DATA SPECIFICATION:

     ALL        All types subject to the constraints discussed in the
                    section on station names
     AMP        Amplitudes (Fluxes) (units: Jy for calibrated
                    data, or correlation coefficient [max 1.0] for
                    uncalibrated data)
     FLUX       = AMP
     PHASES     Visibility phases (units: degrees)
     CLOSE      Closure phases (units: degrees)

     The default is ALL.  More than one type may be specified.

STATION NAMES:

     Use the station names exactly as they appear in the header
     (Program LIST can provide a listing).  If no station names
     are given, all data are processed.  If one name is given, all
     data involving that station can be processed.  If two names are
     given, the baseline and all closure phases involving the two
     stations can be processed.  If three names are given, the 
     closure phase involving all three stations can be processed.

RECORD NUMBERS

     N        Individual records to be processed.  Up to 100 numbers.
                    (eg.  N=23,34,190,35,354 )
     INT      Ranges of records to be processed. Up to 20 pairs.
                    (eg.  INT=23,45,67,70  means process records 
                    23 through 45 and records 67 through 70) 
     The record number is the line number in LIST output.

EXAMPLES

Header Control 
       1.  DAY = 151  UT 00:00:00. GST 17:35:42.684 /
         Set GST to the specified value at 0 hr on day 151.

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       2.  HISTORY  "DATA PROCESSED WITH BAD GASTM"  /
         Add comment to history records.

Data Control
       1.  DELETE NRAO N 25,36  INT 50,75 /
         Deletes all NRAO data in records 25,36, and 50 through 75.
   
       2.  MULTIPLY  1.25  FDVS  OVRO  AMP  INT 30,48 /
         Multiply the amplitudes on the FDVS to OVRO baseline by 1.25
         for records 30 through 48 /

       3.  KILL  N = 3,4 /
         Do not copy records 3 and 4.


Deficiencies

VLBEDIT can not yet alter station header parameters when  the  station
is an orbiting VLBI observatory (MERGE-format 2, station type 2).  Any
attempt  to  alter  X,  Y,  and  Z  for  such  a  stations  will  have
unpredictable  results.   VLBEDIT  can  alter the visibility data in a
MERGE-format 2 data record but it cannot alter the U, V, and W data in
that record (see VLBHELP FORMAT for a description of MERGE-format 2).


Program History:

Version ???:  1982 Dec 15 (increase to 300 control groups; fix bugs)

Version ???:  1983 Aug  3  (Extend  to  MERGE-format  2  files.   D.L.
Meier.)


                                              R.C. Walker, 1982 Dec 15
                                                   Revised 1984 Oct 11