Public parameter group NGEN
This document contains an overview of the public parameter group NGEN, (part of) which is included in several NEWSTAR programs.
The document describes the individual parameters in alphabetical order. This description centers on the Help texts, which have been designed to guide the user to the proper choice at each junction, even if his knowledge of the overall workings of the program is only superficial.
Please note that the generic prompt and help texts defined for these parameters are frequently superseded in the actual applications by alternative texts that are more appropriate to the situation at hand. Unfortunately, the present architecture of NEWSTAR precludes the inclusion of such texts in the documentation system, so the only opportunity to read that information is during program execution (in your terminal window!).
Prompt: Specify visibility corrections (may vary per application)
Expected input: Character *8: 1 to 16 values
In general, the uv data in a .SCN file are not physically modified. Instead, correction parameters are stored in the sector and scan headers of the .SCN file, to be applied 'on-the-fly' to the visibilities as they are read into memory to be processed.
You may specify here the corrections to be applied by specifying a combination of possible options (separated by commas). The prefix 'NO' indicates that a correction must not be applied and would most likely be used in combination of ALL.
ALL or * apply all available corrections
NONE or "" apply no corrections
[NO]RED redundancy corrections (telescope gain,phase)
[NO]ALG align corrections (telescope gain,phase)
[NO]OTH other telesc. gain/phase corrns (i.e. from calibrator)
[NO]EXT extinction correction (elevation-dependent gain)
[NO]REF refraction correction (elevation-dependent phase)
[NO]IREF ionospheric refracion
[NO]CLK clock correction
[NO]POL polarisation corrections (dipole angle, ellipticity)
[NO]FAR Faraday rotation
[NO]MIFR multiplicative interferometer errors
NOTES:
1. If two options are mutually exclusive, the one specified last prevails,
e.g.
NONE,CLK,POL selects only the CLK and POL corrections;
CLK,POL,NONE selects no corrections at all.
2. If a certain correction is to be disabled permanently, the safest way is to zero it in the .SCN file itself, using NCALIB option SET ZERO.
This keyword is part of NGEN, i.e. it is a NEWSTAR 'environment keyword', which is available to all NEWSTAR programs. The switch /NOASK indicates that it is 'hidden', i.e. the user is not prompted for it, but the default value is used.
Its value may be modified (for a given $stream) in several ways:
Permanently for all programs and streams during current login:
change the default value: dws[pecify] 'NGEN$0
Permanently for all programs in certain stream during current login:
change the default value: dws[pecify] NGEN['$stream']
Permanently for certain program in all streams during current login:
change the default value: dws[pecify] 'program$0'
Permanently for certain program in certain stream during current login:
change the default value: dws[pecify] program['$stream']
Note: use automatic saving in LOGOUT to pass on values beyond current login
Incidentally for a certain incarnation of program[$stream]:
run as: dwe program['$stream']/APPLY=value (or:
='(val1,val2,...)')
Incidentally for all hidden values:
run a NEWSTAR program as: dwe program['$stream']/ASK
Prompt: default directory name (may vary per application)
Expected input: Character *80: 1 value
Directory names can be very long. In order to avoid having to type them fully each time, the user may store it in the keyword DATAB (the name has historic roots). From then on, node names (in the same $stream) are automatically preceded by the contents of DATAB.
NB: On Unix systems, the value of DATAB has to end with a slash (eg ./)
If you set DATAB to "*", the DATAB keyword will be ignored completely (it will not be changed if you use a directory name in the specification of a set etc.)
NB: In general, however, it is recommended to keep all files of a reduction project in a single directory. In that case, no explicit directory name will be needed in any case, if you run from this directory.
Example: if node name is preceded by a directory name:
../../wnb/wsrt/data/myproject/mynode the value of DATAB (for the
current $stream) will be:
../../wnb/wsrt/data/myproject/ Subsequently, typing 'othernode' will
produce the node name:
../../wnb/wsrt/data/myproject/othernode NB: IF THE NEWSTAR PROGRAM
CANNOT FIND A FILE (NODE), WHILE IT IS CLEARLY PRESENT IN THE CURRENT
DIRECTORY, CHECK THE VALUE OF DATAB!
This keyword is part of NGEN, i.e. it is a NEWSTAR 'environment keyword', which is available to all NEWSTAR programs. The switch /NOASK indicates that it is 'hidden', i.e. the user is not prompted for it, but the default value is used.
Its value may be modified (for a given $stream) in several ways:
Permanently for all programs and streams during current login:
change the default value: dws[pecify] 'NGEN$0'
Permanently for all programs in certain stream during current login:
change the default value: dws[pecify] NGEN['$stream']
Permanently for certain program in all streams during current login:
change the default value: dws[pecify] 'program$0'
Permanently for certain program in certain stream during current login:
change the default value: dws[pecify] program['$stream']
Note: use automatic saving in LOGOUT to pass on values beyond current login
Incidentally for a certain incarnation of program[$stream]:
run as: dwe program['$stream']/DATAB='"value"'
Incidentally for all hidden values:
run a NEWSTAR program as: dwe program['$stream']/ASK
Prompt: Delete node (YES/NO)? (may vary per application)
Expected input: Yes/No: 1 value
Specify the deletion of a node (YES) or not (NO)
Prompt: Specify visibility de-corrections (may vary per application)
Expected input: Character *8: 1 to 16 values
In general, the visibilties in a .SCN file are not physically modified. Instead, correction parameters are stored in the sector and scan headers of the
memory to be processed.
It is also possible, however, to make corrections more permanent by applying them to the visibilities as stored in the .SCN file. The pertinent correction parameters are reset to 0 in this process and their values transferred into a second set of correction parameters, the "applied" corrections. Thus, for each correction parameter <xxx> there is an 'applied' counterpart A<xxx>.
Just like it is possible to apply corrections on-the-fly, it is also possible to 'de-apply' the 'applied' corrections on-the-fly. You may specify here which 'applied' corrections you want to de-apply in this way.
The prefix 'NO' indicates that a correction must not be applied and would most likely be used in combination of ALL.
ALL or * apply all available corrections
NONE or "" apply no corrections
[NO]RED redundancy corrections (telescope gain,phase)
[NO]ALG align corrections (telescope gain,phase)
[NO]OTH other telesc. gain/phase corrns (i.e. from calibrator)
[NO]EXT extinction correction (elevation-dependent gain)
[NO]REF refraction correction (elevation-dependent phase)
[NO]IREF ionospheric refracion
[NO]CLK clock correction
[NO]POL polarisation corrections (dipole angle, ellipticity)
[NO]FAR Faraday rotation
[NO]MIFR multiplicative interferometer errors
[NO]SHFT shift of centre of observations
[NO]MOD subtract model
NOTES:
1. If two options are mutually exclusive, the one specified last prevails,
e.g.
NONE,CLK,POL selects only the CLK and POL corrections;
CLK,POL,NONE selects no corrections at all.
2. The only DE_APPLY correction type that is ever different from zero so far is MODEL. This type controls the subtraction of a source model strored internally in .SCN-file sector.
This keyword is part of NGEN, i.e. it is a NEWSTAR 'environment keyword', which is available to all NEWSTAR programs. The switch /NOASK indicates that it is 'hidden', i.e. the user is not prompted for it, but the default value is used.
Its value may be modified (for a given $stream) in several ways:
Permanently for all programs and streams during current login:
change the default value: dws[pecify] 'NGEN$0'
Permanently for all programs in certain stream during current login:
change the default value: dws[pecify] NGEN['$stream']
Permanently for certain program in all streams during current login:
change the default value: dws[pecify] 'program$0'
Permanently for certain program in certain stream during current login:
change the default value: dws[pecify] program['$stream']
Note: use automatic saving in LOGOUT to pass on values beyond current login
Incidentally for a certain incarnation of program[$stream]:
run as: dwe program['$stream']/DE_AP=value (or:
'(val1,val2,...)')
Incidentally for all hidden values:
run a NEWSTAR program as: dwe program['$stream']/ASK
Prompt: Output Display (may vary per application)
Expected input: Character *24: 1 value
Specify the X-Display on which to produce output. E.g. if you are working from a workstation or Xterminal called e.g. rzmwx5 on another machine (maybe a fast processor, say rzmvfp); you can get the NGIDS display on your local machine by giving as answer: rzmwx5:0.0
If you specify a wildcard (*) or an empty answer, the display will be taken from the environment variable DISPLAY; if this environment variable does not exist, the default :0.0 will be assumed.
If your display machine is your working machine, give :0.0 (the default).
Note: Before being able to use your local display you should enable it by
typing while logged in on your local machine (rzmwx5) either:
xhost + or:
xhost +rzmfvp
Prompt: node name shorthand (may vary per application)
Expected input: Character *80: 1 value
NEWSTAR file names can be very long. In order to avoid having to type them fully each time, the user may store (part of) the node name in the keyword INFIX. From then on, the user may specify node names in a short-hand notation which contains a hash (#) character. The latter is automatically replaced by the contents of INFIX, to produce the full file name.
Example: if part of the full node name is enclosed in brackets:
mynode.21(cm.yesterday.s.x.c.d.file.d)d the value of INFIX (for the
current $stream) will be:
cm.yesterday.s.x.c.d.file.d Subsequently, typing '92#e' will produce
the node name:
mynode.92cm.yesterday.s.x.c.d.file.de
This keyword is part of NGEN, i.e. it is a NEWSTAR 'environment keyword', which is available to all NEWSTAR programs. The switch /NOASK indicates that it is 'hidden', i.e. the user is not prompted for it, but the default value is used.
Its value may be modified (for a given $stream) in several ways:
Permanently for all programs and streams during current login:
change the default value: dws[pecify] 'NGEN$0'
Permanently for all programs in certain stream during current login:
change the default value: dws[pecify] NGEN['$stream']
Permanently for certain program in all streams during current login:
change the default value: dws[pecify] 'program$0'
Permanently for certain program in certain stream during current login:
change the default value: dws[pecify] program['$stream']
Note: use automatic saving in LOGOUT to pass on values beyond current login
Incidentally for a certain incarnation of program[$stream]:
run as: dwe program['$stream']/INFIX=value
Incidentally for all hidden values:
run a NEWSTAR program as: dwe program['$stream']/ASK
Prompt: log-file disposition (may vary per application)
Expected input: Character *8: 1 value
For each run of a NEWSTAR program, logging information may be put into a LOG-file, for subsequent inspection (and clogging up your room). LOG-files are named with the first three letters of the program name (e.g. NCA), followed by yymmddhhmmssA.LOG in the current working directory. E.g. NCA940305163412A.LOG The most recent LOG-file for a program has an alias name equal to the program, and the extension .LOG (e.g. NCALIB.LOG).
The LOG-file contains the values for all the parameter (keywords) that were used for this particualr program run, including the 'hidden' ones. It will also contain information about the program run itself, and any results.
Specify what to do with the logging output:
NO: Make no LOG-file (not recommended)
YES: Make a LOG-file (preferred option, no line-printer output)
SPOOL: Print the LOG-file on the printer at the end of the program run
CATEN: Add the new info to the existing LOG-file for this program
This keyword is part of NGEN, i.e. it is a NEWSTAR 'environment keyword', which
is available to all NEWSTAR programs. The switch /NOASK indicates that it is
'hidden', i.e. the user is not prompted for it, but the default value is used.
Its value may be modified (for a given $stream) in several ways:
Permanently for all programs and streams during current login:
change the default value: dws[pecify] 'NGEN$0'
Permanently for all programs in certain stream during current login:
change the default value: dws[pecify] NGEN['$stream']
Permanently for certain program in all streams during current login:
change the default value: dws[pecify] 'program$0'
Permanently for certain program in certain stream during current login:
change the default value: dws[pecify] program['$stream'] Note:
use automatic saving in LOGOUT to pass on values beyond current login
Incidentally for a certain incarnation of program[$stream]:
run as: dwe program['$stream']/LOG=value
Incidentally for all hidden values:
run a NEWSTAR program as: dwe program['$stream']/ASK
Prompt: Specify memory units (may vary per application)
Expected input: Integer: 1 value
Specify the amount of memory to be used per buffer for some applications. These applications could run faster in some instances by increasing (if a lot of physical memory present) or lowering (if a lot of swapping) this Value.
This keyword is part of NGEN, i.e. it is a NEWSTAR 'environment keyword', which
is available to all NEWSTAR programs. The switch /NOASK indicates that it is
'hidden', i.e. the user is not prompted for it, but the default value is used.
Its value may be modified (for a given $stream) in several ways:
Permanently for all programs and streams during current login:
change the default value: dws[pecify] 'NGEN$0'
Permanently for all programs in certain stream during current login:
change the default value: dws[pecify] NGEN['$stream']
Permanently for certain program in all streams during current login:
change the default value: dws[pecify] 'program$0'
Permanently for certain program in certain stream during current login:
change the default value: dws[pecify] program['$stream'] Note:
use automatic saving in LOGOUT to pass on values beyond current login
Incidentally for a certain incarnation of program[$stream]:
run as: dwe program['$stream']/MEM=value
Incidentally for all hidden values:
run a NEWSTAR program as: dwe program['$stream']/ASK
Prompt: default directory for model files (may vary per application)
Expected input: Character *80: 1 value
For calibrator sources one usually want to use a generic model, and it is good practice to collect such models in a single directory.
Newstar programs look for a calibrator model first in your 'preferred' directory, then in the directory defined by MODELB, and finally in the directory defined by the Unix environmant variable MODELB. The latter points to the standard WSRT calibrator models that are part of Newstar. NOTE: On Unix systems, the value of MODELB has to end with a slash (eg ./)
This keyword is part of NGEN, i.e. it is a NEWSTAR 'environment keyword', which is available to all NEWSTAR programs. The switch /NOASK indicates that it is 'hidden', i.e. the user is not prompted for it, but the default value is used.
Its value may be modified (for a given $stream) in several ways:
Permanently for all programs and streams during current login:
change the default value: dws[pecify] 'NGEN$0'
Permanently for all programs in certain stream during current login:
change the default value: dws[pecify] NGEN['$stream']
Permanently for certain program in all streams during current login:
change the default value: dws[pecify] 'program$0'
Permanently for certain program in certain stream during current login:
change the default value: dws[pecify] program['$stream']
Note: use automatic saving in LOGOUT to pass on values beyond current login
Incidentally for a certain incarnation of program[$stream]:
run as: dwe program['$stream']/MODELB='"value"'
Incidentally for all hidden values:
run a NEWSTAR program as: dwe program['$stream']/ASK
Prompt: Exectute program after parameter setup (YES/NO)? (may vary per application)
Expected input: Yes/No: 1 value
Specify the run mode of the NEWSTAR program:
YES: The NEWSTAR program will run normally
NO: The NEWSTAR program will prompt the user for all parameters
(keywords), but will then terminate. This mode should be used in conjunction
with the '/save' option, in which all the specified keyword values will be
saved in a .SAV file for later use (e.g. batch processing).
The /save option is invoked by starting the program in the following way:
dwe 'program'[$'stream']/save (e.g. dwe ncalib$3/save). The saved
keyword values are used by running the program again:
dwe 'program'[$'stream'] (e.g. dwe ncalib$3)
NB: An alternative approach is to use the '/norun' option:
dwe 'program'[$'stream']/norun (e.g. dwe ncalib'$3'/norun)
This keyword is part of NGEN, i.e. it is a NEWSTAR 'environment keyword', which is available to all NEWSTAR programs. The switch /NOASK indicates that it is 'hidden', i.e. the user is not prompted for it, but the default value is used.
Its value may be modified (for a given $stream) in several ways:
Permanently for all programs and streams during current login:
change the default value: dws[pecify] 'NGEN$0'
Permanently for all programs in certain stream during current login:
change the default value: dws[pecify] NGEN['$stream']
Permanently for certain program in all streams during current login:
change the default value: dws[pecify] 'program$0'
Permanently for certain program in certain stream during current login:
change the default value: dws[pecify] program['$stream']
Note: use automatic saving in LOGOUT to pass on values beyond current login
Incidentally for a certain incarnation of program[$stream]:
run as: dwe program['$stream']/ASK=value
Incidentally for all hidden values:
run a NEWSTAR program as: dwe program['$stream']/ASK
Prompt: Specify which flags you want to ignore | (may vary per application)
Expected input: Character *8: 1 to 16 values
Scan headers and data in a .SCN file can be flagged as invalid. There are 8 different flags distinguishing 8 different types of reasons for the flagging. Flags can be set in a variety of ways, mostly through various options in NFLAG, or by manual flagging in NGIDS.
By default, data points that have any one of the 8 flags set will be discarded. You are given here the option to ignore specific types of flag, i.e. accept data as valid even they have flags of these types set. You may give any combination of options, separated by commas.
NONE or "" ignore none of the flags, i.e. discard all flagged data
ALL or * ignore all flags, i.e. accept all data
MAN ignore MANUAL flags
CLIP ignore CLIP flags
NOIS ignore NOISE flags
SHAD ignore SHADOW flags
ADD ignore ADDITIVE flags
U1 ignore USER1 flags
U2 ignore USER2 flags
U3 ignore USER3 flags NOTES:
1. If two options are mutually exclusive, the one specified last prevails,
e.g.
NONE,CLIP,MAN ignores the CLIP and MAN flags;
CLIP,MAN,NONE iognores none of the flags.
This keyword is part of NGEN, i.e. it is a NEWSTAR 'environment keyword', which is available to all NEWSTAR programs. The switch /NOASK indicates that it is 'hidden', i.e. the user is not prompted for it, but the default value is used.
Its value may be modified (for a given $stream) in several ways:
Permanently for all programs and streams during current login:
change the default value: dws[pecify] 'NGEN$0'
Permanently for all programs in certain stream during current login:
change the default value: dws[pecify] NGEN['$stream']
Permanently for certain program in all streams during current login:
change the default value: dws[pecify] 'program$0'
Permanently for certain program in certain stream during current login:
change the default value: dws[pecify] program['$stream'] .Note:
use automatic saving in LOGOUT to pass on values beyond current login
Incidentally for a certain incarnation of program[$stream]:
run as: dwe program['$stream']/UFL=value (or:
'(val1,val2,...)')
Incidentally for all hidden values:
run a NEWSTAR program as: dwe program['$stream']/ASK
Prompt: | (may vary per application)
Expected input: Character *8: 1 to 16 values
Expected input: Character *80: 1 value
Prompt: | (may vary per application)
Expected input: Character *8: 1 to 16 values
Expected input: Character *80: 1 value
Expected input: Character *8: 1 value
Expected input: Integer: 1 value
Expected input: Character *80: 1 value
Expected input: Yes/No: 1 value
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