path: root/noao/astcat/doc/acatpars.hlp

.help acatpars Mar00 astcat
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NAME
acatpars -- edit the default astrometry file format parameters
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USAGE
acatpars 
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PARAMETERS
.ls ftype = "stext"
The astrometry file format. The current options are:
.ls stext
Simple text. Records are newline delimited and fields are whitespace delimited.
.le
.ls btext
Blocked text. Records are newline delimited and fields are offset and
size delimited.
.le
.le
.ls ccsystem = "j2000"
The default celestial coordinate system. The coordinate systems of most
interest to users are "icrs", "j2000", and "b1950". For more detailed
information on all the celestial coordinate system options type
"help ccsystems".
.le
.ls standard astrometry file fields
The following parameters define the standard astrometry file fields. The
parameter names are the same as the standard field names. The parameter
values are the standard field descriptions.
.sp
Every astrometry file returned by
a catalog query or created by the user must contain the standard fields ra and
dec. The remaining fields are optional and may or may not be present
in either the original catalog or the astrometry file produced by a
catalog query.
.sp
The format of the standard fields is "fieldno [units [format]]" for simple
text files and "foffset fsize [units [format]]" for blocked text files
where the quantities in "[]" are optional. Standard fields with "" valued
field descriptions are assumed to be undefined.
.sp
.ls id = ""
The standard id field. The data type is character. The default units and
format values are "INDEF" and "%20s".
.le
.ls  ra = "1 hours"
The standard right ascension / longitude field. The data type is double. The
default units and format values are "hours"and "%11.2h".
.le
.ls  dec = "2 degrees"
The standard declination / latitude field. The data type is double. The default
units and format values are "degrees"and "%11.1h".
.le
.ls  era = ""
The standard right ascension / longitude error field. The data type is double.
The default units and format values are "asecs" and "%6.3f".
.le
.ls  edec = ""
The standard declination / latitude error field. The data type is double.
The default units and format values are "asecs" and "%6.3f".
.le
.ls  pmra = ""
The standard right ascension / longitude proper motion field. The data type
is double. The default units and format values are "masecs/yr" and "%7.3f".
.le
.ls  pmdec = ""
The standard declination / latitude proper motion field. The data type
is double. The default units and format values are "masecs/yr" and "%7.3f".
.le
.ls  epmra = ""
The standard right ascension / longitude proper motion error field. The data
type is double. The default units and format values are "masecs/yr" and "%7.3f".
.le
.ls  epmdec = ""
The standard declination / latitude proper motion error field. The data
type is double. The default units and format values are "masecs/yr" and "%7.3f".
.le
.ls catsystem = ""
The standard celestial coordinate system field. The data type is character.
The default units and format field values are "INDEF" and "%15s". If defined
the value of this field overrides the coordinate system defined by the
\fIcsystem\fR parameter. Supported values of catsystem are "icrs", "fk5",
"fk4", "fk4-noe", "ecliptic", "galactic", and "supergalactic".
.le
.ls equinox = ""
The standard celestial coordinate system equinox field. The data type is
character. The default units and format field values are "INDEF" and
"%15s". Equinoxes are typical expressed as Julian epochs e.g. "J2000.0",
Besselian epochs e.g. "B1950.0", or years "2000.0".
.le
.ls epoch = ""
The standard celestial coordinate system epoch field. The data type is
character. The default units and format field values are "INDEF" and
"%15s". Epochs are typical expressed as Julian epochs e.g. "J2000.0",
Besselian epochs e.g. "B1950.0", years "2000.0", or Julian date if the
epoch value > 3000.0.
.le
.ls px = ""
The standard parallax field. The data type is double. The default units
and format values are "msecs" and "%6.3f".
.le
.ls rv = ""
The standard radial velocity field. The data type is double. The default units
and format values are "km/sec" and "%6.3f".
.le
.ls epx = ""
The standard parallax error field. The data type is double. The default units
and format values are "msecs" and "%6.3f".
.le
.ls erv = ""
The standard radial velocity error field. The data type is double. The default
units and format values are "km/sec" and "%6.3f".
.le
.ls mag = ""
The standard magnitude field. The  data type is real. The default units
and format field values are "mags" and "%8.3f".
.le
.ls color = ""
The standard color field. The  data type is real. The default units
and format field values are "mags" and "%8.3f".
.le
.ls emag = ""
The standard magnitude error field. The  data type is real. The default units
and format field values are "mags" and "%8.3f".
.le
.ls ecolor = ""
The standard color error field. The  data type is real. The default units
and format field values are "mags" and "%8.3f".
.le
.ls xp = ""
The predicted x coordinate field. The data type is double. The default units
and format field values are "pixels" and "%9.3f".
.le
.ls yp = ""
The predicted y coordinate field. The data type is double. The default units
and format field values are "pixels" and "%9.3f".
.le
.ls xc = ""
The centered x coordinate field. The data type is double. The default units
and format field values are "pixels" and "%9.3f".
.le
.ls yc = ""
The centered y coordinate field. The data type is double. The default units
and format field values are "pixels" and "%9.3f".
.le
.ls exc = ""
The centered x coordinate error field. The data type is double. The default
units and format field values are "pixels" and "%9.3f".
.le
.ls eyc = ""
The centered y coordinate error field. The data type is double. The default
units and format field values are "pixels" and "%9.3f".
.le
.ls imag = ""
The standard instrumental magnitude field. The data type is real. The default
units and format values are "mags" and "8.3f".
.le
.ls eimag = ""
The standard instrumental magnitude error field. The data type is real. The
default units and format values are "mags" and "8.3f".
.le
.le

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DESCRIPTION

The acatpars parameters define the default astrometry file format. These
parameters are used if the input astrometry file does not contain a standard
header describing the file format. By default standard headers are written
by all astcat package tasks which create astrometry files. If the
astrometry file does not have a header the acatpars parameters
are used to define one.

By default acatpars assumes that the input astrometry file is a
simple text file, \fIftype\fR = "stext", with newline delimited records
and whitespace delimited fields. In this case users can define
the fields by setting the appropriate standard file parameters
to a string with the following format, e.g.

.nf
parname = "fieldno [units [format]]"

     ra = "1 hours"
    dec = "2 degrees"
.fi

where fieldno is the field or column number in the record. The
units and format strings are optional and reasonable defaults are
supplied if they are missing. Currently the units information is
only used for decoding coordinate fields. For other fields the
units should be left at their default values. The format information
is used when an application has to decode a field into a numeric value
modify it in some way and rewrite it.

If \fIftype\fR is set to "btext" for blocked text the input astrometry file
is assumed to be a text file with newline delimited records and fixed size
fields. This format can be used to describe astrometry files with
fields containing embedded blanks such as id fields. In this case users
define the fields by setting the appropriate standard file parameters to
a string with the following format, e.g.

.nf
parname = "foffset fsize [units [format]]"
     ra = "1 15 hours"
    dec = "16 15 degrees"
.fi

where foffset and fsize are the field offset and size in characters.
Formats and units are treated in the same way as they for simple text files.

The fundamental coordinate system of the astrometry file is set by
the \fIcsystem\fR parameter. This is a global parameter applying to the
entire astrometry file . Its value is overwritten if the "catsystem" standard
field is defined, in which case the astrometry file may contain entries in
many different fundamental coordinate systems.

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EXAMPLES
1. List the astrometry file format parameters.

.nf
cl> lpar acatpars
.fi

2. Edit the astrometry file format parameters.

.nf
cl> acatpars
... edit the parameters in the usual way
... type :wq to quit and save the edits
.fi

3. Edit the astrometry file format parameters from the afiltcat task.

.nf
cl> epar afiltcat
... edit the afiltcat parameters
... move to the acatpars parameter line and type :e
... edit the acatpars parameters
... type :wq to quit and save the acatpars edits
... continue editing the remaining afiltcat parameters
... type :go to execute the task
.fi

4. Save the current acatpars parameter values in a text file called
acat1.par.  Use the saved parameter set in the next call to the afiltcat
task.

.nf
cl> epar acatpars
... edit some parameters in the usual way
... type :w acat1.par
... type :q to quit
cl> afiltcat ... acatpars=afilt1.par ...
.fi

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TIME REQUIREMENTS
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BUGS
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SEE ALSO
afiltcat
.endhelp