CATFRAME = LITERAL (Read)
A string
determining the co-ordinate Frame in which positions are to be stored in the output
catalogue associated with Parameter OUTCAT. The string supplied for CATFRAME can be one
of the following options.
-
A domain name such as SKY, AXIS, PIXEL.
-
An integer value giving the index of the required Frame.
-
An IRAS90 Sky Co-ordinate System (SCS) values such as "EQUAT(J2000)" (see SUN/163).
If a null (!) value is supplied, the positions will be stored in the current Frame. [!]
CATEPOCH = _DOUBLE (Read)
The epoch at which the sky positions stored in the output
catalogue were determined. It will only be accessed if an epoch value is needed to
qualify the co-ordinate Frame specified by COLFRAME. If required, it should be
given as a decimal years value, with or without decimal places ("1996.8" for
example). Such values are interpreted as a Besselian epoch if less than 1984.0
and as a Julian epoch otherwise.
DESCRIBE = _LOGICAL (Read)
If TRUE, a
detailed description of the co-ordinate Frame in which positions are required
will be displayed before the positions are obtained using either Parameter
POSITION or FILE. [current value]
DIM = _INTEGER (Read)
The number of
axes for each position. It is only accessed if a null value is supplied for
Parameter NDF.
EPOCH = _DOUBLE (Read)
If an IRAS90 Sky Co-ordinate System
specification is supplied (using Parameter DOMAIN) for a celestial co-ordinate system,
then an epoch value is needed to qualify it. This is the epoch at which the
supplied sky positions were determined. It should be given as a decimal years
value, with or without decimal places ("1996.8" for example). Such values are
interpreted as a Besselian epoch if less than 1984.0 and as a Julian epoch
otherwise.
FILE = FILENAME (Read)
A text file containing the positions to be
stored in the output positions list. Each line should contain the
formatted axis
values for a single position, separated by white space. It is only accessed if
Parameter MODE is given the value
"File".
FRAME = LITERAL (Read)
Specifies the
co-ordinate Frame of the positions supplied through Parameters POSITION or FILE.
There is a cascade of allowed interpretations of this parameter value; the
search for the co-ordinate Frame ends once there is a successful interpretation,
otherwise the search moves on to the next possible meaning in the following
order.
-
(1)
- An HDS path containing a WCS FrameSet, whose current Frame defines the
co-ordinate Frame.
-
(2)
- The name of an NDF, whose current WCS co-ordinate Frame is used.
-
(3)
- If the parameter value ends with
.FIT, an attempt is made to interpret the
parameter value as the name of a FITS file. If successful, the primary WCS
co-ordinate system from the primary HDU headers is used.
-
(4)
- A text file containing either an AST Frame dump (such as produced by
commands in the ATOOLS package), or a set of FITS WCS headers.
-
(5)
- An IRAS90 Sky Co-ordinate System (SCS) string such as
"EQUAT(J2000)" (see
SUN/163), whereupon the positions are assumed to be two-dimensional
celestial co-ordinates in the specified system.
-
(6)
- Domain name without any interpretation. Any Domain name may be supplied,
but normally one of the standard Domain names, such as GRID, PIXEL,
GRAPHICS should be given. Parameter DIM is used to determine the number of
axes in the Frame.
This parameter is only accessed if the parameter NDF is given a null value.
INCAT =
FILENAME (Read)
A catalogue containing an existing positions list which is to be
included at the start of the output positions list. These positions are mapped into the
current co-ordinate Frame of the supplied NDF, or into the Frame specified by Parameter
FRAME if no NDF was supplied. A message is displayed indicating the Frame in which
alignment occurred. They are then stored in the output list before any further
positions are added. A null value may be supplied if there is no input positions list.
[!]
The mode by which the positions are to be obtained. The
options are as follows.
-
"Interface" –- The positions are obtained using Parameter POSITION.
-
"File" –- The positions are to be read from a text file specified using Parameter
FILE.
-
"Good" –- The positions used are the pixel centres in the data file specified by
Parameter NDF. Only the pixels that have good values in the Data array of the NDF are
used.
-
"Pixel" –- The positions used are the pixel centres in the data file specified
by Parameter NDF. All pixel are used, whether the pixel values are good or
not.
["Interface"]
NDF = NDF (READ)
The NDF which defines the available co-ordinate
Frames in the output positions list. If an NDF is supplied, the positions obtained
using Parameter POSITION or FILE are assumed to be in the current co-ordinate Frame of
the NDF, and the
WCS component of the NDF is copied to the output positions list. If a
null value is supplied, the single co-ordinate Frame defined by Parameter FRAME is
stored in the output positions list, and supplied positions are assumed to be in the
same Frame.
[!] OUTCAT = FILENAME (Write)
The catalogue holding the output
positions list.
POSITION = LITERAL (Read)
The co-ordinates of a single position to
be stored in the output positions list. Supplying
":" will display details of the
co-ordinate Frame in which the position is required. The position should be given as
a list of
formatted axis values separated by white space. You are prompted
for new values for this parameter until a null value is entered. It is only
accessed if Parameter MODE is given the value
"Interface".
TITLE = LITERAL
(Read)
A title for the output positions list. If a null (!) value is supplied,
the value used is obtained from the input positions list if one is supplied.
Otherwise, it is obtained from the NDF if one is supplied. Otherwise, it is
"Output from LISTMAKE". [!]