Creates a catalogue holding a positions list
If an NDF is specified using Parameter NDF, then the positions should be given in the current co-ordinate Frame of the NDF. Information describing the co-ordinate Frames available within the NDF will be copied to the output positions list. Subsequent applications can use this information in order to align the positions with other data sets.
If no NDF is specified, then the user must indicate the co-ordinate Frame in which the positions will be supplied using Parameter FRAME. A description of this Frame will be written to the output positions list for use by subsequent applications.
The positions themselves may be supplied within a text file, or may be given in response to repeated prompts for a parameter. Alternatively, pixel centres in the NDF supplied for Parameter NDF can be used (see Parameter MODE).
The output can be initialised by copying positions from an existing positions list. Any positions supplied directly by the user are then appended to the end of this initial list (see Parameter INCAT).
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. [!]
"1996.8"
for
example). Such values are interpreted as a Besselian epoch if less than 1984.0
and as a Julian epoch otherwise. 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]
"1996.8"
for example). Such values are
interpreted as a Besselian epoch if less than 1984.0 and as a Julian epoch
otherwise. "File"
. .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.
"EQUAT(J2000)"
(see
SUN/163), whereupon the positions are assumed to be two-dimensional
celestial co-ordinates in the specified system.
This parameter is only accessed if the parameter NDF is given a null value.
[!]
"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"]
[!]
":"
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"
. !
) 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"
. [!]
newlist.FIT
containing a list
of positions, together with a description of a single two-dimensional pixel
co-ordinate Frame. The positions are supplied as a set of space-separated pixel
co-ordinates in response to repeated prompts for the Parameter POSITION. stars.txt
containing a list of positions, together with a description of a single
FK4 equatorial RA/DEC co-ordinate Frame (referenced to the B1950 equinox).
The catalogue is stored in a text file using the CAT Small Text List format
("STL"
–-see SUN/190). The positions were determined at epoch B1962.3. The epoch of
observation is required since the underlying model on which the FK4 system is
based is non-inertial and rotates slowly with time, introducing fictitious
proper motions. The positions are supplied hours and degrees values in reponse
to repeated prompts for Parameter POSITIONS. outlist.FIT
containing a list of positions, together with descriptions of all the co-ordinate
Frames contained in the NDF allsky. The positions are supplied as co-ordinates
within the current co-ordinate Frame of the NDF. Application WCSFRAME can be
used to find out what this Frame is. The positions are supplied in a text file
called stars
. out.txt
containing a list
of positions, together with a description of a single galactic co-ordinate
Frame. The positions contained in the existing binary FITS catalogue old.fit
are mapped into galactic co-ordinates (if possible) and stored in the output
positions list. Further galactic co-ordinate positions are then obtained by
repeated prompting for the Parameter POSITION. These positions are appended to
the positions obtained from file old.fit
. old.fit
are mapped into the current
co-ordinate Frame of the NDF (if possible) before being stored in the output
positions list. The new positions must also be supplied in the same Frame (using
Parameter POSITION). profpos.fit
containing the positions of all the pixel
centres in the one-dimensional NDF called prof. This could for instance be
used as input to application PROFILE in order to produce another profile in
which the samples are at the same positions as those in NDF prof. This application uses the conventions of the Cursa package for determining the formats
of input and output catalogues. If a file type of .fit is given, then the catalogue is
assumed to be a FITS binary table. If a file type of .txt is given, then the catalogue
is assumed to be stored in a text file in STL format. If no file type is given, then
".fit"
is assumed.
There is a limit of 200 on the number of positions which can be given using Parameter POSITION. There is no limit on the number of positions which can be given using Parameter FILE.
Position identifiers are asigned to the supplied positions in the order in which
they are supplied. If no input positions list is given using Parameter INCAT,
then the first supplied position will be assigned the identifier "1"
. If an
input positions list is given, then the first supplied position is assigned an
identifier one greater than the largest identifier in the input positions list.