NAME

sgscind -- Find fields in the guide star catalog.

USAGE

sgscind ra dec width

DESCRIPTION

This task searches the guide star catalog index to find any guide star regions that overlap a user-defined field. Fields are defined as a range of coordinates and are specified by the task parameters rahlow through decshi.

Before you can use any of the gasp tasks that access the CD-ROM, you must tell gasp where the CD-ROM is located; this is done by specifying a mount point consisting of a path name and, optionally, a node name if using IRAF networking to a remote host. The two parameters that make up the the mount point are cdrom_north and cdrom_south. If the disks are not mounted on the local host they may be accessible via the IRAF networking capability. To use IRAF networking to access a remotely mounted CD-ROM, prepend the remote host name followed by an exclamation point. This is explained in the parameter descriptions below for cdrom_north and cdrom_south.

The catalog index consists of a list of boundaries of every region in the Guide Star Catalog. This task produces a list containing pathnames of any files on the CD-ROM that correspond to the selected guide star regions. This text is suitable as input to the cdrom task and is printed to STDOUT so that it can be piped to another task.

The sgscind task will also write an ASCII list file containing only the root names of the selected table files. This list may be used as input to the extgst task, which extracts stars from the tables.

Note that this task is called by other tasks in the gasp package and contains the only reference to the Guide Star Catalog CD-ROM location.

PARAMETERS

ra [real, min = 0, max = 24]

Right ascension of the field center (in hours).

dec [real, min = -90, max = 90]

Declination of the field center (in degrees).

width [real, min = 0, max = 180]

Field width (in degrees).

index = "scidata$index" [file name]

Name of the guide star catalog index table.

cdrom_north = "/data/gsc1" [string]

The path name to the mount point for the first volume of the Guide Star Catalog CD-ROM containing the Northern Hemisphere data. Note that this may contain a node name followed by an exclamation point if the disk is mounted on a host accessible via IRAF networking. For example, if the disk is available from host "tib":

	cdrom_north = tib!/data/gsc1

cdrom_south = "/data/gsc2" [string]

The path name to the mount point for the second volume of the Guide Star Catalog CD-ROM containing the Southern Hemisphere data. Note that this may contain a node name followed by an exclamation point if the disk is mounted on a host accessible via IRAF networking. For example, if the disk is available from host "tib":

	cdrom_south = tib!/data/gsc2

region = "REG_NO" [string]

Name of the column containing region number.

rahlow = "RA_H_LOW" [string]

Column name containing the lower limit of right ascension hours.

ramlow = "RA_M_LOW" [string]

Column name containing the lower limit of right ascension minutes.

raslow = "RA_S_LOW" [string]

Column name containing the lower limit of right ascension seconds.

rahhi = "RA_H_HI" [string]

Column name containing the upper limit of right ascension hours.

ramhi = "RA_M_HI" [string]

Column name containing the upper limit of right ascension minutes.

rashi = "RA_S_HI" [string]

Column name containing the upper limit of right ascension seconds.

decsilow = "DECSI_LO" [string]

Column name containing the lower limit of declination sign.

decdlow = "DEC_D_LO" [string]

Column name containing the lower limit of declination degrees.

decmlow = "DEC_M_LO" [string]

Column name containing the lower limit of declination minutes.

decslow = "DEC_S_LO" [string]

Column name containing the lower limit of declination seconds.

decsihi = "DECSI_HI" [string]

Column name containing the upper limit of declination sign.

decdhi = "DEC_D_HI" [string]

Column name containing the upper limit of declination degrees.

decmhi = "DEC_M_HI" [string]

Column name containing the upper limit of declination minutes.

decshi = "DEC_S_HI" [string]

Column name containing the upper limit of declination seconds.

(tablist = "tblist") [string]

List of tables overlapping the field. This is an output parameter.

(nregions = 0) [integer]

Number of regions found (this is an output parameter).

EXAMPLES

BUGS

SEE ALSO

extgst, regions, targets