AIPS HELP file for STFND in 31DEC24
As of Fri Apr 26 20:24:00 2024
STFND: Task to find stars in an image and generate an ST table.
INPUTS
INNAME Image name(name).
INCLASS Image name(class).
INSEQ 0.0 9999.0 Image name(seq. #). 0=>high
INDISK Disk drive #. 0=>any
OUTVERS 0.0 46655.0 STar file version number.
BLC Bottem Left pixel of Region
TRC Top Right pixel of Region
CPARM 1: Threshold brightness
2: Max distance to merge
3,4: Min, Max Star Area
5,6: Star size scale
7: Star size constant (asec)
8: Star type to create
9: Maximum number of stars
10: >0 => Return star Ra, Dec
HELP SECTION
STFND
Type: Task
Use: STFND reads through an image and finds objects which are
above a threshold value and cover a user specified number
of pixels. Creates an ST table which can be used for
plotting. (or viewed with PRTAB)
Adverbs:
INNAME......Image name (name). Standard defaults.
INCLASS.....Image name (class). Standard defaults.
INSEQ.......Image name (seq. #). 0 => highest.
INDISK......Disk unit #. 0 => any.
OUTVERS.....Version number of ST (star position) file to be
created. 0 => highest+1.
BLC.........Bottom right corner in input image of desired
subimage. Default is entire image.
TRC.........Top right corner in input image of desired
subimage. Default is entire image.
CPARM.......User specified array 1: Threshold brightness
2: Max distance to merge
3,4: Min, Max Star Area
5,6: Star size scale
7: Star size constant (asec)
8: Star type to create
9: Maximum number of stars
10: >-1 => Return star Ra, Dec
See explain for details.
EXPLAIN SECTION
STFND: Task to find stars in an image and create an ST table.
RELATED PROGRAMS: STARS, CNTR, PCNTR, GREYS, PRTAB
PURPOSE
STFND reads through an image and finds objects which are
brighter than an input limit and cover a specified range of
pixels. The star (ST) Table can optionally contain the
RA DEC and angular size of the star or the pixel number and
total number of counts cooresponding to the star. The ST
table can be view with PRTAB and handled by all the standard
table editting tasks.
COMMENTS
The AIPS adverb CPARM contains the various options for
detecting stars.
CPARM(1) The minimum brightness to be used for a star
detection. (default is 95 percent of map peak)
CPARM(2) Maximum distance to merge objects (1 = objects must
be adjacent to be merged. 2 = objects will be
merged if separated by 1 (low) pixel, etc
CPARM(3) Minimum area (in pixels) a star must cover to be
considered a detection.
CPARM(4) Maximum area (in pixels) a star must cover to be
considered a detection. Set this parameter to
exclude galaxies and/or pairs of stars.
CPARM(5-7)Star size scale. The star is symetric in RA+Dec,
and the star size is a function of the
square root of the area the star covers and the
sum of all pixels composing the star. ie:
Size = CPARM(5)*sqrt(area) + CPARM(6)*total_sum
+ CPARM(7)
Note that CPARM(7) is in arc seconds.
CPARM(8) Type of Star mark to put in the ST table. There are
24 different types of star marks.
1: Plus sign (default) 12: Five pointed star
2: Cross (X) 13: Star of David
3: Circle 14: Seven-pointed star
4: Box 15: Eight-pointed star
5: Triangle 16: Nine-pointed star
6: Diamond 17: Ten-pointed star
7: Pentagon 18: 11-pointed star
8: Hexagon 19: 12-pointed star
9: Septagon 20: 13-pointed star
10: Octagon 21: 14-pointed star
11: Nine-gon 22: Plus with gap
23: Vertical line
24: Cross (X) with gap
CPARM(9) Maximum number of stars to create.
(the default is 100)
CPARM(10) Return the star pixel location if CPARM(10) <= -1.0,
otherwise return the star RA and DEC The stars file assumes
RA and Dec in the plotting routines.
You can view the contents of the ST file with PRTAB. You can plot it
on images with GREYS, CNTR, PCNTR, KNTR and others.