mod_qual (Oct93) qasun mod_qual (Oct93)
mod_qual -- image quality analysis for modulation images. Images
are checked for partial images, distorted images, systematic noise,
low intensity and bad edges. The images may be elliptical.
mod_qual inputl qa_param_fil epoch_time nom_intens (del_image seconds
write_head square_side line_length spot_toler edge_toler wave_toler
int_toler verbose image_band)
input image or list of images
output image of image QA parameters
string containing the full date and time of time slot 0. Form
(del_image = 60)
integer number of seconds between images.
(seconds = no)
Should the seconds be included when computing the image time
(write_head = no)
Should the history and time slot be written in the image header?
(square_side = 17)
Number of pixels on a side for the image spot checks and the
width of the swaths.
(line_length = 9)
Number of pixels for the line length for the image edge
(spot_toler = 0.2)
Images with any on-disk spot ratio less than (1.0-spot_toler)
are flagged for examination. The on-disk spot ratio is the
ratio of the intensity in each quadrant at half of the disk
radius to the central intensity.
(edge_toler = 2.)
Images with ratios of pixel sums used to check the edge quality
greater than edge_tol are flagged for examination.
(wave_toler = 0.25)
Images with (horizontal sigma/vertical sigma) <
(1.00-wave_toler) or (horizontal sigma/vertical sigma) >
(1.00+wave_toler) are flagged for examination.
(mod_toler = 0.85)
Nominal central value of modulation. Images with average
central modulation of modulation < mod_toler are flagged for
(verbose = no)
Should the ASCII output for unflagged images be written out?
(image_band = 2)
The number of the modulation band, for three dimensional images.
IMAGE HEADER WORDS
Date of observation in UT, format yyyy/mm/dd
Time of observation in UT, format hh:mm:ss
x-direction center of the disk in pixels
y-direction center of the disk in pixels
length of the semiminor axis in pixels
length of the semimajor axis in pixels
angle between the semimajor axis and the y axis in degrees
This used if the date and time of observation are not present
under the image header words DATE-OBS and TIME-OBS.
Task MOD_QUAL flags single images that fall outside the range of a
set of quality standards. These are (to be inserted in detail
1. Assess the image quality of solar disk images in list
mo27may.lis. The image quality parameter outputs will be written
to the image qam27may. The ASCII outputs will be collected in the
file qam27may.dat. The first available image has date 1993/05/27
and time 14:27:03. Note that the time input is for slot 0--in this
case, one minute before the first image.
qa> mod_qual @mo27may.lis qam27may "1993/05/27.14:26:00"
The time requirements for the intensity QA on about 700 GONG
prototype images on a DECstation 5000/200 is about 5 minutes.
BUGS and CAUTIONS.
The time slot fixer can't reliably deal with time changes that
cross year boundaries. The list colating code list_col can't
currently deal with slot numbers above 1440.