int_qual (Oct93)               qasun              int_qual (Oct93)



NAME
    int_qual -- image quality analysis  for  intensity  images.   Images
    are  checked for partial images, distorted images, systematic noise,
    low intensity and bad edges.  The images may be elliptical.
    
    
USAGE
    int_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)
    
    
PARAMETERS
    
    inputl
        input image or list of images
    
    qa_param_fil
        output image of image QA parameters
    
    epoch_time
        string containing the full date and time of time slot  0.   Form
        is "yyyy/mm/dd.hh:mm:ss".
    
    nom_intens 
        minimum acceptable intensity at the center of the disk.
    
    (del_image = 60) 
        integer number of seconds between images.
    
    (seconds = no)
        Should  the  seconds  be  included when computing the image time
        slot?.
    
    (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
        evaluation.
    
    (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.
    
    (int_toler = 0.5)
        Images  with  central  intensity  of   (intensity/nom_intens   < 
        int_toler)  are  not  subjected  to any tests beyond the partial
        image test.
    
    (verbose = no)
        Should the ASCII output for unflagged images be written out?
    
    (image_band = 3)
        The number of the intensity band, for three dimensional images.
    
    
IMAGE HEADER WORDS
    
    DATE-OBS
        Date of observation in UT, format yyyy/mm/dd
    
    TIME-OBS
        Time of observation in UT, format hh:mm:ss
    
    FNDLMBXC
        x-direction center of the disk in pixels
    
    FNDLMBYC
        y-direction center of the disk in pixels
    
    FNDLMBMI
        length of the semiminor axis in pixels
    
    FNDLMBMA
        length of the semimajor axis in pixels
    
    FNDLMBAN
        angle between the semimajor axis and the y axis in degrees
    
    SER_SLOT
        This used if the date and time of observation  are  not  present
        under the image header words DATE-OBS and TIME-OBS.
    
    
DESCRIPTION
    Task  INT_QUAL  flags single images that fall outside the range of a
    set of quality standards.  These  are  (to  be  inserted  in  detail
    later)
    
    
    
EXAMPLES
    1.    Assess  the  image  quality  of  solar  disk  images  in  list 
    in27may.lis.  The image quality parameter outputs  will  be  written
    to  the  image qai27may.  The ASCII outputs will be collected in the
    file qai27may.dat.  The nominal central  intensity  is  1.0e6.   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> int_qual @in27may.lis qai27may "1993/05/27.14:26:00" 1.0e6 
                    > qai27may.dat


    2.    Assess  the  image  quality  of  solar  disk  images  in  list 
    mtw10june.lis.  The image quality parameter outputs will be  written
    to  the  image qaimtw10june.  The ASCII outputs will be collected in
    the  file  qaimtw10june.dat.   The  nominal  central  intensity   is 
    1.2e6.   The  first  available  image  has  date 1992/06/10 and time
    14:00:15.  The images are 75 seconds apart, and the seconds  in  the
    image  time  stamp  should  not  be ignored.  However, the time slot
    numbers have already been inserted because the image time  stamp  is
    not  under  the  usual image header words.  Note that the time input
    is for slot 0--in this case, 75  seconds  before  the  first  image.
    The intensity is in band 1 of the input image
    
            qa> int_qual @mtw10june.lis qaimtw10june "1992/06/10.13:59:00" 1.2e6 
                    del_image=75 image_band=1 > qaimtw10june.dat
    
    
    
    
TIME REQUIREMENTS
    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.