AIPS HELP file for RMSD in 31DEC24
As of Fri Apr 19 22:21:06 2024
RMSD: Creates an image of the local RMS around each pixel
INPUTS
INNAME Input image name (name)
INCLASS Input image name (class)
INSEQ 0.0 9999.0 Input image name (seq. #)
INDISK 0.0 9.0 Input image disk unit #
OUTNAME Output image name (name)
OUTCLASS Output image name (class)
OUTSEQ -1.0 9999.0 Output image name (seq. #)
OUTDISK 0.0 9.0 Output image disk unit #.
BLC Bottom left corner of input
TRC Top right corner of input
IMSIZE Size of the box used to
calculate rms, in pixels
IMSIZE(2)=-1 => the circle
of diameter=IMSIZE(1)is used
OPCODE 'RMS ','MEAN','BLAN',
'MAD ','MEDI'
(see help), ' ' => 'RMS'
OPTYPE 'ROBS', 'HIST'
(see help), ' ' => 'ROBS'
SCALR1 DataSCALR2 >0 =>
ABS(DATA) < SCALR2*RMS
are replaced by blank
(OPCODE='BLAN')
<0 =>
ABS(DATA) > ABS(SCALR2)*RMS
are replaced by blank
(OPCODE='BLAN')
0 => no blanking
SCALR3 Robust mean exclusion factor
abs(data-mean)>SCALR3*rms
are excluded. 0 -> 3.
FLUX Data with RMS>FLUX
are replaced by blank
(OPCODE='BLAN')
0 => no blanking
XINC Increment at X to calculate
RMS, in pixels
YINC Increment at Y to calculate
RMS, in pixels
The intermediate points are
calculated by interpolation
HELP SECTION
RMSD
Task: Creates an image of the local RMS around each pixel over all
planes of an image cube. The rms is calculated for each pixel
based on the data in a box surrounding the pixel. The size of the
box is controlled by the user (adverb IMSIZE). RMS is calculated
in a multi-iteration (30) "robust" basis. In the first iteration
the RMS is calculated using all points in the box. After that,
points which differ from the mean by more than SCALR3*RMS are
excluded from the consideration for the next iteration.
The iteration process is terminated if none point is excluded.
The input image should have the standard sequence of axes with
two celestial axes followed by a spectral axis.
Adverbs:
INNAME.....Input image name (name). Standard defaults.
INCLASS....Input image name (class). Standard defaults.
INSEQ......Input image name (seq. #). 0 => highest.
INDISK.....Disk drive # of input image. 0 => any.
OUTNAME....Output image name (name). Standard defaults.
OUTCLASS...Output image name (class) Standard defaults.
OUTSEQ.....Output image name (seq. #). 0 => highest unique.
OUTDISK....Disk drive # of output image. 0 => highest
BLC........Bottom left 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.
IMSIZE.....Size of the box used to calculate rms, in pixels
IMSIZE(2)=-1 => a circle of diameter = IMSIZE(1) is used,
instead of a rectangle IMSIZE(1) x IMSIZE(2)
OPCODE.....'RMS ' => creates map of RMSes calculated for each pixel
using the data inside of the given box surrounding
the pixel.
'MEAN' => creates map of MEANes calculated for each pixel
using the data inside of the given box surrounding
the pixel.
'BLAN' => the image value is replaced by BLANK under
control of adverbs SCALR1 and SCALR2 and calculated
RMS. This option prepares the image cube to be ready
for other tasks (XMOM for example) that require cutoff
the 'bad' points on the basis of rms calculated in the
vicinity of each image point.
'MAD ' => creates image of the median absolute deviation or
MAD = 1.4826 * median ( abs (x - median(x)) )
where the factor converts to an "rms equivalent"
ignores OPTYPE and SCALRn
'MEDI' => creates image of the median in the box centered
on the pixel; ignores OPTYPE and SCALRn
' ' => 'RMS '
OPTYPE.....Concept of RMS' calculation
'ROBS' => The far away points are rejected at the multi
iteration process
'HIST' => The histogram concept is used. Data for histogram
are at the range -+ 1.5sigma. The histogram is
calculated at 16 intervals with center at the
mean value
SCALR1.....In OPCODE='BLAN' only, data values below SCALR1*RMS are
replaced by BLANK.
SCALR2.....In OPCODE='BLAN' only, when SCALR2 > 0.0, data values less
in absolute value than RMS*SCALR2 are replaced by blank.
When SCALR2 < 0.0, data values greater in absolute value
than ABS(SCALR2) are replaced by blank.
When SCALR2=0, no replacement by blank
SCALR3.....In robust determination of the mean/rms, values differing
from the current mean by more than SCALR3 * current rms are
excluded from the computation of mean/rms in this
iteration. 0 -> 3.
FLUX.......Data with RMS>FLUX are replaced by blank (OPCODE='BLAN')
FLUX is in Jy/beam
0 => no replacement by blank
Replacement by blank is carried out (OPCODE='BLAN')
if 'SCALR1' .OR. 'SCALR2' .OR. 'FLUX'
XINC.......Increment at X to calculate RMS, in pixels
YINC.......Increment at Y to calculate RMS, in pixels
The task RMS requires a lot of computing time. XINC, YINC are invented
to weaken the computing time problem. The RMS is calculated every
XINC, YINC at the X,Y directions. The RMS of intermediate points are
estimated by interpolation. The computing time should be reduced
by the factor XINC*YINC
Programmer Leonia Kogan
EXPLAIN SECTION