Description:
Takes the regridded image and adds in data of value ’zero’ for any points that are
within range of the weighting function (ie if TOTAL_WEIGHT is greater than 0) but that do not
already contain any data (ie TOTAL_WEIGHT is set to something becuase regrid_1 determined that
the pixel was close enough to be influenced by the convolution function, BUT no data was actually
found to lie in that pixel). This has the effect of enforcing zero flux density at the edges of the map or
where no data was present (eg surrounding a bad pixel). This is only really necessary for the bessel
function regrid since that function is extremely sensitive to edge effects. Once the ’guard ring’ has
been processed, the output image is normalised by dividing by the convolution weight
(ie the actual weight used for each pixel). Any point that has zero convolution weight
is set to bad.
Invocation
CALL SCULIB_WTFN_REGRID_3 (METHOD,RES,PIXSPACE, NI,
NJ, ICEN, JCEN, TOT_WEIGHT_IN, WAVELENGTH, CONV_DATA_SUM, CONV_VARIANCE_SUM,
CONV_QUALITY_SUM, CONV_WEIGHT, WEIGHTSIZE, SCLSZ, WTFN, STATUS)
Arguments
USEGUARD
= LOGICAL (Given)
Logical to determine whether the gueard ring should be used.
RES = INTEGER (Given)
number of resolution elements per scale length
PIXSPACE =
REAL (Given)
the pixel spacing of the output pixels (radians).
NI = INTEGER (Given)
The number of output pixels in the x direction.
NJ = INTEGER (Given)
The number of
output pixels in the y direction.
ICEN = INTEGER (Given)
the x index of the centre of the
output array.
JCEN = INTEGER (Given)
the y index of the centre of the output array.
TOT_WEIGHT_IN (NI, NJ) = REAL (Given)
the ‘total weight’ of each output pixel.
WAVELENGTH = REAL (Given)
the wavelength at which the maps was made (microns).
CONV_DATA_SUM (NI,NJ) = REAL (Given and returned)
the convolution sum for each output
pixel.
CONV_VARIANCE_SUM (NI,NJ) = REAL (Given and returned)
the convolved variance sum
for each output pixel.
CONV_QUALITY_SUM (NI,NJ) = BYTE (Given)
the quality on the
convolution sum for each output pixel.
CONV_WEIGHT (NI,NJ) = REAL (Given and
returned)
the convolution weight for each output pixel.
WEIGHTSIZE = INTEGER
(Given)
radius of weight function in scale units (SCUIP__FILTRAD for BESSEL, 1 for
LINEAR)
SCLSZ = REAL (Given)
1 scale length in the same units as pixspace
WTFN (RES
RES
WEIGHTSIZE
WEIGHTSIZE) = REAL (Given)
convolution weighting function
STATUS = INTEGER (Given and
Returned)
The global status.
Copyright
Copyright ©1995,1996,1997,1998,1999 Particle Physics and
Astronomy Research Council. All Rights Reserved.