MOPEX User's Guide - IRSA

MOPEX User’s Guide
Fine Res = 0 as the Fine Res option is not fully implemented in the presence of bad
pixe ls.
2. Drizzle: Each input pixel is shrunk Drizzle Factor (float) times its origina l size along
each axis, e.g. 0.5. The value of the shrunken pixel is the same as the original pixel. The
shrunken pixels are then projected onto the output pixels with their values distributed into
output pixels according to area overlap.
3. Grid: This method is intended to create a crude first-look mosaic quickly. Each input
pixel is filled with Grid Ratio (int) squared grid points. Each grid point is assigned the
value of the pixel it belongs to. Each grid point is projected onto the output frame and the
flux associated with the grid point is added to the output image pixel into which the grid
point was projected. You may not run the Mosaic Reinterpolate module with this option.
The gain in speed is up to 10 times that of the Default method. The price you pay is the
fidelity of the interpolated images, so in general these should not be used for science.
4. Cubic This method uses a bicubic interpolation. It is like the Default method except
that each output pixel is a weighted sum of the 16 nearest input pixels, with the weights
determined by bicubic polynomials. A tunable parameter Alpha (float) pins the weights.
The default value of -0.5 should be used. Note: this method could be useful in high S/N
cases because it enforces smoothness in the interpolation function, but the major
drawback is significantly more noise correlation than the Default linear interpolation.
Mosaic Interpolate output subdirectory: The subdirectory of that you wish
to use for the output files. Default is Interp-apex.
COMMAND LINE INPUT
&MOSAICINTIN
INTERP_METHOD = 1,
FINERES = 0,
DRIZ_FAC = 1,
GRID_RATIO = 4,
ALPHA = -0.5,
&END
In Global Parameters:
INTERP_DIR = Interp-mosaic
OUTPUT
Point Source Extraction (APEX) 120
APEX Modules