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Different pixel_scales
11-20-2008, 23:23
Post: #1
Different pixel_scales
Hi

I am trying to do photometry in sextractor two-image mode,
so I want to resample one of my image to another one.
But these two images came from from different instrument and
the pixel_scales are 0.225" and 0.258". When I resample my
0.225" pixel scale image using the pixel_scale as 0.258" ,
I find it introduce a big error mag_rms ~ 0.3 for the 18-20
magnitude stars.

The resample type I used is LANCZOS3

Is there anything to reduce this error?
Thanks very much

Fuyan
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12-02-2008, 15:59
Post: #2
RE: Different pixel_scales
If the error is not systematic, it may be the sign that your input data are undersampled. In that case you might want to set RESAMPLING_TYPE to BILINEAR and OVERSAMPLING to 3 (for example).
- Emmanuel.
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