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Use of Drizzle function to improve low resolution spectra?????
Posted: 10 Dec 2018, 16:31
by Forum_2017
I've just seen a spectral image taken with a SA200 grating which seems to have dramatic improved when stacked and "Drizzled" combined.
https://en.wikipedia.org/wiki/Drizzle_( ... rocessing)
Is this a function which could be added to AstroArt6??????
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Re: Use of Drizzle function to improve low resolution spectra?????
Posted: 10 Dec 2018, 16:31
by Forum_2017
Hmmm
I found the reference to Drizzle but not the method of applying during pre-processing???
From the Help menu:
Drizzle 200%. Doubles the size of all images to increase the resolution IF THE IMAGES ARE UNDERSAMPLED. You can easily recognize an astronomical undersampled image: its stars are 1 - 2 pixels wide, they look like hot pixels. For a good result the images must not be aligned. A minimum of 10-20 images is recommended. If the result image if affected by a chequered artefact then it can be corrected with one of the following convolution kernels: (4-2-2-1 for faint artefacts and 1-1-1-1 for strong artefacts).
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Re: Use of Drizzle function to improve low resolution spectra?????
Posted: 10 Dec 2018, 16:31
by Forum_2017
Hello, the option is in the Extra page of Preprocessing, inside the Resize box.
By the way, nowadays is almost useless, there is no chance to have an undersampled image with modern multimegapixels camera, unless you are using an extremely short focal.
Re: Use of Drizzle function to improve low resolution spectra?????
Posted: 10 Dec 2018, 16:31
by Forum_2017
Fabio,
Thanks for that - found it!!
I've just seen a low resolution spectrum which appears to show "improvement" when drizzle combine is used - trying to find out more details on the process/ method.
Ken