I just recently "discovered" the Weighted Batch Preprocessing, but only use it to calibrate my frames. After that, I end up with calibrated and "cosmetic corrected" data which I normally align with StarAlignment (using the frame with the best FWHM and Eccentricity as reference image) and to the image integration. That last one with the "weight" factor set to "SNRWeight". Because WBPP uses several factors (i.e. FHWM, Eccentricity, SNR) when it integrates images (which I don't use, I only use WBPP for calibration) I wondered if it was possible to add some kind of weight factor dat is based upon these values. And it is!
In my case –with a monochrome CCD– I just load the calibrated images into SubFrameSelector (one filter at a time) and measure them, writing down the highest and lowest values of FWHM, Eccentricity and SNR. After that I use a expression –which can be altered at your taste– after which SubFrameSelector calculates the weight of each frame. I then output the frames using SFS and adding the FITS-keyword "SFSWEIGHT". This keyword can later on me used as a weight factor during ImageIntegration.
The formula, in my case, looks like this:
(20*(1-(FWHM-2.390)/(3.740-2.390)) + 15*(1-(Eccentricity-0.3529)/(0.7022-0.3529)) + 25*((SNRWeight-1.013)/(1.196-1.013)))+40
The numbers in red are all multiplication factors, the blue variables are the FITS keywords SFS finds in the FITS header of the images and the green constant
is a pedestal to bring the outcome of the expression in the range from 0-100. All other numbers you see are the minimum and maximal values of resp. the FWHM, Eccentricity and SNR. The only thing the formula does is bring the actual value of these factors into a normalized range. The "1 minus you see at the beginning of FWHM and Eccentricity is to make sure that a smaller value adds more weight (lower values are better). This is not the case with the SNR (the higher this value the better it is).
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