Is PSF generated by DynamicPSF always elliptical?

Yannis Doukakis

Active member
May 19, 2020
Thessaloniki, Greece
As I understood, DynamicPSF "fits" a series of pre-defined star shape distributions over your selected stars, figures out the parameters and thengenerates a "clean" PSF which is either circular or elliptical.
Is there any way, to generate the PSF just by "stacking" the selected stars?
I am asking mainly if it is possible to try to "reverse" coma or other aberrations locally or "drop" like stars due to errors in guiding. Like the <I_will_not_mention_the_name_again> Shake reduction works, which practically is also Deconvolution.

Juan Conejero

PTeam Member
Sep 2, 2004
Valencia, Spain
To answer your initial question about elliptical PSFs, you can enable the Circular PSF option in DynamicPSF to compute circular functions exclusively.

To generate a synthetic PSF image, which you can use in several tools (such as Convolution, Deconvolution and RestorationFilter), select the stars that you want to include and click the 'camera' icon. This will render all selected PSFs as images and will 'stack' them as a single image.

As for reversing or 'undoing' tracking errors, no, these instrumental errors cannot be fixed effectively. You can 'make up' them using software, but the data that has been lost cannot be recovered and any real solution must be implemented at the hardware level.

As for coma and other off-axis optical aberrations, we still don't have an anisotropic deconvolution implementation, although it is in our to-do list. These algorithms can help reducing the effects of these optical aberrations, but as before, really valid solutions can only exist at the hardware level.

And you can mention it 😉