Adding an Eccentricity filter to livestacking?

Got an idea for something that SharpCap should do? Share it here.
Forum rules
'+1' posts are welcome in this area of the forums to indicate your support for a particular feature suggestion. Suggestions that get the most +1's will be seriously considered for inclusion in future versions of SharpCap.
Post Reply
timh
Posts: 515
Joined: Mon Aug 26, 2019 5:50 pm

Adding an Eccentricity filter to livestacking?

#1

Post by timh »

Hi Robin,

The frame brightness and FWHM filters are very useful I find. The other main parameter I use for selection in postprocessing (apart from noise estimation which is based on the background noisiness) is Eccentricity -- which cuts down the number of frames with flared or funny-shaped stars.

Is a global Eccentricity estimation the kind of calculation that can be carried out fast enough for livestacking?

thanks

Tim H
User avatar
admin
Site Admin
Posts: 13177
Joined: Sat Feb 11, 2017 3:52 pm
Location: Vale of the White Horse, UK
Contact:

Re: Adding an Eccentricity filter to livestacking?

#2

Post by admin »

Hi Tim,

yes, actually the eccentricity comes out of the star detection code already, but SharpCap does nothing with it (beyond a very mild filter that throws away stars with very high eccentricity).

If you have some sample frames (good one, bad one, otherwise minimal difference between them) I can try a manual test on them to see if the code is any good at picking up mis-shaped stars or not. That would indicate whether this might work.

cheers,

Robin
timh
Posts: 515
Joined: Mon Aug 26, 2019 5:50 pm

Re: Adding an Eccentricity filter to livestacking?

#3

Post by timh »

Hi Robin,

Thankyou. That would be great. Attached here are 10 FIT files of the core of M92.

https://onedrive.live.com/?id=330584F8B ... F8B152FA32


All were selected (by PI subframe selector) as FWHM <2.4 and Stars > 80 (using star number as a 'brightness' indicator). They probably represent a pretty tough test since they are quite noisy and only 0.2s exposure time (at ca F 4.2). If they are too difficult I can easily send some that are less noisy .

The first 5 were further selected for Eccentricity < 0.60 and the latter 5 for Eccentricity > 0.80. The difference is quite apparent visually so they should make for a fair test set.


Tim
Post Reply