Login  Register

Re: Astrometry Settings Issue - Limit Max Peaks in 8-bit Images

Posted by karenacollins on Mar 27, 2021; 9:01am
URL: http://astroimagej.170.s1.nabble.com/Astrometry-Settings-Issue-Limit-Max-Peaks-in-8-bit-Images-tp1530p1533.html

Hi Matt,

Thanks for the image. After running a plate-solve on your image, I realized what is causing the stars with greater than 250 peak counts to be included in the plate-solve. As it turns out, the median filter is applied before the max peak count cut, and I expect you have that option enabled. If you really want to cut on the actually pixel values, you can disable the median filter option and see that the stars you circled are not included in the plate solve (i.e. will have no blue circle). That said, the plate-solve seems to complete fine with or without the brighter stars included.

This sequence of operations could be considered backwards, but it's a limitation of the implementation because the median filter, if enabled, needs to run before the source detection routine runs, so I think we are stuck with the awkwardness, unless the median filter is disabled.

Karen

On 3/26/2021 9:14 AM, mketi [via AstroImageJ] wrote:
Hi Karen,

It looks like the forum environment does not accept FITS files, so I'll send it to your email.

I've annotated the saturated objects that are circled in the plate solve animation. Hopefully the annotations show up on other computers, though I do see some entries in the FITS header. The troubled plate solving setting is Limit Max Peaks = 250. I'll also include a screenshot of everything that I used.

Thank you again!

Matt


If you reply to this email, your message will be added to the discussion below:
http://astroimagej.1065399.n5.nabble.com/Astrometry-Settings-Issue-Limit-Max-Peaks-in-8-bit-Images-tp1530p1532.html
To start a new topic under AstroImageJ, email [hidden email]
To unsubscribe from AstroImageJ, click here.
NAML