plate solve precision?

Posted by Mike Dubson on Jun 16, 2019; 8:47pm
URL: http://astroimagej.170.s1.nabble.com/plate-solve-precision-tp1160.html

Hi, I'm a new user with a couple of questions regarding plate solution.
Question 1: After I plate solve an image, how can I see the plate scale, that is, the arc-seconds per pixel?  I see it displayed approximately right on the image (there is a scale bar marked in arcsec or arcmin and I can count pixels), but I want to know the plate scale as precisely as possible.
Question 2: After I plate solve an image, I would like to have some information about the residuals of the solution, namely, how accurate is the solution?  I am doing astrometry on near-earth asteroids, and I would like some estimate of the uncertainty in the position determinations. I don't mean uncertainty in the centroid of the asteroid image due to photon count statistics, I mean the precision of the WCS plate solve itself. -thanks!