M78 CHI-1 CMOS Image Solver Problem

[Reggie Jones]

Working with the recent M78 CHI-1 CMOS data taken late November 2023.  Trying to get an astrometric solution for an RGB combined linear image so that I can use SPCC via the Image Solver script but it won't plate solve.  Anyone else have this issue and was able to get it corrected?

[George Hatfield]

I have had this happen numerous times.  Some suggestions....   

Search on M78 and make sure the coordinates are correct.

Ensure the focal/length or resolution (arcsec/pixel) is correct for the Planewave cdk24 (0.39 arcsec/pixel).

Make sure the pixel size is correct for the camera (3.76 microns).

George

 

 

  

 

 

[Reggie Jones]

12 hours ago, George Hatfield said:

I have had this happen numerous times.  Some suggestions....   

Search on M78 and make sure the coordinates are correct.

Ensure the focal/length or resolution (arcsec/pixel) is correct for the Planewave cdk24 (0.39 arcsec/pixel).

Make sure the pixel size is correct for the camera (3.76 microns).

George

 

 

  

 

 

Thanks George - I'd already double checked the coordinates and camera pixel size which I know are correct.  However, the resolution for this setup is not always what you'd expect - I think normally they use 2x2 binning on this telescope / camera setup and sometimes use 4x4.  I haven't specifically played around with this yet but it's my next step.

[Bret Spencer]

I find that I have to multiply the pixel size by the binning factor to get the image solver to work. I had some 4x4 bin images from SPA-2-CMOS (3.76 micron pixel size). It wasn't until I tried various numbers around 12-15 in the image solver script that it would work. I'd never heard of that before I tried it. Maybe it was a fluke.

I recall a video by Adam Block regarding WBPP where he indicated that unless you are in the ballpark on the pixel size the solve can be sketchy.

[Jarmo Ruuth]

I have found out that you should adjust the values if you use binning or drizzle (2x).