ImageSolver and NGC 3521

[Jarmo Ruuth]

Hi.

I am unable to get ImageSolver to solve the recent data set of NGC 3521.

If you have succeeded in solving NGC 3521 any tips would be very welcome. I did see the post from Reggie but I guess CHI-1 does not have the same issue. Also other CHI-1 data solves just fine.

This is the error I get:

** 0 star pair matches found - need at least 3 matched stars.
*** Error: Unable to find an initial linear transformation.
<* failed *>
*** Error: The image could not be aligned with the reference star field.’

Below are my settings. XBINNING is 2 so the image in binned.

Image metadata for SolveImage:
  coordinates RA DEC: 166.4524882164959 -0.03685555163455789
  focal length: 3962
  resolution: 0.00010874918272043893
  xpixsz: 7.52
  referenceSystem: ICRS
  useFocal: true
  topocentric: false

Regards,
Jarmo
 

[Reggie Jones]

Hi Jarmo; I had the same problem with this dataset.  I talked with Adam Block about it and he provided the following answer which can also be found in the PixInsight Forum here; https://pixinsight.com/forum/index.php?threads/spcc-failure.22572/

 

There are too few GAIA stars with spectra in the field of view (only 5).  You will have to resort to PCC.  To date this is the only place in the sky known to have two few stars for this field of view.  It's rare to have this happen but the problem exists for this dataset.

I used Photometric Color Calibration (PCC) on this dataset and everything worked fine and I got a good result.  PCC will do a plate solution within the process, so you do not need to use Image Solver.

Hope this helps.  The good news is it isn't anything you did wrong.

Reggie

 

 

[Jarmo Ruuth]

Hi Reggie, Thanks for the info! Need to check with PCC.

Regards,
Jarmo

[Phil Misiowiec]

Thanks, Jarmo and Reggie. I came to the forum today looking to solve this exact problem (NGC 3521). I played with the various SPCC levers but none worked, so on to PCC. 🙂