Platesolving fails most of times

[Luca Leombruni]

Hi Dustin, 

I've a problem with platesolving. I managed to make Astrometry work on my system (Manjaro) without errors, and sometimes, but only rarely, platesolving works, most of times it doesn't.

I've a Celestron 6SE, a 0.63 focal reducer and a ZWO 224, resulting in a FOV of 17x13 arcmin, so I downloaded from index-4203-xx.fits to index-4206-xx.fits and index-4107.fits (actually I've also tried to platesolve using indexes until 4200 with no results).

As an example, I'm trying to platesolve the image you can find at http://nova.astrometry.net/user_images/3367599 (Job 3915192).

The online system is able to resolve it flawlessly, I'm not.

I'm trying to run 

solve-field -O -v --no-plots --no-verify --resort --downsample 2 -L 10 -H 20 -u aw -3 190.005 -4 -11.608 -5 30 fitsONDDqe.fits

but I'm getting "Did not solve (or no WCS file was written)."

I've also tried the following switches:

--tweak-order 2

--sigma 100 

--c 0.02

and also tried to increase downsampling as they're suggested by some users around, but still no joy.

What I'm missing?

[Russell Valentine]

It solves very fast for me if you don't include --no-verify

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[Russell Valentine]

Haha.. horrible reply, solves fast because the header basically already included the solve.

I also have the problem where some images I can't solve locally but it solves online in astrometry.net I assumed it was because the online version has different index files not available to everyone.

[Luca Leombruni]

Hi Russell, 

hehe, indeed. Anyway, thanks for replying (and refining your reply afterwards)!

I see your point, since the image contains already WCS data why ignoring them?

In the past three weeks I've smashed my head against this problem and I'm quite sure I tried altready what you suggested me, but you know, I've lost track of my experiments, so I issued the command again without the --no-verify switch, and it keeps failing.

So this is interesting, let me ask some questions about your try. You wrote "It solves very fast for me",

1) did you platesolve by yourself the image I uploaded on nova.astrometry, or were you talking in general?

2) which indexes do you have installed in your system? 

3) which is generally the command (including the switches) you issue successfully?

I forgot to mention yesterday that I get a warning as soon as I issue the solve-field command:

/usr/lib/python3.8/site-packages/pyfits/__init__.py:21: PyFITSDeprecationWarning: PyFITS is deprecated, please use astropy.io.fits

I'm trying to install astropy but it throws an error while downloading, python-jinja module is missing (I'm on AUR), so since it's only a warning I think it doesn't affect the result (I don't get any error while running the command) and it can be ignored by now, or am I wrong?

I also redirected the solve-field output (the verbose one) on a file, which I'm posting here, in case someone wants to give a look.

For the moment thank you to everyone.

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