Re: [Astrometry] Solved in Tycho II but failed in Gaia.

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Dustin Lang

Dec 2, 2021, 8:48:53 AM12/2/21
to Shen Ming, astrometry
This is not surprising.  Your image is > 6 degrees wide.  The 5200-series only covers up to scale 6, ie, will work on images up to about 1 degree across.


On Wed, Dec 1, 2021 at 8:33 PM Shen Ming <> wrote:
Dear all:
    I was handling a fits file.
    I tried to solve it with Tycho 2 first, every thing is ok:
    When I tried to solve it with index 5200,  it failed by reporting 'CPU time limit'. Thus I added the arguments -L -H -u derived from Tycho2 results, the program told me  'did not solve', please see the snapshot attached:

BTW: I also tried 2mass (index 4200) , the result looks similar to the Tycho 2. 

I wonder what's happening in GAIA situation.

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Toni Šarić

Dec 12, 2021, 3:53:03 PM12/12/21
to astrometry
How do you know which 41xx indexes to download based on the width of your image?
README says how to calculate for 42xx indexes, but nothing for 41xx series.

Dustin Lang

Dec 12, 2021, 4:43:44 PM12/12/21
to Toni Šarić, astrometry
The scales are the same between 41xx and 42xx -- xx == xx.

Toni Šarić

Dec 13, 2021, 10:39:54 AM12/13/21
to astrometry
Oh great, thanks.
I just tried 4100 series, and it seems that it gives more precise results (so far).

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