Author Topic: Catalog Star Generator problem  (Read 137 times)

Offline grichard

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Catalog Star Generator problem
« on: 2019 October 13 09:20:02 »
Hello

I am trying to generate a star catalog field for a wide image (20 degree x 20 degrees), to magnitude 15.
This is a wide field and relatively deep, but nothing spectacular by today's standard.

Doing so I am experiencing the same problem as reported on: Jan 22, 2017 and Nov 09, 2018.

Either the star catalog does not download completely, or the script limits its FOV to a smaller value than the one desired. Same problem regardless of the catalog in use or the server hosting the catalog.

I am using the following parameters in the script:
Projection .............. Gnomonic
Resolution .............. 3.828 arcsec/px
Rotation ................ -90 deg
Image center ............ RA: 20 36 05.746  Dec: +39 19 07.47
Image size: ............21,000 x 20,000 pixels
Limiting Mag: ............15


Here is the script listing when it limits itself to a smaller FOV than the one desired:
run --execute-mode=auto "C:/Program Files/PixInsight/src/scripts/AdP/CatalogStarGenerator.js"

Processing script file: C:/Program Files/PixInsight/src/scripts/AdP/CatalogStarGenerator.js

Downloading Vizier data:
http://cdsarc.u-strasbg.fr/viz-bin/asu-tsv?-source=I/312/sample&-c=309.023940 39.318741&-c.bd=18.074593&-c.u=deg&-out.form=|&-out.max=200000&-out=PPMX&-out=RAJ2000&-out=DEJ2000&-out=pmRA&-out=pmDE&-out=Cmag&-out=Rmag&-out=Bmag&-out=Vmag&-out=Jmag&-out=Hmag&-out=Kmag&Vmag=<15
5436920 bytes transferred in 11.47 s @ 462.94 KiB/s
FOV:18.075 actual:12.755
Catalog PPMX size: 50329 objects inside the image

Loaded

Calibrating saturation flux: OK

PixelMath: Processing view: CatalogStars
Executing PixelMath expression: combined RGB/K channels: 0.0001: done
Truncating to [0,1]: done
1.226 s
Painting 50329 stars
Painting end

Saving keywords...
Saving properties...


Otherwise I get this warning:
run --execute-mode=auto "C:/Program Files/PixInsight/src/scripts/AdP/CatalogStarGenerator.js"

Processing script file: C:/Program Files/PixInsight/src/scripts/AdP/CatalogStarGenerator.js

Downloading Vizier data:
http://cdsarc.u-strasbg.fr/viz-bin/asu-tsv?-source=I/317&-c=309.023940 39.318741&-c.r=18.074593&-c.u=deg&-out.form=|&-out.max=200000&-out=PPMXL&-out=RAJ2000&-out=DEJ2000&-out=pmRA&-out=pmDE&-out=Jmag&-out=Hmag&-out=Kmag&-out=b1mag&-out=b2mag&-out=r1mag&-out=r2mag&-out=imag&r1mag=<15
22112627 bytes transferred in 15.89 s @ 1358.90 KiB/s
** Warning: The server has returned an incomplete query. Please reduce the value of the magnitude filter.


Regardless, I am not able to generate a deep star field corresponding to my mosaic. This is a mandatory step to correctly control my image distortion in the subsequent gradient merge mozaic workflow.

Thanks for any tip to move forward.

Below is the mosaic, but without proper distortion control, as I could not get the starfield.

Guillaume

Offline dld

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Re: Catalog Star Generator problem
« Reply #1 on: 2019 October 13 09:45:42 »
Hello Guillaume,

An easier way to do mosaics, without the need of an artificial star field, is by using the MosaicByCoordinates script. Platesolve each panel and use the script to register all the panels together. And then use the GradientMergeMosaic process for the seamless assembly of the registered panels.