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20th March 2020 - APP 1.078 has been released !

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Mosaic problem  

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(@einari)
White Dwarf Customer
Joined: 2 years ago
Posts: 17
January 31, 2020 12:04  

Hello,

Any advice what I should change to get rid of artifacts ?

mosaic crop

This topic was modified 2 months ago by Vincent Groenewold - Moderator

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(@vincent-mod)
Quasar Admin
Joined: 3 years ago
Posts: 1435
February 5, 2020 15:36  

That looks kind of weird, did you use settings like LNC and MBB?


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(@einari)
White Dwarf Customer
Joined: 2 years ago
Posts: 17
February 5, 2020 19:46  

Yes I did.

LNC 1 iteration of LNC at a scale of 1 and 15% MBB.


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(@vincent-mod)
Quasar Admin
Joined: 3 years ago
Posts: 1435
February 5, 2020 20:55  

Could you try upping MBB a bit and going for LNC 1st degree, with 3 iterations? What is the overlap in your panels?


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(@einari)
White Dwarf Customer
Joined: 2 years ago
Posts: 17
February 8, 2020 20:23  

Thanks Vincent. Your suggestions seem to have helped.

I had default SGP overlap so 15%.


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(@vincent-mod)
Quasar Admin
Joined: 3 years ago
Posts: 1435
February 9, 2020 10:31  

That's great to hear! Thanks.


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(@einari)
White Dwarf Customer
Joined: 2 years ago
Posts: 17
February 10, 2020 10:41  

Hm, it worked in one colour channel mosaic but now I'm struggling with blue channel.

It might be lack of #stars - after I calibrated&stacked I get 36 to 79 stars in panel.

And now when I try to make mosaic of those I get this error in Register:

Encountered error in module:
MultipleViewDistortionAndCalibrationTask

Error message:
java.lang.ArrayIndexOutOfBoundsException: 3

Cause:
3
pd.a(Unknown Source)
pd.doInBackground(Unknown Source)
javax.swing.SwingWorker$1.call(SwingWorker.java:295)
java.util.concurrent.FutureTask.run(FutureTask.java:266)


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(@vincent-mod)
Quasar Admin
Joined: 3 years ago
Posts: 1435
February 10, 2020 13:01  

So how are you creating the mosaic exactly, are you trying to create the mosaic per channel?


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(@einari)
White Dwarf Customer
Joined: 2 years ago
Posts: 17
February 10, 2020 14:46  

Yes, now I'm trying to do blue channel of 2x2 mosaic.

I've tried first calibrate/stack individual panels ant then doing mosaic.

And I've tried loading all mosaic images and doing calibrating/stacking/etc in one go.


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(@vincent-mod)
Quasar Admin
Joined: 3 years ago
Posts: 1435
February 10, 2020 15:25  

So, making a mosaic of each channel is not the way to go at least. * It should be possible to just make the panels first into an RGB stack, then create the mosaic with those panels. That doesn't work? If not, you may have a data issue indeed.

* Well, it is possible, but you do need proper signal in all channels, making RGB panels first is usually better. Only when you need to add H-alpha or other narrow-band data, you go the only R, only G and only B mosaic mode.

This post was modified 2 months ago 2 times by Vincent Groenewold - Moderator

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(@einari)
White Dwarf Customer
Joined: 2 years ago
Posts: 17
February 10, 2020 16:28  

Well, it worked for R and G channels but not with B.


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(@vincent-mod)
Quasar Admin
Joined: 3 years ago
Posts: 1435
February 10, 2020 16:32  

It might be that there is not enough signal for a mosaic, I usually set APP to detect at least 1000 stars in a mosaic, 500 should also work but more is better in this case. But you did try to make each panel into a RGB first right?

If you could upload some of the data, I could have a look as well if you want.

This post was modified 2 months ago 2 times by Vincent Groenewold - Moderator

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(@einari)
White Dwarf Customer
Joined: 2 years ago
Posts: 17
February 10, 2020 17:57  

It could be that my problem now is too narrow view (and too few stars).
2x2 mosaic was taken with 1390mm fl , 30.9 x 24.7 arcmin fov and 0.674 arcsec/pixel.

Just processing now 4 panel RGB mosaic.
Hopefully it works better.

But I really appreciate your helping efforts.


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(@einari)
White Dwarf Customer
Joined: 2 years ago
Posts: 17
February 10, 2020 18:07  

Not that good - needs more normalizing.

Here's a link if you would like to have a go.
https://drive.google.com/open?id=1n7BQnR_mRs07UxHgOkq2X1bCvEw5M-fR

Please share settings if you get decent result.


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