VIIRS second image layer speckled

Errors and unexpected results
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hproe
Posts: 499
Joined: Sat Nov 27, 2010 3:46 pm

VIIRS second image layer speckled

Post by hproe »

Hi -

When doing a second image layer with VIIRS data in recent versions of 1.6 beta1, this layer is speckled, i.e. the lower layer shines through like
speckles.png

In 1.5 no speckles.
HP
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Rick
Posts: 404
Joined: Fri Jan 16, 2009 8:20 pm

Re: VIIRS second image layer speckled

Post by Rick »

Hi HP,

Using the latest nightly, I was able to overlay band 15 brightness temperature with band 15 radiance without any speckles. I am running on a Windows 7 workstation. Please let me know the bands and parameters you are using to create your display. Also let me know your operation system.

Rick
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hproe
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Joined: Sat Nov 27, 2010 3:46 pm

Re: VIIRS second image layer speckled

Post by hproe »

Hi Rick -

I have further investigated last night's nightly und Windows 10. It only happens when the image subset is digging well into the bow-tie area. It does not matter what unit/channel is displayed in the 2 layers. I have done TEMP>RAD and RAD>TEMP of M15 and both times the 2nd layer is sprinkled with holes. Deleting the layers (no the data) and re-doing the 2nd layer only reproduces exactly the same hole configuration. Rechecking 1.5: all is fine there. Is there a problem with the bow-tie correction?

HP
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Rick
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Re: VIIRS second image layer speckled

Post by Rick »

Hi HP,

I was able to reproduce the problem over the bow tie region. In the latest nightly, if you try to use swathtogrid to create separate layers, the resolution is not remembered between parameters. This is a new bug and has been written up in Inquiry 2177.

While this is not a perfect solution, if you reselect a region for the second parameter, you should get your desired results. Let us know if that is not the case.

Rick
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hproe
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Joined: Sat Nov 27, 2010 3:46 pm

Re: VIIRS second image layer speckled

Post by hproe »

Hi Rick -

I can confirm that reselecting the region works. However, this workaround is far from being satisfactory, as you are just left with having to draw the green box. Because no digital information of the subset is provided (like rthorugh Satellite>Imagery), there is no way to reproduce exactly the same sub-area. I hope the bug-fixing will be promoted to high priority.

BTW why do we not get something like the 'Advanced' tab also for VIIRS?

cheers, HP
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Rick
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Joined: Fri Jan 16, 2009 8:20 pm

Re: VIIRS second image layer speckled

Post by Rick »

Hi HP,

Making the selection process the same for all choosers is one of our goals.

Rick
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