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VIIRS second image layer speckled

Posted: Fri Sep 25, 2015 9:10 am
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

Re: VIIRS second image layer speckled

Posted: Mon Sep 28, 2015 5:33 pm
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

Re: VIIRS second image layer speckled

Posted: Wed Sep 30, 2015 1:07 pm
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

Re: VIIRS second image layer speckled

Posted: Wed Sep 30, 2015 4:09 pm
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

Re: VIIRS second image layer speckled

Posted: Wed Sep 30, 2015 6:39 pm
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

Re: VIIRS second image layer speckled

Posted: Fri Oct 02, 2015 3:09 pm
by Rick
Hi HP,

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

Rick