VIIRS Imagery

[kbedka1]

SUCCESS!!! The problems must have been caused by an incompatible VIIRS plugin

[kbedka1]

OK, now onto my true goal, trying this with 2 granules appended together. In the data chooser, I highlighted 2 adjacent VIIRS granules. The preview image shows the data from both granules, but swathToGrid does not work. I tried only selecting a portion of the merged granules with a size equivalent to one granule, res=800, mode=1. I get the grey bar at the bottom of the wireframe box again. See attached screenshots.

BTW, why did you suggest I use the "Under Development" NPP data chooser rather than the General -> Files/Directories Data Type: Suomi NPP data source?

[kbedka1]

It also appears that numbers less than res: 800 do not work. I'd assume "800" sets up a grid with a resolution of 800 meters? The data I have is 375 m so I'd prefer to preserve the highest resolution data if possible. Is there any way I can do this with swathToGrid?

[tommy.jasmin]

OK, now onto my true goal, trying this with 2 granules appended together. In the data chooser, I highlighted 2 adjacent VIIRS granules. The preview image shows the data from both granules, but swathToGrid does not work. I tried only selecting a portion of the merged granules with a size equivalent to one granule, res=800, mode=1. I get the grey bar at the bottom of the wireframe box again. See attached screenshots.

BTW, why did you suggest I use the "Under Development" NPP data chooser rather than the General -> Files/Directories Data Type: Suomi NPP data source?

Kris :

1. Yes, you SHOULD be able to work with multiple adjacent granules. If this is not working I will speak to Tom Rink about it, he wrote that plug-in. I am not even sure what the mode parameter means or does.

2. The reason using the Suomi NPP Chooser is preferable to simply loading a file is because this chooser examines the directory contents and
only allows you to select valid, displayable data. It does some initial inspection to "make sure all the pieces are there and make sense". Also, if you try to load/aggregate multiple granules it ensures they really are contiguous, a necessary step to give you a single piece of data to work with.

[tommy.jasmin]

It also appears that numbers less than res: 800 do not work. I'd assume "800" sets up a grid with a resolution of 800 meters? The data I have is 375 m so I'd prefer to preserve the highest resolution data if possible. Is there any way I can do this with swathToGrid?

Kris - I should probably try to locate, install, and try this plug-in myself before commenting, but to address the question of working with your data at max spatial resolution, any time you subset from a preview window that data will be displayed at full spatial res, and yes for VIIRS I-Band that is 375 m.

[joleenf]

Hi,

Is there information about using this formula in the User's Guide? I have tried to find information using the search and have failed to find any. It would be helpful to understand that

1.) Displaying NPP data without selecting a subset will display data at a reduced resolution
2.) The meaning of mode and res. when using the swathToGrid formula, and that the default for res is coarser than the raw data
3.) The VIIRS RGB formula automatically uses swathToGrid and removes the blindfolding?
4.) Selection of multiple granules, should be done in the Data Chooser tab to eliminate gaps between granules when they are displayed.

Maybe some of this is already outlined in the user's guide, but I have failed to find it.

Thanks,
Joleen

[bobc]

Hi Joleen -

The information you listed out about the Suomi NPP chooser is not currently in the User's Guide because the chooser is still in the Under Development tree in the Data Sources tab of the Data Explorer. Once this chooser is in a more stable state and it is moved out of the Under Development tree, documentation will be added to the User's Guide. The formulas from the VIIRS Formulas plugin aren't currently documented either in the User's Guide because they rely on the Under Development chooser. Once the Suomi NPP chooser is out of Under Development we may move these formulas out of a plugin, and they will then be documented in the User's Guide.

Currently, the documentation for the Suomi NPP chooser is written up in the Under Development tree of the forums in a post called NPP Chooser:
viewtopic.php?f=13&t=808

The most recent post is for McIDAS-V version 1.3. I will write one up for 1.4 shortly that includes the added functionality of working with EDRs.

Thanks -
Bob Carp

[joleenf]

Could you consider adding a link to this post if someone searches the user's guide for help. It could be simple like

"The Suomi NPP Chooser is still under development, therefore the current help is limited to the following forum post:
viewtopic.php?f=13&t=808"

This will give the user some assistance rather than leaving them to wonder why there is no information. Right now, the default lower resolution and some of the little tricks needed to display Suomi NPP data well may lead new users to believe that McIDAS-V cannot display this format well. This is contrary to the truth. Improving that first impression is important.

Joleen

[bobc]

Hi Joleen -

I brought up your suggestion of linking to the actual forum post for Suomi NPP in the User's Guide, and for right now we are deciding to not do that. However, we are currently working on a new search feature that will not only search the User's Guide, but it will also search the forums and the tutorials. Once this feature is available, it will be much easier for users to find information they may be looking for that might not be in the User's Guide.

Thanks again for your suggestions -
Bob