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chrisvwn / Rnightlights

R package to extract data from satellite nightlights.
GNU General Public License v3.0
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Moonlight, fires, and other natural sources of light #26

Closed nreguera closed 5 years ago

nreguera commented 5 years ago

Hello Chris,

I am wondering if the data available through the package could be linked to the corrections that Miguel Román and his team did over the VIIRS data (you can read about this here [https://earthobservatory.nasa.gov/images/90008/night-light-maps-open-up-new-applications]).

Thanks

chrisvwn commented 5 years ago

Hi Natxo,

This is one of the future features of the package. It currently does not remove the known lights sources. For many countries it won't be a problem but countries with oil drilling, wildfires, volcanoes will be affected. However, if I remember well, there is one of the nightlights datasets that already has that correction applied. Let me do a check and get back to you.

chrisvwn commented 5 years ago

Hi Natxo,

Sorry for taking so long to get back to you.

So, I was not quite correct. The nightlights datasets that have fire and ephemeral lights removed are in the VIIRS.Y dataset. Flares, fires, etc averaged annually are used to remove these lights. None of the VIIRS.M files has this.

Please see this page for details on the various VIIRS files and what they contain (https://www.ngdc.noaa.gov/eog/viirs/download_dnb_composites.html). You can choose the appropriate file to use in the package by setting the pkgOptions("configName.VIIRS.D/M/Y") option. Run ?Rnightlights::pkgOptions to see the corresponding options and available values.

For more information on fires, flares, etc you might want to look at this page: https://ngdc.noaa.gov/eog/viirs/download_viirs_fire.html. This document gives some procedure to process nightlights including gas flare removal: http://darrylmcleod.com/wp-content/uploads/2016/06/Night-Lights-and-ArcGIS-A-Brief-Guide.pdf

I will be adding this option in a future release.

nreguera commented 5 years ago

Hello Chris,

Thank you for the information. I will be attentive to the release.

effi425xiao commented 4 years ago

Hi Chris, I am only interested in Gas Flares and how you get only these signals removed, do you have a layer for that? Xiao

chrisvwn commented 4 years ago

Hi,

I do not have the layer for VIIRS. For OLS you can get the polygons here:

https://ngdc.noaa.gov/eog/interest/gas_flares_countries_shapefiles.html

However, I am not sure about how up-to-date they are.

effi425xiao commented 4 years ago

Thanks for the reply, I checked this data yesterday, it didn't cover the flares I could see in some areas. I am curious if you know of the processing code on VNF, for gas flare? Xiao

On Thu, Aug 27, 2020 at 2:29 AM Chris Njuguna notifications@github.com wrote:

Hi,

I do not have the layer for VIIRS. For OLS you can get the polygons here:

https://ngdc.noaa.gov/eog/interest/gas_flares_countries_shapefiles.html

However, I am not sure about how up-to-date they are.

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chrisvwn commented 4 years ago

Unfortunately, no. This is one of the tasks I need to complete to put this package back up on CRAN. But haven't had the time as of yet.