[GRASS-user] NASA nightlights qn

GRASS GRASS user
1

Dear GRASS users,

If anyone has experience using the NASA nightlights datasets, I would appreciate a conversation. I am thinking of using it to track city level growth in spatial boundaries, demographics etc for Indian cities, but would like to discuss with anyone more experienced with the datasets first (resolution, saturation effects etc, inter-calibration).

I am first thinking of trying to use this to spatiotemporaly interpolate ward-scale population between (10 yr) interval census years. That is, if i have ward-scale (sub-city)population, can i use nightlights to interpolate ward-scale population growth for each year in-between the census years…

I believe there is an incomplete add-on regarding calibration between datasets?

Also, could anyone sugest a color style in GRASS that would work well?

Thanks, and a merry christmas and happy holidays!

Vishal

···

Vishal K. Mehta, PhD
Sr. Scientist
Stockholm Environment Institute - US
133 D St Suite F
Davis CA 95616
www.sei-us.org

2

* Vishal Mehta <vishalm1975@gmail.com> [2015-12-23 09:03:06 -0800]:

Dear GRASS users,

If anyone has experience using the NASA nightlights datasets, I would
appreciate a conversation. I am thinking of using it to track city level
growth in spatial boundaries, demographics etc for Indian cities, but would
like to discuss with anyone more experienced with the datasets first
(resolution, saturation effects etc, inter-calibration).

I know at least two students who work with night-lights for ther
Master's Thesis. I'll forward them this e-mail.

If it's worth anything, a related add-on:

<https://trac.osgeo.org/grass/browser/grass-addons/grass7/imagery/i.nightlights.intercalibration?order=name&gt;

Inter-calibration has been an important subject for the DMSP OLS
instruments. Would be nice to learn more about newer developments, and,
if possible, expand the addon.

I am first thinking of trying to use this to spatiotemporaly interpolate
ward-scale population between (10 yr) interval census years. That is, if i
have ward-scale (sub-city)population, can i use nightlights to interpolate
ward-scale population growth for each year in-between the census years..

I believe there is an incomplete add-on regarding calibration between
datasets?

The add-on, given we mean the same one, is complete in the sense that the three
main models, integrated there-in, do what they intend to do. Up until someone
identifies any errors :-).

Any kind of assistance would, then, be more than welcome.

Thanks, Nikos

Also, could anyone sugest a color style in GRASS that would work well?

Thanks, and a merry christmas and happy holidays!
Vishal

3

Vishal Mehta:

> I believe there is an incomplete add-on regarding calibration between
> datasets?

Nikos Alexandris:

The add-on, given we mean the same one, is complete in the sense that the three
main models, integrated there-in, do what they intend to do. Up until someone
identifies any errors :-).

See also:

https://gitlab.com/NikosAlexandris/i.nightlights.intercalibration/blob/master/documentation_R.pdf

If I remember well, the only real difference should be the lack of the pdf file
(in grass-addons/grass7).

Nikos

4

Thanks Nikos,

Yes i was talking about the same add-on as you developed and pointed to. I’ll look into the links you sent and get back.

Also, am happy to talk with the students you mentioned. Am open to developing some kind of MS project/work study program as well, to take this forward.

Thank you again and best wishes for the new year ahead,

Vishal

···

On Wed, Dec 23, 2015 at 10:55 AM, Nikos Alexandris <nik@nikosalexandris.net> wrote:

Vishal Mehta:

I believe there is an incomplete add-on regarding calibration between
datasets?

Nikos Alexandris:

The add-on, given we mean the same one, is complete in the sense that the three
main models, integrated there-in, do what they intend to do. Up until someone
identifies any errors :-).

See also:

https://gitlab.com/NikosAlexandris/i.nightlights.intercalibration/blob/master/documentation_R.pdf

If I remember well, the only real difference should be the lack of the pdf file
(in grass-addons/grass7).

Nikos

–

Vishal K. Mehta, PhD
Scientist
Stockholm Environment Institute - US
133 D St Suite F
Davis CA 95616
www.sei-us.org