Proj4string for NASA GPW v3 and Blue Marble world city light map?

The specific projection information is contained within the raster
datasets you download, in the related ASCII, Bil or GRID file. The
metadata you see on that page is just a human readable representation of
the data coverage, not intended to directly map to the full spatial
reference.

--
Shaun Walbridge
GIS Developer




On 5/7/15, 5:15 AM, "Ziyu Ma" <paul.ziyu.ma at gmail.com> wrote:

Dear all,

I was working with a project concerning human population, using data from
the Population Density Grid, version 3.

I have hard time understanding the spatial reference from this metadata
page:

http://sedac.ciesin.columbia.edu/data/set/gpw-v3-population-density/metada

ta

Can I translate this into a proj4string so that I can use it as a CRS in
R?

Also, just out of curiosity, what it the spatial reference for NASA's Blue
Marble maps, like the famous world city light map? Can I also use a
proj4string to describe it?

Thank you very much.

Cheers,
Ma

Ziyu Ma
PhD Student
Ecoinformatics & Biodiversity,
Department of Bioscience, Aarhus University
Ny Munkegade 114, DK-8000 Aarhus C, Denmark

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