I'm from the Census Bureau and I am always being asked for a way by which people who wish to analyze our data either across different geographic boundary definitions or over time wherein boundaries changed. It would be so awesome if you guys could open-source your algorithm so that we could share it with the world of folks who need something like this :)

If you want to use SEDAC WMS with openlayers.js, it would be nice to provide a (link to a ) working sample code like http://jsfiddle.net/F9pUs/ (which actually does not show the SEDAC layer)

Hi, I am trying to read the population density data in 2005 and 2015 in Matlab. I am using the following codes.

[pop, R] = geotiffread('gpw-v4-population-density_2005.tif');
figure
mapshow(pop, R);

The reference R looks normal, but the density matrix pop has huge negative numbers in each entry. I also tried to use Mathematica to read the file, and it also does not work. Could you provide us simple examples on how to access your tif file? Thanks!

I would love information on population density etc. from the most recent census. Is there a reason this is only the 2000 data?

Thank you for providing yours data and service.

I have two suggestion for your server configuration that can improve your WMS

1) Can you make the content available via HTTPS? (https://developer.mozilla.org/en-US/docs/Security/MixedContent/How_to_fix_website_with_mixed_content)

2) Can you adding CORS support to the server? (http://www.html5rocks.com/en/tutorials/cors/#toc-adding-cors-support-to-the-server)

Thank you for your kind cooperation.

Very large data-sets (e.g., global roads at ~200MB) are very difficult to download at one go when in poor/unreliable bandwidth areas. Suggest one or more of the following:
1. breakup data sets into smaller regional and/or country level chunks
2. allow downloads to resume after interruption
3. use distributed methods of serving data (p2p, torrents, etc) ... this will also reduce your server / bandwidth requirements!

Do you plan to provide your data layers as REST services?

on this page: http://sedac.ciesin.columbia.edu/data/set/gpw-v3-population-density/data-download
After I logged in, filled all the fields (region>global>Pop Density grid>grid>2.5'>2000), and hit "Download", nothing happens. I tried with Google Chrome and Mozilla Firefox.

jamesbajo@yahoo.com

I found large inconsistencies for population count in Tanzania between GPW 2010 and worldpop 2010 at the district level (2002 boundaries). It looks like GRUMP is more comparable, but it is difficult to compare as GRUMP is not available for 2010. Do you know the reason for the inconsistencies? and would you recommend GPW or GRUMP when calculating population at the district level? Finally, will GRUMP be available for later years in the near future?

Best,
Julie

On the URL http://sedac.ciesin.columbia.edu/maps/gallery/search/10 I sought information about the United States, in connection with my present research. By page 7 I realized the maps are largely sorted alphabetically by geographical location. Since I aim to see what's available, it appears that I have to click "next" another five dozen times in order to possibly reach the maps for USA. Is there a shortcut?

The map for the Hong Kong Urban Extent (GRUMP v1) is incorrect - it shows NO urban extent, and Hong Kong is very urban...
http://sedac.ciesin.columbia.edu/downloads/maps/grump-v1/grump-v1-urban-extents/hkgextents.png

Hi it's me Sneha :) I was visiting the GPW collections page and found a bug on http://sedac.ciesin.columbia.edu/data/collection/gpw-v4, towards the end of the last para on "To see the previous version of GPW, visit the GPWv3 data collection". The link to GPWv3 points to an alpha.sedac.ciesin page.

I am looking at the possibility of using the HII to understand anthropogenic impact on North American birds as a part of my graduate research. I noticed that the data available is for 1995-2004 and was wondering if 2005-14 is on the works. SO my questions are: 1. Are you working on HII 2005-14? and 2. If you are, will the data be publicly available? When? Thanks.

I thought I had a bad download, but the documentation shows a hole in N. Pakistan. This area is filled in VMAP, so it seems like that area could be filled. Is there a version of groads asia that includes this?

Hello,

I downloaded "Gridded Population of the World, Version 3 (GPWv3): Centroids". It is really terrific data! Bravo!

But I must say that I wasn't able to use correctly administrative level names: problems with diacritic symbols (like "ñ", "ç", "à" etc.).

I couldn't identify encoding of data (unicode, ISO8859-1, ?). So please could you give information about this encoding (inside metadata?).

Thanks in advance.
Michel (France)