4.27.2006

More on Landscan

I said yesterday that Landscan and CIESIN incorporate additional (ancillary) population estimates. In many cases census data are too coarse a resolution (blocks in the US) or out of date. What data does Landscan incorporate?

Their most recent data is for 2004. It includes some high-resolution land cover data from the National Geospatial Intelligence Agency (NGA), administrative boundaries, and some satellite imagery I'm not familiar with (anyone? what is NGA's VMAP-1 or CIB), plus some actual imagery from the space shuttle on topography (SRTM) which is pretty cool. For more see here.

Other data include roads (TIGER in the US); slope angle (the Digital Terrain elevation [DTED] from the NGA predecessor, NIMA); land cover imagery in this case USGS Global Land Cover Characteristics (GLCC)--again I'm not familiar with this, if anybody has any info please leave in comments--is it any good, are there any better ones for the SE USA?

Also populated places (the VMAP data); nighttime lights; and census data being allocated to cells by a so-called "smart" interpolation routine (if roads are in the cell, allocate more population?).

Resolution is apparently 30" by 30" or about 1 square kilometer, hence much better than CIESIN which is 2.5' at best.

Now I need to know how to apply the density grid. There's no documentation on the Landscan site and emails to their office go unanswered.

1 comment:

gis girl said...

you can find answers to most of these questions at http://www.ornl.gov/sci/landscan/

There is a FAQs page with some of the answers and an email for questions not included in the FAQ section.