- What is the input data and methodology that supports the development of the LandScan data?
- What software is required to read the data files?
- What is a WMS and a WCS?
- Does East View's web application work with Google Maps?
- Is LandScan available for population studies outside the US?
- Is a data dictionary of the datasets available for research use?
- What is the Projection/Spheroid of the LandScan data?
- What are the LandScan Dataset values?
- In the population database table, what does the field “Value” contain?
- In the population database table, what does the field “Count” mean?
- Why do some users have access to previous versions of LandScan while others can only register for the current release of LandScan?
- Are previous versions of the LandScan Global Population Datasets available?
- Can I download the input datasets used to develop the LandScan Dataset?
- Do the LandScan Global Population Datasets represent population count or population density?
- What data formats are used?
- What attributes are provided for data layers that are geospatially referenced?
- Can I convert the LandScan Grid file to a shapefile?
- How do I calculate population density?
- I am having trouble logging on to the LandScan data download page. Can you help?
- How do I cite LandScan when I use the data in my publications?
- Can I use multiple years of LandScan for cross year analysis?
- Go to page: http://www.ornl.gov/sci/landscan/landscan_documentation.shtml
What software is required to read the data files?
If you are accessing LandScan through East View's web application, no additional software is needed, only a web browser. All major web browsers are supported. Best performing browsers for web mapping applications include Mozilla Firefox, Google Chrome and IE9+.
The data is provided in a hard copy format which is digestible in any GIS software that allows the user to import ESRI GRID-formatted data. The WMS and WCS are links to the data hosted on East View Geospatial’s servers for organization-wide 24/7 access and can be used with most current GIS software. The data files are also provided in a Raster Binary format. Almost any programming language can read this file directly. See also “What data formats are used?” below.
The data files are also provided in the ESRI Raster Binary format. Almost any programming language can read this file directly. See also “What data formats are used?” below.
What is a WMS and a WCS?
A WMS and WCS are specifications that were developed by the Open Geospatial Consortium in 1999 for publishing of GIS data over the web. These protocols allow for access of GIS data over the Internet.
A Web Map Service (WMS) is a standard protocol for serving georeferenced map images over the Internet (http link) that are generated by a map server using data from a GIS database. A WMS is similar to Bing Maps or Google Earth where the user can view the data and implement simple spatial queries on the underlying data. No extraction or processing of the data is available through a WMS.
Web Coverage Service (WCS) provides an interface allowing requests for geographical coverages across the web using platform-independent calls. The coverages are objects (or images) in a geographical area, whereas the WMS interface or online mapping portals like Google Maps return only an image, which end-users cannot edit or spatially analyze. A WCS is essentially a live link to the data which allows you to symbolize and run processing on the data as if it was stored on your local hard drive. A WCS allows the users to extract the data and keep it locally for their own use.
Does East View's web application work with Google Maps?
No, it does not.
Is LandScan available for population studies outside the US?
Yes, we have global data as well as sets by world regions and individual countries.
Is a data dictionary of the datasets available for research use?
Included with the data is ORNL produced metadata and various readme files which explain the data and updates.
What is the Projection/Spheroid of the LandScan data?
The LandScan Dataset is not projected, but can be used as a “Geographic” projection with various GIS software packages (e.g., ERDAS and ESRI). The data are referenced by latitude/longitude (WGS84) coordinates.
What are the LandScan Dataset values?
The dataset values are people per cell.
In the population database table, what does the field “Value” contain?
The "Value" field in the database table contains the number of people per cell. This is a population count per cell, not a population density.
In the population database table, what does the field “Count” mean?
The “Count” field in the database table contains the number of cells that have the same population count as the cell of interest.
Why do some users have access to previous versions of LandScan while others can only register for the current release of LandScan?
When a new version of the LandScan dataset is available, the previous version is archived. To get access to the most up-to-date dataset, users will need to purchase to new version to access. The previous years are available through East View as an archive product and include the datasets back to the year 2000 edition.
Are previous versions of the LandScan Global Population Datasets available?
Yes, historical LandScan Global datasets, dating from 2000 to 2010, are now available through an archive purchase. The raw population data can be used in GIS applications and the WebApp will provide easy access for non-GIS users to view and analyze the data online. Contact LandScan@eastview.com for more information.
Can I download the input datasets used to develop the LandScan Dataset?
Datasets used in the development of the LandScan Global Population Dataset are not available. During the development of the population database Oak Ridge National Laboratory uses datasets that are provided by many sources and for which there are no redistribution rights.
Do the LandScan Global Population Datasets represent population count or population density?
The LandScan datasets represent population count.
What data formats are used?
ESRI grid format. The archive contains grids for the world and each of the six continents, excluding Antarctica. Each of the archive files contains two folders, an ArcInfo GRID folder and an INFO folder. Both folders must be extracted from the archive file into one new folder.
ESRI binary format. The archive contains contains raster binary data for the world and a rich text formatted file that describes the binary format. The binary raster file format is a simple format that can be used to transfer raster data among various applications. Almost any programming language can read this file directly.
For both formats, downloaded files need to be uncompressed using a standard Zip utility (e.g., WinZip, PKZIP, etc.) before they can be imported to GIS or other software. Users should expect a substantial increase in the size of downloaded data after uncompression. For additional information see the ReadMe file for 2008.
What attributes are provided for data layers that are geospatially referenced?
The dataset includes four layers:
- country level demographic data
- 1st level admin demographic data
- pixel (1km x 1km) level population data
- an area calculation layer
The country and 1st level admin level data include demographic data such as age, gender and age by gender population breakdowns. The pixel level data contains a total ambient population value for each cell. All data is georeferenced in the geographic projection WGS 1984. Included with the data is a toolbox for use with ESRI’s spatial analyst extension (helpful but not necessary) as well as pre-symbolized layer files to use for symbolizing the data.
Can I convert the LandScan Grid file to a shapefile?
We do not recommend converting the GRID data into a shapefile containing polygons because “people” are lost during the conversion. If users must convert the data from grid format to feature format, we recommend converting to a point file. This way each point represents the cell total as maintained in the GRID format.
How do I calculate population density?
The links below contain instructions for calculating population density:
I am having trouble logging on to the LandScan data download page. Can you help?
For users of the East View online version of LandScan, contact LandScan@eastview.com. If you are a U.S. Government user, contact firstname.lastname@example.org and/or email@example.com.
How do I cite LandScan when I use the data in my publications?
This product was made utilizing the LandScan (insert dataset year)™ High Resolution global Population Data Set copyrighted by UT-Battelle, LLC, operator of Oak Ridge National Laboratory under Contract No. DE-AC05-00OR22725 with the United States Department of Energy. The United States Government has certain rights in this Data Set. Neither UT-BATTELLE, LLC NOR THE UNITED STATES DEPARTMENT OF ENERGY, NOR ANY OF THEIR EMPLOYEES, MAKES ANY WARRANTY, EXPRESS OR IMPLIED, OR ASSUMES ANY LEGAL LIABILITY OR RESPONSIBILITY FOR THE ACCURACY, COMPLETENESS, OR USEFULNESS OF THE DATA SET.
Can I use multiple years of LandScan for cross year analysis?
Although previous year datasets are available, researchers should be aware that the data should not be used as a change detection or migration tool. Input data sets are constantly improving which in turn cause changes in the population distribution, so a cell by cell comparison between LandScan database releases will not be an accurate assessment of the data.
For instance, higher-resolution data depicting populated places (towns or villages) may be loaded into this year's version, which did not exist in the digital representation of the area at a coarser scale. Of course the people were there all along, but may just "show up" in the latest version of the distribution.
In other cases there may be a more refined administrative boundary file used as a population control total boundary. These new boundaries may cause the population distribution within them to shift from an earlier version with a coarser boundary.
In some cases actual census counts associated with an administrative area may have been transposed with a nearby administrative area somewhere in the process. Correcting these types of errors also cause the population distribution to shift.
For these reasons users should be aware that the comparisons between LandScan versions will not be accurate ("migrations" are not taking place).
Contact LandScan@eastview.com if you have additional questions.