The U.S. Census Grids provide raster data sets that include not only population and housing counts, but a wide variety of socioeconomic characteristics. These gridded data sets transform irregularly shaped census block and block group boundaries into a regular surface – a raster grid – for faster and easier analysis.
M. Hampe, M. Sester, and L. Harrie. ISPRS Congrese, volume XXXV of International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences, page 135-140. Lund University, Dept of Physical Geography and Ecosystem Science, (2004)
S. Sun, S. Prasher, and X. Zhou. Conceptual Modeling for Advanced Application Domains, volume 3289 of Lecture Notes in Computer Science, Springer Berlin Heidelberg, (2004)