Two new spatial data resources from US Census Bureau

Two new spatial data resources from US Census Bureau:

1)  New Version of TIGERweb

The U.S. Census Bureau has released a new version of TIGERweb, a Web-based map viewer from the agency’s Topologically Integrated Geographic Encoding and Referencing System (TIGER) database.

TIGERweb allows users to view and query census geographic areas and features such as roads, railroads, rivers, lakes and other larger bodies of water. It currently displays boundaries, names and codes for 2010 Census legal and statistical geographic areas, such as counties, cities, towns and townships, census tracts and urban areas. In addition, TIGERweb contains population and housing unit counts from the 2010 Census for each of the geographic areas.

To access TIGERweb, go to: <http://tigerweb.geo.census.gov>.

In addition to the TIGERweb viewer, the TIGER data also is available as a Web service via the Open Geospatial Consortium Web Map Service standard. Users who have a client that supports the Web Map Service standard may access the TIGERweb service at <http://tigerweb.geo.census.gov/ArcGIS/services/tigerWMS/MapServer/WMSServer>.

Joseph’s reflection:  You can obtain better quick choropleth mapping of census data from ArcGIS Online (www.arcgis.com), because the population and housing data on this site are quite limited.  So why would you use the above?  Sometimes  you need the actual block numbers (i.e. block 101, 102, etc), block group numbers, and census tract numbers, so that you can match the numbers with the tabular data.  In that case, the above service can be quite valuable.

2)  The US Census Bureau has posted 2010 block-level shapefiles by state with population and housing counts via FTP.

These shapefiles were created for a special project so they do not contain all of the attributes of the TIGER/Line Shapefiles but contain the information necessary to identify the census blocks.

An explanation and link to the data (the little tiny ‘ftp’ hyperlink) can be found here:

http://www.census.gov/geo/www/tiger/tgrshp2010/pophu.html

The link to the data (the tiny ftp hypertext) is here:

ftp://ftp2.census.gov/geo/tiger/TIGER2010BLKPOPHU/

Warning from Joseph Kerski:  These are large files!  But they might be useful, because block level data is not easy to obtain.

–Joseph Kerski

Shining a torch on location privacy

A couple of weeks ago the Olympic Torch was paraded through the village where I live.  In eager anticipation of the event, a couple of elderly neighbours, keen to get the best vantage point, asked if I knew which route the torch would be taken along. Deciding that a map was probably the best way to show this, I cranked up my iPad and opened up a map viewer.  The reaction from both neighbours on seeing their respective houses and surrounds in glorious Technicolor courtesy of some recent satellite imagery went something along the lines of …. ‘Oh look there’s my house … hey wait a minute that’s an invasion of privacy, I didn’t say they could photograph it’.

Trying my best to allay their fears about any perceived intrusion, arguing that the information was being put to many good uses, which by the way included helping us find the best place to see the torch, I couldn’t help thinking their reaction was not uncommon for their generation – immediately suspicious and wary of the implications. By contrast, younger generations are growing up today in a world where having easy access to this level of detailed location information is taken for granted. Not being able to see your house on Google Street View is simply ‘pre-historic’.

Location privacy is an issue we discuss in the book. Just what rights do individuals have now with pervasive street view imagery and video surveillance cameras on almost every street corner?  In response to a number of lawsuits from disgruntled individuals and private businesses, Google have argued that “complete privacy”  no longer exists in this age of satellites and high-resolution imagery, although they have made some concessions in the form face and licence plate blurring to protect unsuspecting passers-by and residents. The technology to capture, record and manipulate location information continues to develop apace;  just what legislation will be required to govern the use of that information is still being debated and it is a discussion that will continue for years.  It’s not the data that are the problem, it’s what some people choose to do with them that’s the issue.

The GIS Guide to Public Domain Data explains sources and quality of spatial data

This week sees the publication of The GIS Guide to Public Domain Data.  Available in both hard copy and as an e-book, the guide provides GIS users with detailed information about the sources and quality of spatial data available in the public domain and the policies that govern its use.

When co-author Joseph Kerski and I started this project, the open data revolution was well under way. Many individuals and organisations were advocating for improved access, preferably at no cost, to the vast reserves of spatial data collected by governments and organisations at local, regional, national, and international levels. At the same time, recent technological innovations, such as crowd sourcing and cloud computing, were also having a major impact on how people access, collect and work with spatial data.

Together these technical and organisational changes have had, and will continue to have, a significant influence on the availability of data in the public domain.