October 13, 2010 - 3:07 pm
Michael Byrne | Geospatial Information Officer

[[wysiwyg_imageupload:158:height=100,width=70]]Based on your comments and suggestions, we've just released updates to our FCC.gov/developer API's. In particular we have made two enhancements: one to help navigate the complexities of census geography, and one that's purely stylistic.

Census geography changes, while small or obscure, can be significant. A tiny change in a census boundary can mean that a rate based calculation includes a completely different denominator for population or demographic value. These changes, if not watched for carefully can be significant to the results of querying large federal databases.

To assist the community of developers building off FCC tools, we'll try and point out these small but significant changes when we see them.

The biggest change between 2000 census boundaries and 2009 census boundaries was the addition of a sub identifier to the smallest unit of boundary, the block. This addition allows for finer resolution to the map base. However, because of other changes like population growth, demographic switches, and land use changes, the external boundaries of the block boundaries have also changed.

In order to keep up with these issues, we are supplementing our FCC Census Block API with the ability to query for the current year as well as previous years. From now on, the current (e.g. 2009) year search will be the normal REST query on the documentation page like this;


To gain access to a previous year, all you need to do is insert the year in the url like this;


The stylistic change we made removes the @ symbol from the return, moving to a natural JSON notation to allow for better integration with some client libraries.

These changes are live now. Here's a preview of /Developer updates coming down the pipeline:

See below for a more complete description of the most recent changes. Happy Coding, and don't forget to let us know what kind of applications you are building with FCC Developer tools.

1) Changed JSON output to follow the natural convention for Block and Speed Test APIs. This changes the output from:

{"@executionTime":"0.071","@status":"OK","Block":{"@FIPS":"060470009012065"}, "County":{"@name":"Merced","@FIPS":"06047"},



Please note that the @ symbol has been removed from the attributes within a JSON object. This should make it easier for these data structures to be consumed from some libraries such as jQuery.

2) Added version year for census block geospatial search

There is an additional option to request Census Block data for Census 2000. The original call will return the most recent Census Block information (2009)

Original query for Census information (current information)


<Response executionTime="0.054" status="OK">
<Block FIPS="060470009012065B"/>
<County name="Merced" FIPS="06047"/>
<State name="California" code="CA" FIPS="06"/>

Census 2000 block information


<Response executionTime="0.052" status="OK">
<Block FIPS="060470009012065"/>
<County name="Merced" FIPS="06047"/>
<State name="California" code="CA" FIPS="06"/>

3) Fixed the following bug

When passing wrong coordinate information (i.e. outside of the U.S. and territories) the response returned a badly formed XML if no format for the response type was specified.