For the Nationwide Public Radio Coverage Under-Service and FM Translator Spectrum Vulnerability Study, NPR Labs calculated coverage and demographic information for more than 1500 public radiotransmitters.  The demographic data we collected represented over 150 fields drawn from censuses in 1990, 2000, and projected data for 2007.  The resulting database included well over 350,000 data points – far more than a physical document could hold in any accessible format.  We created the NPR Labs Online Viewing Application (NOVA – located at http://www.nprlabs.org/nova/) to address this concern.

NOVA allows the user access to this wealth of data in smaller, more digestible chunks.  Users navigate through a Google Maps interface customized with a layer of radio transmitters and coverage profiles.  Where the physical document presents selected demographics and coverage information based on state composites, the online interface allows users access to all of the data fields we collected on a station-by-station basis.

Interface

The interface mimics a typical GIS interface in the following ways:

1. Users are presented with a dynamic list of public radio stations that appear in the current viewframe
2. Users can turn multiple individual station coverages on and off, visually examining the overlapping areas
3. When the user selects a station, all of the demographic information relevant to that individual station appears in a window below the map screen.

One limitation of the online interface is its lack of output.  Google’s Terms of Use prevented us from including a feature allowing you to output the map display from the screen, so if you need to refer to maps you’ve created online, you’ll have to go in and recreate them.  Also of note – NOVA is optimized for a screen resolution of 1440 x 900, although different resolutions will have the same functionality.

A visual description of the interface provides a better explanation of its features:

Demographics

Demographic information was collected for over 150 different fields in censuses collected in 1990, 2000, and projected information from 2007. Because the data collected over each census period changes, some mapping of census fields was required to make a comparable dataset. Listed below are all fields collected, and their mappings between different collection periods. Cells colored in gray correspond to information not collected in that specific census year - the interactive demograhpics table will label these fields as '-1'.