|
|
|
|
|
|
Plot Circles on MapThis program can be used to generate up to two concentric circles which will be overlaid on a map of the United States or a portion thereof. The map and circle center is determined from latitude and longitude coordinates given degrees minutes seconds or decomal degrees. With some preliminary work on your part, these maps can be used to:
The generated maps are returned as GIF files into IFRAMES. Most newer browsers support the IFRAME HTML tag, some better than others. Depending on which browser you use, you may have to (1) right-click and save the map image as "your-filename.gif" to your hard drive, the open the file to print it (Internet Explorer), (2) print the image via File | Print (Opera), (3) or print the HTML page (Firefox)..Other browsers may react differently, so some experimentation with printing may be needed. It must be noted at the outset that this program will not generate actual service or interfering contours for radio stations. Actual signal strength contours for FM or TV stations are affected by the terrain in a given direction, as well as the irectional pattern (where used) of the broadcast station. Nevertheless, by using circles in lieu of contours, a particular contour of interest may be approximately located. The circle data will be close to the nondirectional contour data over flat terrain, but may be less so in mountainous terrain. Also, actual coverage will usually be less than predicted here if a directional antenna is in use. Please keep these facts in mind when reviewing the map plots generated by this program. This program employs the Census Bureau's Tiger Mapping Service to generate the map backgrounds.Because the Tiger Map servers are very busy, and due to the large size of the files sent over (over 360 points per circle), it may taje a minute or two to generate a map. We suggest that you look at the information available at the Census Bureau's Tiger Mapping Service (particularly the FAQ page), to get an idea of the capabilities and limitations of this program. Please note that not all options available for the Tiger maps have been implemented in the FCC's circle plot program. After sending the initial data, you will have the option of modifying the data to recenter oe resize the map. The initial circles will be scaled to fit the map, if no specific map size is entered; Before using this program, please confirm the cache on your browser is set to verify documents every time. Resources you may want to refer to before creating a map include:
Comments and suggestions may be directed to Dale Bickel, dale.bickel@fcc.gov.
|
This page is located at http://www.fcc.gov/fcc-bin/audio/circleplot.html.
This page and the Circleplot function were revised January 19, 2009.
FCC Home | | | Search | | | Updates | | | E-Filing | | | Initiatives | | | For Consumers | | | Find People |
Federal Communications Commission 445 12th Street SW Washington, DC 20554 More FCC Contact Information... |
|
|