by Kurt E. DeSoto

Many FCC applications require practitioners to specify the geographic coordinates associated with the site that is the subject of their filings. For example, an application on FCC Form 601 seeking authority to construct an additional transmitter location will require coordinates to be specified on Schedule D. Registration of an antenna structure or tower will require the filer to provide the latitude and longitude on Item 24 of FCC Form 854. A filing for a modification to an FM broadcast station must indicate the coordinates on Schedule III-B of FCC Form 301. Even a request for special temporary authority to test prototype electronic devices may require the latitude and longitude in Item 5 of FCC Form 442.

Practitioners should ensure that the coordinates provided to the FCC are accurate for many reasons, but a particularly important one is to protect against interference either to or from the proposed location. When FCC or third-party processors conduct interference analyses, they typically use coordinates rather than street addresses. If an application (and thus the resulting license) specifies the wrong coordinates, it is possible that the agency or later applicants might not afford the licensee appropriate protection. Moreover, it may be difficult to amend the license after it is granted, especially if using corrected coordinates results in predicted interference to another operator. Indeed, in a number of cases licensees that used incorrect coordinates were required to accord protection to co-channel operators that were authorized much later than the original licensees.

Usually a call to the responsible engineer is enough to get the correct coordinates. The engineer will likely have on file coordinates determined by a licensed, professional surveyor-the preferred method to obtain coordinates. If not, the engineer might dispatch to the site field personnel equipped with a professional-grade GPS receiver to obtain the coordinates. Differential GPS provides the most accurate results.

But what if an engineer is unavailable or does not have the means to get the coordinates? Or what if an engineer (or other client personnel) has the coordinates but has not been able to verify their accuracy? Even when you do have the coordinates, there is often a need to convert them from the older reference based on the North American Datum of 1927 (NAD27) to the newer 1983 reference (NAD83) or from degrees/minutes/seconds to decimal degrees.

Fortunately, there are several free Internet sites that practitioners can use to determine, verify or convert coordinates for informal purposes. As a substitute, there are a variety of inexpensive software programs that provide coordinate information (I would recommend DeLorme's "Street Atlas USA"). Of course, it bears emphasizing that the preferred method is to rely on professional surveys, especially for formal or critical filings, such as tower sitings.

If you have the correct street address for a location, you can obtain coordinates and verify them over the Internet by taking the following steps:

Step One: Go to http://www.geocode.com/modules.php?name=TestDrive_Eagle, insert the street address in the fields shown and click on the "request" button. The site will display a map with an "X" or other marker to designate the location of the address. In addition, the coordinates will be provided in the World Geodetic System of 1984 format ("WGS-84"), which is similar to the NAD83 format. The coordinates will be provided in both degrees, minutes, and seconds (e.g., 38° 53' 05" N; 077° 01' 42" W) or their decimal degree equivalent (e.g., 38.884845; -77.028375).

Step Two: The FCC might require applicants to use NAD83 datum (which have superseded the NAD27 datum). If your geographic coordinates must be translated from NAD27 to NAD83 datum, log onto the National Geodetic Survey website at http://www.ngs.noaa.gov/cgi-bin/nadcon.prl and follow the instructions to convert the coordinates. The site will accept information in both decimal and non-decimal formats.

Step Three: Go to the U.S. Census Bureau's site located at http://tiger.census.gov/cgi-bin/mapbrowse-tbl to confirm that the coordinates are correct (note: this URL does not use the prefix "www"). Zoom in or out as appropriate to obtain the necessary level of detail to make this determination. You will need the coordinates in NAD83 decimal degrees, though, which can be obtained using the steps described above or by employing the following equation where either the Latitude or the Longitude equals: Degree + (Minutes/60) + (Seconds/3600).

If you only need to confirm the accuracy of coordinates given to you in a draft application or technical showing, skip to Step Three. I have done this on occasion when the coordinates I received appeared somewhat suspicious. For example, I recently discovered that the coordinates for a tower in Chicago were actually in the middle of Lake Michigan. I think the field personnel sent with a GPS receiver to the site went fishing instead. I hope we both made a great catch!

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Mr. DeSoto is an attorney at the law firm of Wiley Rein & Fielding LLP. He practices in the areas of wireless and wireline telecommunications, telephone company ratemaking, and equipment authorization. He previously worked in the FCC's Common Carrier Bureau.


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