Tips on Lat/Long

Tips on determining Latitude and Longitude

Here are some ideas on determining and double checking position data in latitude/longitude.

The location data is critical to the coordination. If you get it way wrong, the coordinator may not be able to proceed (for example, coordinates are OUTSIDE the state of Iowa). If you are off by miles, your coordination will be invalid, and the separation spacing between co-channel and adjacent channel stations will be invalid.

Its worth taking the time to get it right, and double check your answers.

There’s various ways to determine latitude and longitude:

  • GPS receiver (you may have one in your phone)
  • Maps: topographical maps are available, or can often be found in libraries
  • On-line maps: Google, Yahoo, and others have online map tools that can provide the latitude and longitude information.
  • If your station will be located at a site already registered with the FAA and FCC, you can look up data on that facility on the FCC’s “TOWAIR” website. The Antenna Structure Registration Number can be entered at the FCC web site, which will give you the exact coordinates. If you don’t know the ASR Number, you can use the FCC site to search an area by zip code or general lat/long.

The coordination form expects position coordinates in degrees, minutes and seconds.
Some tools work with decimal degress, while others have degrees, minutes and seconds. Scientific calculators often have a feature to convert between them. The FCC has an online resource to convert between both formats.

Once you have the coordinates, you may want to double check your work via another means. For example, if you went to the site with a GPS receiver, you might go to Google Maps, enter the coordinates, and see if the tool puts its position marker on its map where you expected.

Another Sanity Check:

Iowa’s borders are roughly inside the following ranges:

40 degrees North to less that 44 degrees North
90 degrees West to less that 97 degrees West