The Natural Area Code (or Universal Address) is a proprietary geocode system for identifying an area anywhere on the

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

, or a volume of space anywhere around the Earth. The use of thirty alphanumeric characters instead of only ten digits makes a NAC shorter than its numerical

latitude In geography, latitude is a coordinate that specifies the north– south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from –90° at the south pole to 90° at the north pol ...

longitude Longitude (, ) is a geographic coordinate that specifies the east– west position of a point on the surface of the Earth, or another celestial body. It is an angular measurement, usually expressed in degrees and denoted by the Greek lette ...

equivalent.

Two-dimensional system

Instead of numerical longitudes and latitudes, a grid with 30 rows and 30 columns - each cell denoted by the numbers 0-9 and the twenty consonants of the

Latin alphabet The Latin alphabet or Roman alphabet is the collection of letters originally used by the ancient Romans to write the Latin language. Largely unaltered with the exception of extensions (such as diacritics), it used to write English and th ...

- is laid over the flattened globe. A NAC cell (or block) can be subdivided repeatedly into smaller NAC grids to yield an arbitrarily small area, subject to the ±1 m limitations of the

World Geodetic System The World Geodetic System (WGS) is a standard used in cartography, geodesy, and satellite navigation including GPS. The current version, WGS 84, defines an Earth-centered, Earth-fixed coordinate system and a geodetic datum, and also descr ...

(WGS) data of 1984. A NAC represents an area on the earth—the longer the NAC, the smaller the area (and thereby, location) represented. A ten-character NAC can uniquely specify any

building A building, or edifice, is an enclosed structure with a roof and walls standing more or less permanently in one place, such as a house or factory (although there's also portable buildings). Buildings come in a variety of sizes, shapes, and fu ...

, house, or fixed object in the world. An eight-character NAC specifies an area no larger than 25 metres by 50 metres, while a ten-character NAC cell is no larger than 0.8 metres by 1.6 metres. Using a base 30 positional numeral system, NAC uses an alternate method which excludes vowels and avoids potential confusion between "0" (zero) and "O" (capital "o"), and "1" (one) and "I" (capital "i"): For example, the ten-character NAC for the centre of the city of

Brussels Brussels (french: Bruxelles or ; nl, Brussel ), officially the Brussels-Capital Region (All text and all but one graphic show the English name as Brussels-Capital Region.) (french: link=no, Région de Bruxelles-Capitale; nl, link=no, Bruss ...

is HBV6R RG77T.

Extension to three dimensions

The full NAC system provides a third coordinate: altitude. This coordinate is the arctangent of the altitude, relative to the Earth's radius, and scaled so that the zero point (000...) is at the centre of the Earth, the midpoint (H00...) is the local radius of the geoid, i.e. the Earth's surface, and the endpoint (ZZZ...) is at infinity. For example, the three-dimensional NAC for the centre of Brussels, at ground level, is HBV6R RG77T H0000.

References

External links

NAC Geographic ProductsUse the Global Postal Code System Now
{{Geocoding-systems Geocodes

Two-dimensional system

Extension to three dimensions

See also

References

Further reading

External links