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The Universal Map Grid System

NAC or Address more applications

The NAC map grid system uses specifically selected constant longitude lines and constant latitude lines to form grid cells. There are a series of grid levels in the NAC grid system. The first level grid lines in the south-north direction are the lines on which their constant longitude equals to Longitude West 180, 168, 156, 144, 132, 120, 108, 96, 84, 72, 60, 48, 36, 24, 12, 0 degrees, and Longitude East 12, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168 degrees, respectively. The first level grid lines in the east-west direction are the lines on which their constant latitude equals to Latitude South 90, 84, 78, 72, 66, 60, 54, 48, 42, 36, 30, 24, 18, 12, 6, 0 degrees, Latitude North 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72, 78, 84 degrees, respectively. Each resulting cell is assigned one character from the Table of the NAC Character and Integer Correspondences both in the east-west direction and the south-north direction in the order as appeared in the table, that is, NAC: 0 0 is the NAC grid index of the first cell bounded by lines of constant longitude: Longitude West 180 degrees, Longitude West 168 degrees, and constant latitude: Latitude South 90 degrees and Latitude South 84 degrees. The first 0 in the NAC grid coordinates represents its longitude coordinate and the second 0 represents its latitude coordinate. The second level of the NAC grid is formed by dividing the cell of a first level grid uniformly into 30 subdivisions in both longitudinal and latitudinal directions, each of which is assigned one NAC character as the relative coordinate in both directions respectively, so is the third and other NAC grid levels. This definition of the NAC map grid system is equivalent to the algorithm in the definition of the Natural Area Coding System.

These grids can be applied to all maps such as a world map, country map, province map, city map and local community map, or maps for specific purposes. The resultant grid coordinates are of universal meaning, simplicity (an eight-character NAC specifically for a less than 25 by 50 meter area anywhere in the world) and multiple use. So, the NAC grid coordinates can become an important part of an address and everybody will like to keep them together with an address.

With this grid system, a map can be efficiently used to pinpoint any addresses with NACs and people do not need to look up the street from an street name alphabetic list and search for the street number along the street.

All information obtained from different maps can be easily correlated by the NAC grid coordinates and people will not have problems to link two maps of neighboring cities.

The NACs of two addresses anywhere in the world can be used to calculate their distance and their natural time difference and determine their relative locations.

Maps of the NAC cells can be named by their Natural Area Codes and stored systematically in a map library according to the NAC character order, which may give people much convenience to use the maps.

Tourist maps may include the list of hotels, restaurants, railway stations, airports, tourist information centers, parks, historic sites, shopping malls, and museums with their NACs, which will be very useful to tourists.

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