Geographic Coordinates and the Universal Addresses

Shen, Xinhang, President, NAC Geographic Products Inc., 1608-45 Huntingdale Blvd., Toronto, ON, Canada M1W 2N8 Phone: (416) 496-6110, Email: admin@nacgeo.com

Abstract

The properties of traditional addresses and postal codes have been discussed. A new system - the Natural Area Coding System has been developed which has unified the concepts of points and areas by introducing a unified representation for both points and areas called Natural Area Codes (NACs). Eight- or ten-character NACs have been called Universal Addresses that will eliminate all the problems caused by different languages, written conventions and complicated components in addresses used in the world. Universal Addresses can be pinpointed on any maps, navigated with GPS receivers, and processed by GIS applications. They can also be used as Global Postal Codes to simplify automatic mail sorting and route optimization for all mail. Moreover, NACs as Universal Area Codes can significantly improve the efficiency in retrieving maps from large GIS databases; NAC grids can be used as an integrated universal map grid system that can be applied onto all kinds of maps with any scales.

Introduction

Traditional addresses are very complicated. It is not possible to prescribe a simple, mechanical rule for locating and interpret essential address components. Just in the United States, there are more than 50 variations in address formats [1] plus many non-standard abbreviations and local addressing conventions. In order to facilitate efficient mail processing, many countries have introduced postal codes such as US ZIP codes. A 9-digit ZIP can identify an area known as a “segment” such as a side of a street between intersections [2]. With 9-digit ZIP codes, domestic mail can be automatically sorted to the mailbags for single USPS employees with significant improvement in efficiency. However, most postal codes mapping national postal service hierarchies inherit many limitations, and useless in sorting international mail. Any changes in mail delivery hierarchies result in the changes of postal codes that create many troubles for both residents (remembering new codes, informing people of the changes, facing loss of mail) and post offices (settling complains, paying compensations, rerouting mail). Therefore, a global postal code system independent from any mail delivery hierarchies is demanded for fully automating mail sorting.

Locating physical addresses is what travellers, taxi drivers, and emergency services face everyday. Locating unfamiliar places with traditional addresses is not only a time consuming work but also very often results in complete failure no matter how emergent you feel. People can’t directly pinpoint these addresses on maps or figure out the distance and direction from them. Although GPS has been widely used in many areas such as highway snow removing [3], efficient farm operations [4], driver assessment [5], driving speed review [6], and even in golfing [7]. But the irrelevance between addresses and geographic coordinates and inconvenience in inputting addresses into GPS receivers make GPS useless to average consumers looking for addresses.

Handling and geocoding addresses have constituted the most time-consuming and expensive part in many GIS projects [8]. It is difficult to design a standard form for inputting all conventional addresses in GIS. Even when an input form for limited formats of addresses is created, inputting addresses into such a form is still very time consuming.

Therefore, highly efficient standard universal addresses for mail automation, locating and GIS applications are demanded. A substantial study of addresses and geographic coordinates has led to the birth of the Natural Area Coding System.

Definition

In the Natural Area Coding System, we use highly efficient unified codes to represent both points and areas with 30 most popular characters in the world (ten digits and 20 capital consonants). These codes are called Natural Area Codes (NACs) defined by a series of NAC grids. The first level NAC grid is formed by dividing the full range of longitude and latitude in the WGS-84 datum into thirty equal divisions respectively with one character representing each of these divisions as shown in Figure 1.

A cell on this grid is represented by two characters such as NAC: D H the black cell in Figure 1. To further divide each of these cells into thirty equal divisions, we get the second level NAC grid. A cell in the second level NAC grid is represented with four characters such as NAC: DK HP. Repeating the same procedure will make the third, fourth, fifth and even higher level NAC grids.

Figure 1 First level NAC Grid

If you have a pair of longitude/latitude coordinates, and want to know which NAC cells containing the point, you can use the following formulae to calculate:

where:

Once x₁, x₂, x₃, ..., x_n, y₁, y₂, y₃, ..., y_n have been calculated, you can use the following table:

Table 1 The Values of NAC Characters

Integer	Character	Integer	Character
0	0	15	H
1	1	16	J
2	2	17	K
3	3	18	L
4	4	19	M
5	5	20	N
6	6	21	P
7	7	22	Q
8	8	23	R
9	9	24	S
10	B	25	T
11	C	26	V
12	D	27	W
13	F	28	X
14	G	29	Z

 to find their corresponding characters: X₁，X₂，X₃，..., X_n，Y₁，Y₂，Y₃，..., Y_n，and then combine these characters to form a standard NAC：

NAC：X₁X₂X₃...X_n Y₁Y₂Y₃...Y_n

That is, starting with “NAC: ” followed by the string of characters for longitude, a blank space, and then the string of characters for latitude. Here n represents the level of NAC grid and can be any positive integer. Then you can say that the point is within this NAC. For example, a point at longitude west 79.39222 and latitude north 43.65145 is within NAC: 8 Q, also within NAC: 8C Q8, NAC: 8CH Q87, and NAC: 8CHK Q87P.

A series of neighbouring NAC cells can be represented by a single complex NAC. For example:

 0-Z as the end of a string in a NAC can be dropped for simplification, such as:

That is, any neighbouring NAC cells forming a rectangular area can be represented by a single complex NAC.

Applications

An important application is Universal Addresses defined by eight- or ten-character NACs that uniquely represents an address or a square meter area in the world. The major advantages of a Universal Address are:

With universal addresses, no matter from where and speaking what language, people can easily find their destinations with NAC enhanced maps or GPS receivers. If a city has marked all its street signs and house number plates with universal addresses, people can find their destinations efficiently in the city even without any helps, that will greatly benefit residents, tourists, taxi drivers, delivery companies, and especially emergency services.

Self-error checking capability. More than 80% of the area in the world is covered by water or deserts where no people live. If a universal address is written incorrectly, it will have more than 80% chance falling into these areas and will be easily found by mail sorting computers.

 The standard for including a universal address with a traditional address is to place the NAC on a new line after the end of the address no matter in which language. For example, our address can be written as:

Therefore, the universal addresses can be used immediately. If a post office has installed a NAC enhanced mail sorting program in their computers, they can take the advantages of the universal addresses, otherwise just use the old address without interference.

The Natural Area Coding System has many other applications too. The NAC grids can be used as a standard Universal Map Grid System that can be applied onto all kinds of maps with any scales and projections and lead to map independent universal grid coordinates.

NACs used as Universal Area Codes have filled the vacuum of standard codes for all areas in the world for retrieving maps and geographic data from large GIS databases. It just requires very few keys instead of typing many keys to specify the longitude, latitude, width and length of an area. If you want to retrieve a map of Ontario, from a world GIS, you need to type only two characters 8 Q.

Actually, NACs can be used to improve all location related applications.

Conclusion

The Natural Area Coding System is a very useful geographic technology. It makes human brains easy to remember and use high resolution geographic coordinates in their daily life. It has removed the obstacles in addresses caused by different languages and traditions and eased the exchanging of geographic information among different countries by providing efficient standard universal addresses, global postal codes, universal area codes and universal map grids.

References

About the Author

Xinhang Shen is the founder and CEO of NAC Geographic Products Inc. – a Toronto based Canadian company specialized in the development of GIS and mapping software and web GIS applications.