WO1996007170A1 - A geodetic coding system - Google Patents

Abstract

The present invention provides for a Natural Area Coding System based upon the natural coordinates of longitude and latitude. The system comprises a character string of n characters for the longitude and a second character string of n characters for the latitude of a particular location, each of the characters in each of the strings being selected from one of a number of possible characters. The natural area code can be obtained generally using the above algorithm where Longitude=180+Longitude East OR 180-Longitude West, or Longitude=Longitude East OR 360-Longitude West, or Longitude=180+Longitude West OR 180-Longitude East, or Longitude=Longitude West OR 360-Longitude East, and Latitude=90+Latitude North OR 90-Latitude South, or Latitude=90+Latitude South OR 90-Latitude North, F($(1,3)$) = Nearest whole number of ($(1,3)$) with x0=y0=0.5 OR Integer part of ($(1,3)$) with x0=y0=0, (a) sums the terms only when q>1, otherwise equals to zero. A is the number of characters in the character set. n and m are the number of characters in the longitude and latitude character string respectively. The resultant code will be X1X2X3...Xn Y1Y2...Ym, where X1,X2,...,Xn are the natural area code symbols corresponding to the integers x1,x2,...,xn, similarly for Y1,Y2,...,Ym. In the preferred embodiment of the invention, m and n are 4 and A is 30 using the ten digits, 0 to 9 and the capital consonants of the English letters as the character set, resulting in an 8-character code for each ara of the earth smaller than 50 meters in longitudinal direction and 25 meters in latitudinal direction for the whole world.

Description

A GEODETIC CODING SYSTEM

FIELD OF THF. INVENTION

The present invention relates to a new multi-use geodetic coding system called the Natural Area Coding System which generates an efficient global postal code system, a unified map grid system, an efficient emergency address dispatching system, an universal tele-communication address code system, a powerful navigation system, a memory-saving and user-friendly geographic and geodetic information management system and a universal geodetic reference system.

BACKGROUND OF THE INVENTION

Postal Services

Many countries presently utilize postal codes for simplifying mail sorting process to increase efficiencies, however, these codes have many disadvantages. Since each country has created its unique postal code system which differs from those of other countries, international mail can not be sorted and transported in the most efficient manner. Based on the distribution structure of postal corporations, postal codes may have to change frequently as postal corporations adapt to continually increased urbanization. These resulting changes inconvenience both the public and postal corporations. For example, the public has had to remember new postal codes, to inform their friends of changes, and some of their mail may have been lost or delayed. Postal corporations have had to cancel and assign codes, to inform all people within the area of changes, to convert old codes on mail to new codes, and to compensate for the loss of mail . Due to the frequent changes, postal corporations have had to update postal code

- l - databases, to revise and publish postal code books and postal zone atlases periodically. Many marketing companies have had to update their mailing lists, and risk losing their customers, letters and parcels due to postal code changes . The rapid increase in the amount of mail has also forced postal corporations to introduce longer postal codes to expand the capacity of postal code systems . These long meaningless and single-use codes have become more and more difficult for the public to remember and use.

Emergency Servings

Current emergency services use common addresses to find their locations. Since all the names of countries, provinces, cities, streets and street numbers are not developed systematically but historically, using common addresses to find their locations is in many cases inefficient. Therefore, emergency address dispatching centers in many developed countries have introduced powerful computers and large address-geocode databases for dispatching addresses, which has really increased the address dispatching efficiency. But this is still far from the maximum efficiency these systems should have. For example, these systems need to get the common address of an emergency call from the telephone company, input the address into a computer to search a street name in a street name alphabetic list and find out the coordinates of two street intersections between which the street number is located. The location of the address have to be interpolated from the coordinates of these two street intersections using the street number. Since the street numbers are not uniformly distributed, the interpolation may have a poor accuracy. If the street is new and not included in the database, the dispatching will fail. Since the database is so large, mistakes are inevitable, and sometimes the dispatched results may be completely wrong. If the correct location of an address has been obtained in the address dispatching center, it is still inconvenient to communicate it to the local emergency station. An emergency vehicle may need to be guided by the address dispatching center. Therefore, these systems are not really efficient and reliable in spite of lot of money being invested.

Map Grid Systems

Currently, map grid systems differ from map to map which give people many inconveniences in correlating the information obtained from different maps. Since most map grid systems are artificial, the grid coordinates of a map has always a use limited to the specific map and does not have any other uses, and nobody would like to include these coordinates as part of an address. Therefore, locating a street or an address on such a map may take a significant amount of time. Furthermore, since the grid systems are different, it may be difficult to link a street or highway between maps for two neighboring cities or maps of a city and its province. It is even more difficult to calculate distance and relative locations between two addresses located on two maps.

Geographic Information Systems

Computerized Geographic Information Systems (GIS) have greatly improved the efficiency of using maps and geographic databases, which have been widely used in managing natural resources, planning and construction, statistics, transportation, environmental protection, weather and earthquake analysis, agriculture, fishing, mining and exploring, tourism, education and research, etc. Since everybody lives in the world, the potential users may cover the whole population of the world.

However, these GIS' s have not been very efficient due to the lack of a language to describe geodetic points, areas on the earth and three-dimensional regions systematically and efficiently. The coordinates of a geodetic point in all current geodetic systems are always unnecessary long character strings. The description of an area on the earth or an underground three-dimensional region always needs a paragraph of words if it does not coincide with a political identity. Therefore, using current geodetic coordinates to store geodetic points, areas and regions in a GIS wastes huge amounts of memory. Storing geographic information related to specific areas or three-dimensional regions not only wastes memory but also may be poorly structured, which make the retrieval and use of the information inconvenient.

Navigation Systems

Navigation systems have been greatly improved since navigation satellites were launched. Now a hand-held Global Positioning System (GPS) unit can tell the coordinates of its location to an accuracy within 100 meters. These cheap and convenient units have greatly increased their uses outside military services. Mountain hikers, truck drivers, fishing boats, taxi and emergency vehicles are starting to use GPS units to navigate. If the price and volume of a GPS is continuously decreasing, more people may use it in daily life for finding locations and addresses like a watch to tell the time. However, there is still a great potential to increase the use of a GPS unit significantly. Since a GPS unit simply tells the geographic coordinates of a location, it is still difficult to be related to the common address. At present, a common address with its postal code does not include any information of its absolute geographic coordinates. If a postal code of an address represents its absolute geographic coordinates, the application of a GPS unit for daily life can be greatly increased. Therefore, equipped with a GPS unit, a person could easily find any address in the world. Telecommunication Address Codes

As computer science develops rapidly, telecommunication is undergoing a revolution. Telephone, fax, cellular phone, electronic mail, world wide web and file transfer protocol are entering more and more people's homes. It is an exciting time and people can notice changes everyday. At the same time, it is becoming increasingly burdensome to remember and use continually introduced address codes for new communication services and the codes of continually increased length for existing services. In fact, all these codes serve the same purpose: to represent an address. Why should so many single-use codes be introduced? Why should they not be unified to be one code for all the services? Furthermore, the unification of codes can also help the unification of the telecommunication network and optimize its capacity and efficiency.

Geodetic Reference Systems

There are so many geodetic reference systems in the world that no one can remember exactly how all these systems are defined and how the coordinates of these systems can be converted. For example, the longitude/latitude system has more than 20 different variations in different countries and different times. The longitude/latitude coordinates of a geodetic point can be written in many different ways both in order and in unit such as to put either latitude or longitude first, and to use writing forms: degree.decimals, degree:minute .decimals, degree :minute : second.decimals, etc. The differences of different systems and different writing conventions create serious problems for people to use, interpret and communicate geographic information. Huge amounts of time and money have been continuously wasted in all this unnecessary work. It has been a great demand to introduce an official universal geodetic reference system to eliminate all these problems. This effort has been made but not very successfully because no one specific system is superior to others and should be adopted as the universal geodetic reference system. Therefore, a geodetic system with more uses than all current systems and many advantages over all current systems will be an ideal candidate of the official universal geodetic reference system.

Summary of the Background of the Invention

As discussed above, the world requires a universal geodetic reference system which should have all the uses and properties of all current systems. The system should be able to be directly used for global postal services, emergency services, taxi and delivery services, and all telecommunication services. The system should unify all map grid systems, create efficient geodetic coordinates, represent areas and three-dimensional regions efficiently and link addresses with geocodes. The Natural Area Coding System is such a system which have all these uses and advantages.

SUMMARY QF THE INVENTION

The present invention in one aspect provides for a geodetic system based upon the natural coordinates of longitude and latitude. The system comprises a character string of n characters for the longitude and a second character string of m characters for the latitude of a particular location, each of the characters in each of the strings being selected from one of a number of possible characters. The natural area code can be obtained generally using the following algorithm: LONG = Aⁿ*Longitude/360, LAT = A^m*Latitude/180

Longitude=180+Longitude East OR 180-Longitude West or

Longitude=Longitude East OR 360-Longitude West or Longitude=180+Longitude West OR 180-Longitude East or Longitude=Longitude West OR 360-Longitude East and Latitude=90+Latitude North OR 90-Latitude South or Latitude=90+Latitude South OR 90-Latitude North

Nearest whole number of ( ) with

F( ) = OR

Integer part of ( ) with

q-1 X sums the terms only when q>l, otherwise equals to zero. i=l

A is the number of characters in the character set. n and m are the number of characters in the longitude and latitude character string respectively.

The resultant code will be XiX2X3-.. n Yl*2- - -^γπ where

XlfX2f --_'fXn ^are the natural area code symbols corresponding to the integers xi, X2, • • • *n, similarly for s.i, Y2, ... , m.

In an aspect of the invention, the geodetic coding system also includes a character string of n characters for the altitude where the character in the altitidue character string are obtained as follows: ALT = AP* Arctan ((Altitude + R)/R)/90

where F( ), zo, A and q have the same meaning as above and p is the number of characters in the altitude character string; R is the distance from the earth center in km along the gravitational force line to the geoid surface and can be approximated by the earth radius at the location:

f = (a - b) /a ; e = 2*f - f² ;

N = a/sqrt d - e² * sin² (Latitude) )

R = N*sqrt [l- e² * (2-e² ) * sin² (Latitude)

where a is the semi-major earth axis (ellipsoid equatorial radius) equal to 6378.1370 km; b is the semi-minor earth axis (ellipsoid polar radius) equal to 6356.7523 km; sqrt f) is the square root function; sin () and cos () are triangular functions; the symbol / is the division sign and the altitude string ZιZ2Z3...Z_p corresponds to the integers ^zl, Z2, Z3- • -^zp-

In yet another aspect of the invention there is provided a map of a region of the earth having grid lines corresponding to the Natural Area Code of the region as determined according to the above .

In the preferred embodiments of the invention A is an integer of between 26 and 36, more preferably 30 or 31, most preferably 30 and m, n and p are integers between 2 and 6, more preferably 3 or 4, most preferably 4. BRIEF DESCRIPTION OF THE DRAWINGS

The above as well as other advantages and features of the present invention will be described in greater detail according to a preferred embodiment of the present invention in which:

Figure 1 is a world map showing the major grid lines according to a preferred embodiment, and;

Figure 2 is a map of a section of Toronto, Ontario, Canada, illustrating the natural area code according to the preferred embodiment .

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

The present invention provides for a geodetic coding system called The Natural Area Coding System which is based upon the natural coordinates of longitude, latitude and altitude. The Natural Area Coding System is particularly useful as a global postal code and map coordinate system. The use of the Natural Area Coding System permits the optimization of location of and delivery to an exact address .

The Natural Area Coding (NAC) System generates a unified global postal code system, an efficient and cost effective address dispatching system for all kinds of emergency services, a unified map grid system for all kinds of maps of all scales, an efficient and memory saving geographic and geodetic information management system, an efficient Navigation system, a unified telecommucation and a universal geodetic reference address code system for all sciences and engineerings related to the earth, space and universe. It unifies all these systems into one single system which can greatly simplify the descriptions of locations, areas on the earth, three-dimensional regions in the earth, atmosphere and space, and accelerate the communication between all these fields. The two- dimensional Natural Area Code (NAC) System in a preferred embodiment generates a unique eight character (digit or letter) Natural Area Code (NAC) for each area less than 25 by 50 meters all over the world based on the longitude and latitude of the earth. It is also a standard grid system for all kinds of maps and geographic information systems . A NAC can be used as a global postal code to make the postal services, especially the international postal services work more consistently, harmonically and efficiently. It can greatly speed the process of dispatching addresses for ambulance, firefighters, police, taxi drivers, express delivery services, transport companies, individual people, etc., to significantly save time, cost, property and even lives. The NAC System has all the functions of existing geographic grid and coordinate systems and creates more additional functions. The three-dimensional NAC System is the extension of the two-dimensional NAC System, which uses very few characters to represent a three-dimensional region with arbitrary size and ratio of Longitude Span: Latitude Span: Altitude Span. The three-dimensional NAC System can be utilized in grid and coordinate systems related to the earth used in Geology, Geography, Oceanography, Mining and Exploration, Environmental Science, Ecology, Space Science, Astronomy, etc. to make the description simpler and the information exchange easier.

The two-dimensional Natural Area Coding System for use as a postal code and map coordinate system consists of two strings of a number of symbols to indicate the longitude and latitude. The Natural Area Coding System may use any number of symbols but the number of symbols used should be such that the system is usable to indicate a sufficiently small area for use as a postal code and map coordinate system. The Natural Area Coding System should also be flexible enough in length, i.e., it can consist of any two strings of symbols without strict limit in length so as to avoid strings which would be an affront to public morality or social customs. When used as a postal code system, a locally defined third string may be added to increase the efficiency of mail delivery.

In a preferred embodiment, the Natural Area Coding System is a geodetic coding system originating from the earth center and extending to the infinitely distant universe. In its preferred embodiment, it employs a character set consisting of digits 0 to 9 and all English capital consonants since these characters are the most popular characters widely used in common languages such as English, French, Spanish, German, Chinese, and all categories of science and engineering. Each character in the character set represents an integer ranging from 0 to 29, as shown in the following table:

A Natural Area Code (NAC) consists of three character strings separated by blank spaces. The first character string represents longitude, the second string represents latitude, and the third string represents either altitude or a locally defined string depending upon the application. The system divides the whole range of longitude (0 - 360°), latitude (0 - 180°) and altitude (from the earth center to the infinite outer space) into 30 discrete divisions respectively, each of which is named by one character from the character set according to the order of the characters . And each resulting division is divided into 30 subdivisions, and each of the subdivisions is named by one character. The division process can continue to the third, fourth, and other levels. The resulting regions are called NAC blocks. Therefore, a first level NAC block is named by a NAC of three characters separated by blank spaces, each of which represents the character string for longitude, latitude and altitude respectively, for example, NAC: 5 6 7. A second level NAC block is named by a NAC of six characters to form three character strings: the first two characters form the longitudinal string, the third and fourth characters form the latitudinal string, and the last two characters form the altitudinal string. A blank space is placed between theses strings, for example, NAC: JB KH LN represents a second level NAC block, in which the characters J, K and L represent coordinates of a first level NAC block which contains the second level NAC block, and the characters B, H and N are the relative coordinates of the second level NAC block in the first level NAC block. A NAC block at another level is named similarly. If the third string of a NAC is omitted, the resulting NAC represents an area on the earth surface. It is worthwhile pointing out that a NAC represents an area or a three- dimensional region (simply called "region" in the following) , while current geodetic coordinates represent only geodetic points. A geodetic point in the Natural Area Coding System can be expressed by a relatively small area or region since an absolute point is the limit of an infinitely small area or region. That is, a NAC has both functions: representing an area or a region and representing a geodetic point. This is a very important property of a NAC, from which many applications of the Natural Area Coding System originate. The NAC of a region that contains a geodetic point expressed by the longitude, latitude and altitude coordinates in the WGS-84 system[1] can in the preferred embodiment be determined by the following algorithm:

LONG = (Longitude + 180) /360 xi = Integer part of ( LONG* 30) x₂ = Integer part of ( ( LONG*30-x ) *30) x₃ = Integer part of ( ( ( LONG*30-X_!) *30-x₂) *30) x₄ = Integer part of ( ( ( (LONG*30-xι) *30-x₂) *30-x₃) *30)

LAT = (Latitude + SO) /ISO yi = Integer part of ( LAT*30 ) y₂ = Integer part of ( ( LAT*30-y₁) *30) y₃ = Integer part of ( ( ( LAT*30-y₁) *30-y₂) *30) y₄ = Integer part of ( ( ( (LAT*30-y₁) *30-y₂) *30-y₃) *30)

ALT = Arctan ( (Altitude + R) /R ) /90 z₂ = Integer part of ( ALT*30) z₂ = Integer part of ( ( ALT*30-z₁) *30) z₃ - Integer part of ( ( ( AL1*30-z₁) *30-z₂) *30) z₄ - Integer part of ( ( ( (ALT*30-z₁) *30-z₂) *30-z₃) *30)

where Longitude is positive in the eastern hemisphere and negative in the western; Latitude is positive in the northern hemisphere and negative in the southern; both Longitude and Latitude are in degrees plus decimals; Altitude is measured along the gravitational force line from the geoid surface of the earth in kilometers; Altitude is positive above the geoid surface and negative below the surface; the symbol * is the multiplication sign; x_lf x_2f x₃, x₄, ..., y_lf y_2r y₃, y₄, ..., z_lf z₂, z₃, z₄, ... are integers ranging from 0 to 29 here; Arctan ( ) is the arctangent function with value in degrees; R is the distance from the earth center in km along the gravitational force line to the geoid surface and can be approximated by the earth radius at the location:

f = (a - b)/a ; e = 2*f - f² ;

N = a/sqrtd - e² * sin² (Latitude) )

R - N*sqrt[l- e² * (2-e² )* sin² (Latitude) ] where a is the semi-major earth axis (ellipsoid equatorial radius) equal to 6378.1370 km; b is the semi-minor earth axis (ellipsoid polar radius) equal to 6356.7523 km; sqrt f) is the square root function; sin () and cos () are triangular functions; the symbol / is the division sign.

Once x_{l r} x₂, x_3f x₄, . . . , y_{l f} y₂, y₃, y₄, . . . , z_{l f} z₂, z₃, z₄, . . . are calculated, the corresponding characters can be found from the Table of the NλC character and integer correspondences: X_{l t} X₂, X₃, X₄, . . . , Y_\ , Y₂, Y₃,

Y₄, . . . , ∑i, Z₂, Z₃, Z₄, .... Then, the Natural Area Code of the region is written as NAC: X₁X₂X₃X₄ . . . Y_X Y₂Y₃ Y₄ . . . ZjZ₂Z₃Z₄ . . . with a blank space between any two character strings. The first character string of a NAC represents longitude, the second string represents latitude, and the third represents altitude. If a NAC has only two character strings, then the NAC represents an area on the earth surface and the two character strings represent the longitude and latitude respectively, as defined in the beginning of this section. For example, NAC: 8KD8 PGGK represents a 25 by 50 meter area in the White House, while NAC: 8KD8 PGGK H000 represents a region 25 meters wide, 50 meters long and 25 meters high measured from the geoid surface under the White House. The number of characters to be used in a character string of a NAC representing the geodetic point is determined by the required resolution or the resolution of the original coordinates of the longitude, latitude and altitude. A NAC using more characters represents a smaller area or region. The smallest area or region containing the geodetic point is the one of the size equal to the error range of the coordinates. Therefore, when a NAC is used to represent a geodetic point, it has both the information of the location and its error range.

A group of neighboring NAC blocks can be represented by a simplified notation. For example, two earth surface areas of NAC: HJ KL and NAC: HK KL can be represented by NAC: HJ-K KL. Four areas of NAC: HJ KL, NAC: HK KL, NAC: HJ KM, NAC: HK KM can be expressed by NAC: HJ-K KL-M. A group NAC such as NAC: HJ KO-Z can be simplified as NAC: HJ K since 0-Z covers all NAC cells in its higher level division. Therefore, NACs of areas or regions may have different characters and the symbol "-" in their character string such as NAC: 1 2 3, NAC: IK 2 3, NAC: 1J-L 2H 3K, NAC: HJKL-Q GTFFD-H BGHV-Z, NAC: D H, NAC: DFHJ HG-GH, NAC: DF-H HG-K, NAC: 1234 KHJL. These simplified notations make the Natural Area Coding System very efficient in representing an area or a region of any size and any longitudinal span, latitudinal span and altitudinal span anywhere on the earth surface or anywhere in the universe. Therefore, using a NAC to represent a geodetic point, an area on the earth or a region is the most efficient way compared with using all other systems and can save more than 50% of characters or computer memory in representing geodetic information.

If the NAC of a region is known, then the longitude, latitude and altitude of the southwestern lower corner of the region can be calculated by the following procedure:

First, convert all characters Xi, X₂, X₃, X₄, ... Yi, Y₂, Y₃, Y₄, ... Z_lf Z₂, Z₃, Z₄, ... into integers x_lf x₂, x₃, x₄, • • • Yir y₂, Y3r ii • • • ^zι , ^z2r z₃, z₄, ... according to the Table of the NAC character and integer correspondences .

Then use the following formulae to calculate coordinates:

Longitude = (x₁/30+x₂/30²+x₃/30³- χ₄/30⁴+ . . . ) *360-l80 Latitude = (y₁/30+y₂/30² +y₃/30³ +y₄/30 + ... *180-90 f = (a - b) /a ; e = 2*f - f² ; N = a/sqrt (1 - e²*sin² (Latitude) )

R = N*sqrt [l - e² * (2-e² ) *sin² (Latitude) ]

Altitude = R*tan ( (z₁/30+z₂/30²+z₃/30³-rz₄/30⁴-r . . . ) *90) -R

The northeastern upper corner of the region can be calculated by repeating the same procedure with the same integers except adding 1 to the integer corresponding to the last character of the longitude and latitude strings of the NAC. The coordinates of the center of the region are the averages of the corresponding coordinates of these two corners. Then, the region can be completely determined by the coordinates of these three geodetic points.

If the NACs of any two areas on the earth surface have been given as: NAC_: and NAC₂, then the earth surface distance between the centers of these two areas can be calculated as follows:

1. First, calculate the longitude, latitude and the local earth radius of NAC_! and NAC₂: a_{l f} b_{l r} j and a₂, b₂,

R₂ respectively using the above formulae;

2. Then calculate the distance S between them approximately as follows:

S = R_av*Arccos (cosb₁ *cosa₁ *cosb₂ *cosa₂

+cosbι *sina_x *cosb₂ *sina₂+sinb *sinb₂)

where R_av = (Rj + R₂) /2.

The natural time difference between these two areas can be calculated by the following equation:

AT = (a -a₂) *24/360 where the positive value means area 1 has the day starting ΔT hours earlier than area 2.

THE NAC GLOBAL POSTAL CODE SYSTEM

The NAC global postal code system has been developed as the first application of the Natural Area Coding System. A standard NAC global postal code is an eight-character two-dimensional Natural Area Code representing an area about 25 by 50 meters anywhere on the earth surface. The global postal code for an individual house or an apartment is defined by the following:

(a) If an eight-character NAC represents an area with only one house and without any postal zone borders, then the global postal code of the house is the same as the NAC, for example, NAC: 7HGG KJ9L.

(b) If the NAC represents an area with several houses, the global postal code of each house in the area is the NAC plus a locally defined third character string which people may define themselves using a family name, a location name or a name of their choice. It is preferred that the locally defined third string employ characters from digits or English capital letters, have at least one vowel other than "I" or "0", not include blank spaces, and be unique in the area, for example, NAC: 7HGG KJ9L DAVID. The requirement of at least one vowel other than "I" and "0" is to distinguish the third string from the altitude NAC string which does not include any vowels: "A", ^WE", "I", "0", "U", "Y" . The characters "I" and "0" are so similar in appearance to "1" and "0"; that they may not be clear enough to distinguish the locally defined string from the altitude string.

(c) If the NAC represents a high-rise building with many apartments, the global postal code for each apartment is the NAC plus a locally defined string such as an apartment number named in a way similar to case (b) , for example, NAC: HGJK PLLT A509.

(d) If a NAC represents an area split by a postal zone border, and a house is located in the larger part of the area, then the global postal code of the house is the NAC or the NAC plus a locally defined string; if a house is completely within the smaller part of the area, then its global postal code may be a nine- or ten-character NAC to specify the location of the house more accurately, instead of an eight-character NAC; if a house in the smaller part of the area occupies part of another NAC area called B which belongs to the same postal zone as the house and is not split by any postal zone borders, then the global postal code of the house is the NAC of area B or the NAC of area B plus a locally defined third string.

(e) The longitudinal distance of the area represented by an eight-character NAC becomes small when it is close to the poles. For this situation, a seven- or six-character NAC may be used as the global postal code of the area.

(f) If a house itself is split by a postal zone border, the global postal code of the house may be a nine- or ten-character NAC representing the location of its main entrance.

Having obtained the global postal code, it may be included in an address on a letter as extra information immediately no matter how many post offices have already started sorting mail based on the codes. If some post offices have been sorting mail based on the codes, a letter with a NAC global postal code can be sent faster.

The written convention of the global postal code on a letter is to write the global postal code on an extra line at the bottom of the current address and domestic postal codes no matter what kind of language and address order are used. For example:

Mr. Xinhang Shen

50 Stephanie Street, APT 509

Toronto, ON M5T 1B3

Canada

NAC: 8CHD Q87M A509

This writing convention allows post offices to sort mail by either domestic postal codes or NAC global postal codes. Therefore, the domestic postal code systems can be replaced by the NAC global postal code system gradually.

Post offices can use character recognition techniques to read addresses. If the last line of an address starts from "NAC", then the following character strings will be processed as a NAC global postal code. One of the algorithms for computers to sort mail based on the NAC global postal code is explained in the following:

If postal services do not want to change anything except the mail sorting software, then the software can be programmed according to the following procedure:

1. Convert the first two character strings of the NAC global postal code into decimal longitude and latitude;

2. Use the city boundary file (boundary files are described in greater detail below) to check whether the destination is within the city or not;

3. If the destination is within the city, then use the boundary files of the inner city areas to find out the area of the destination and to transport the mail to the post office in charge of the area; 4. If it is not within the city, then use the boundary file of the country to check whether the destination is in the country;

5. If the destination is in the country, use the boundary files of postal zones at the city level to find out the postal zone containing the destination and to transport the mail to the postal terminal in charge of the postal zone;

6. If it is outside the country, then use the boundary files of countries to find out the mail destination country and to transport the mail to the country's postal terminal;

To check whether the destination is within an area, the mail sorting program may first calculate the distance R between the destination and the reference point of the area, then compare R with the maximum distance R_max from any point in the area to the reference point. If R > R_max, then the destination is outside the area. If R < R_max, then the program can compare R with the minimum distance R„_in from any boundary node to the reference point. If R < R_mi_n, then the destination is within the area. If R > R_mi_n, the program has to calculate the angle α of the vector from the reference point to the destination. Assume that each boundary node is represented by the angle and length of the vector from the reference point to the boundary node. Assume that there is only one boundary node corresponding to one angle in the area, while a complicated area may be divided into several such simple areas. Therefore, the program can find out two boundary nodes: the vector from the reference point to one of the nodes has a length R₂ and angle α₂ equal to the maximum angle smaller than O ; the vector from the reference point to the other node has a length R₂ and an angle α₂ equal to the minimum angle larger than α . Then the program can determine that the destination is within the area if Ri *R *sin ( - 0L^~ι ) + R *R₂ *si n (a₂ - a) < R₁ *R₂ *s i n (a₂ - a₂ ) , otherwise it is outside the area.

The mail sorting software based on this algorithm can work together with the existing structure of post offices and help sort all mail from the international level to the final address automatically. Moreover, since the current distribution structure of postal corporations may not be optimal, this mail sorting program also allows the post offices to adjust their mail transportation routes to send mail more efficiently. For example, Canada Post Corporation may set up more international postal terminals, then other countries can send mail to a specific Canadian postal terminal if the distance from the mail destination to the terminal is the shortest. This adjustment can prevent some situations such as a letter from Seattle to Vancouver being sent through New York City and Toronto and then to Vancouver - an unnecessary long trip which wastes both time and money.

In addition, the NAC global postal code system has many other advantages over current postal code systems:

* The NAC global postal code is assigned to every mailing address in the world, with much higher resolution than any other postal codes. With a NAC global postal code, a letter can be sorted from the world level to the final address automatically.

* The code is permanently attached to the area and never changes. This quality can prevent unnecessary inconvenience to both the user and the post office wasting of time and money and resulting loss of mail.

* The NAC global postal code need not be assigned by a post office, which can help people living in newly developed areas to get their postal services immediately. * The code can be used instead of the domestic postal code to save costs in revising and publishing postal code books and postal zone atlases periodically.

* The code can be used for all other services related to addresses such as emergency services, taxi and delivery services, and in the future, telephone, fax and internet services.

* The code can be obtained from maps with the NAC grid or by Global Positioning System (GPS) units with the NAC display. It can also be derived from the longitude and latitude coordinates obtained from ordinary maps or measured by other methods.

* The codes can be used to determine the distance and natural time difference between any two addresses and their relative locations in the world.

* The code can be directly used in navigation to find addresses or locations by ambulances, trucks, airplanes and individuals equipped with GPS units.

* The code can help people to pinpoint an address on a map of the NAC grid conveniently in spite of the amount of detail and the scale of the map, which can help people to determine the environment and climate of an address.

* The code can be easily remembered because of its clear meaning, reasonable length, multiple uses and multiple access.

* The system is self-motivated. Since the system can start to work immediately parallel to the current domestic postal code systems, it does not need any international agreements to initiate the system. Any country can start to use the system directly when it is ready itself and will receive all the benefits of the system immediately.

* The code has certain self-error-detecting function. There is a greater than 80% chance for a computerized mail sorting program to quickly identify a wrong NAC global postal code since a random NAC may represent an area in oceans where no one lives . This property can avoid most mail with the wrong code being sent to the wrong place.

* NAC global postal codes can also help people to understand, interpret and communicate all geographic, geologic, ecological, meteorological, oceanographic, archeological, environmental and astronomic information represented by Natural Area Codes.

A possible disadvantage is that a NAC global postal code can only be sorted efficiently by computers but not by human beings due to the handling of postal zone boundary files. However, the continuous decrease of computer prices have made computers cheaper and cheaper, and most post offices in developed countries already have the ability to buy computerized mail sorting equipment .

THE NAC EMERGENCY ADDRESS DISPATCHING SYSTEM

A new efficient, reliable and low-cost emergency address dispatching and locating system has been developed based on the Natural Area Coding System. The principle of the system can be applied to both the map-based address dispatching system and the computerized address dispatching system. Both systems uses the Natural Area Codes of addresses to dispatch addresses and let the emergency caller or the telephone company directly supply the NAC of an address at which emergency services are required, since the NAC is so useful that everybody will know it and telephone company's address databases will include it. With the NAC, the address dispatching staff can find the address by using a map with the NAC grid directly. Then they can inform the emergency station closest to the address and tell them the address and its NAC. Or, the address and its NAC may be transmitted electronically by the telephone company to the emergency address dispatching computer directly and the computer will forward electronically all the information automatically to the emergency station closest to the address using the information supplied by the NAC. Equipped with a map of the NAC grid or a computerized map of the NAC grid with a route optimization function, the driver of the emergency vehicle can use the NAC to find out the exact address on the map and figure out the best route to reach the location immediately. Since the driver knows the address exactly, he/she does not need to check street names and numbers frequently and does not need any dispatching center's guidance. If the driver is equipped with a GPS unit with the NAC display, the process will be even more reliable and efficient, especially for an air ambulance. This process may save significant time in the emergency services and help reduce the loss of life and property due to fire, disease and crime. The system can overcome all the problems of current map-based and computerized address dispatching systems. Moreover, this system will also save all the money invested in the large address database set-up and maintenance. Therefore, it is a more reliable, efficient and cost-effective address dispatching and locating system. This system still works efficiently without computers since the NAC of an address can be very conveniently found on maps of the NAC grid. Equipped with maps of the NAC grid, the address dispatching center and emergency vehicle driver can dispatch and locating addresses based on the NAC of an address told by the emergency caller. This property can help developing countries to set up an efficient and low cost emergency address dispatching system. THE NAC MAP GRID SYSTEM

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°, and Longitude East 12°, 24°, 36°, 48°, 60°, 72°, 84°, 96°, 108°, 120°, 132°, 144°, 156°, 168°, respectively. The first level grid lines in the east-west direction are the line 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°, Latitude North 6°, 12°, 18°, 24°, 30°, 36°, 42°, 48°, 54°, 60°, 66°, 72°, 78°, 84°, 90°, respectively. Each resulting cell is assigned one character from the Table of the NλC 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 coordinates of the first cell bounded by lines of constant longitude: Longitude West 180°, Longitude West 168°, and constant latitude: Latitude South 90° and

Latitude South 84°. 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 cell 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. Examples of two such maps, namely a world map showing the major grid lines and a map of a section of Toronto, Ontario, Canada illustrating a grid at the third level are shown in Figures 1 and 2 respectively. 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 it is not necessary 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 it will be easy 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 make it more convenient 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 then be very easy to locate. THE NAC GEOGRAPHIC AND GEODETIC INFORMATION MANAGEMENT SYSTEM

Since the Natural Area Coding System has created a simple, systematic and unique universal code called NAC for every area of any size anywhere on the earth and every three-dimensional region of any size anywhere in the universe, all the data associated with areas or regions can be very well organized, stored and retrieved. The NAC geographic information management system stores geographic data according to the NAC character order as shown in the Table of the NλC character and integer correspondences .

A NAC geographic information database for the whole earth surface may contain two main directories. The first main directory is a data directory which contains a feature directory containing files of continents, countries, oceans, deserts, forests, transportation networks, and other global features. This main directory also contains the first level subdirectories named by the NACs of the first level NAC cells. A first level subdirectory contains a feature directory containing files of country boundaries, rivers, lakes, and other features of the cell, and also contains the second level subdirectories named by the NACs of the second level NAC cells. This structure can continue to provide as much detail as required. The name of a subdirectory named by a NAC consists of the longitude string and latitude string of the NAC linked by the sign "_" . The geographic coordinates are represented by the NACs with length suitable to the required resolution.

The second main directory is the index directory which contains an index file listing the names of global identities alphabetically such as countries, continents, oceans, forests and deserts with their sequence codes, and also contains the first level subdirectories named by the sequence codes. A first level subdirectory for a country contains an index file with the first line listing the NACs of the areas covering the country and the following lines listing its province or state names alphabetically with their sequence codes, and it also contains the second level subdirectories named by the province or state sequence codes. A second level subdirectory is constructed similarly, as is a third level subdirectory. The structure can continue to provide as much detail as required.

A first level subdirectory for an ocean, a desert, a forest, or other global natural identity can be constructed in a way similar to the first level subdirectory for a country provided the names of provinces or states are replaced by regional natural identities of the global natural identity.

The NAC geographic information system user interface may have a graphics window for displaying a map and a column of tool icons for a user to use a mouse or other positioning device to add or remove some features to the map and select locations of interest to zoom in or out. The screen may also have text input boxes for a user to input the name of a country or the NAC of an interesting area. If a country name is input, the software will go to the index directory to find out the sequence code of the country from the index file, and then go to the subdirectory named by the sequence code to get the NACs of the country from its index file. Using the NACs of the country, the software can go to the data directory to find out the subdirectories named by the NACs and display the country boundary on the screen. The user can also add or remove other features to or from the country map. From this point, the user can also retrieve a map by inputting a province or state name or a NAC. If a user inputs a NAC in a text box, then the software will directly go to the data directory to retrieve the map represented by the NAC. This is very convenient for a user to go to a map of interest because they need input only a very short NAC which contains the information of both where and what size the area is. This function is much more efficient than a mouse driven zooming function and the text input of a political identity.

A NAC geodetic information management system for a three-dimensional database can be constructed in a way similar to a NAC geographic information management system for the earth surface, using the NACs of three-dimensional NAC geodetic blocks instead of two-dimensional NAC geographic cells as the directory names. The three- dimensional system will be very useful to geologists, oceanographists, meteorologists, miners, earth and space scientists.

The NAC geographic and geodetic information management system has the following advantages over all current GIS's:

* It requires much less memory to save geographic or geodetic coordinates. In the NAC geographic and geodetic information management system, all geographic or geodetic coordinates are saved in NACs which needs much fewer characters than other geographic or geodetic coordinates such as (longitude, latitude, height) and UTM coordinates. For example, an eight-character NAC represents a geodetic point with the resolution to 1.6 seconds in longitude and 0.8 seconds in latitude which requires at least 15 characters represented by longitude and latitude coordinates.

* It cuts significant memory by avoiding map overlaps. Current GIS's usually save digital maps according to the political identities. There may be two strategies to save these maps: one is to save political identities without any neighboring areas and the other is to save political identities with certain neighboring areas. Although the first one can avoid all map overlaps, it is extremely difficult to link geographic information of neighboring political identities. The second one is more common than the first one, which can give all the information of the neighboring areas of a political identity, but includes many map overlaps which may require more than 50% extra memory. This problem has been solved in the NAC geographic information management system since it saves only the maps of the NAC cells and all political identities are represented by a series of NAC cells. The NAC cells are not specific for political identities, so they include all the neighboring areas of a political identity. In addition, they are never overlapped on each other but shared by all political identities with a part on them. Therefore, the NAC geographic information management system can link geographic information between political identities easily by displaying the neighboring areas of a political identity but does not need the map overlaps.

* It includes the option to retrieve interesting maps directly no matter where and what sizes the areas are by simply inputting the NACs of the areas, since the NAC of an area has included the information of both the universal location and the size of the area. This function can greatly improve the efficiency of the system, and users do not need click mouse many times to wait for the system to go to the interesting locations with appropriate scales step by step.

* The system can also help users to store their own geographic data into the database efficiently if it includes a function for users to view and edit the database since the database structure is so systematic that any geographic data can be saved as a feature file under the directory named by the NAC of the area. Therefore, a NAC geographic information management system is a progressive system which can be updated by users all the time.

With so many significant advantages, the NAC geographic and geodetic information management system is an economic, efficient and user friendly geographic and geodetic information system.

THE NAC NAVIGATION SYSTEM

The NAC navigation system comprises a Global Positioning System (GPS) unit with a NAC display and NAC input keyboard and/or a map with the NAC grid or a NAC geographic information management system.

Currently, the GPS unit can directly show the WGS-84 geodetic coordinates (longitude, latitude, height) by analyzing the signal from a series of satellites. It originates from military use but has started its civil services now. Many airplanes, ships and trucks have already been equipped with GPS units which can help them locate their current locations and destinations, and measure their moving speeds. Some explorers, hikers and hunters are using GPS units too. The price of a GPS unit has dropped from thousands of dollars to hundreds of dollars and its weight and volume have decreased significantly too. A hand-held GPS unit may weigh less than a kilo, is as small as a wallet and costs only several hundred dollars, but can tell the universal coordinates of a location with an error less than 100 meters. The trend of the GPS unit development has shown that in the near future, it will be even cheaper and smaller and may become a necessary tool of everybody to tell the location like a watch to tell the time.

However, there is a problem for GPS users since the geodetic coordinates are very difficult to be directly related to a geographic location represented by its common name and a destination expressed by its common address. For example, if an individual takes a taxi equipped with a GPS unit to go to an unfamiliar address, the GPS unit will not help the driver if he/she is not given the geographic coordinates. But the geographic coordinates expressed by long character strings of longitude and latitude are really difficult for people to remember and use.

But the Natural Area Code of an address can help. It is short and logical which has all the functions of any other global geodetic coordinates and can be easily obtained, remembered and used, and can become a necessary part of an address. To use a GPS unit to navigate to a destination expressed by its NAC, the GPS unit may directly show the distance from the current location to the destination and its relative orientation.

The destination can also be easily located and marked on a map with the NAC grid, and the starting point, the path of the trip and the destination point on a map of the NAC grid or a digital map with the NAC grid in a computer may be located and marked before the trip. The user can also draw the actual path on the map during the trip and make the analysis after the trip.

THE NAC UNIVERSAL TELECOMMUNICATION ADDRESS CODE SYSTEM

It is becoming more and more difficult to manage continually increased numbers, codes and addresses which are always meaningless and designed for specific purposes, such as: postal codes, telephone numbers, fax numbers, telex numbers, electronic mail addresses, world wide web page addresses, and many other addresses. In addition, these numbers are also changing frequently and becoming longer and longer. Why should so many codes be used which really serve the same purpose: to represent an address? As pointed above, postal code systems can be unified by the Natural Area Coding System. In addition, many other address code systems can also be unified by the Natural Area Coding System.

The Natural Area Coding System may be utilized to create all codes, numbers and addresses related to a location for telecommunication.

A NAC telecommunication address code can be constructed in the same way as the NAC global postal code and in most situations the NAC telecommunication code is exactly the same as its NAC global postal code if there is only one telecommunication unit in the address or the telecommunication unit has been integrated by a computer which can automatically connect different signals to their corresponding equipment such as a telephone, fax, television set or the computer file receiver.

If in one house or one office there are more than one separate telecommunication units, people can assign a unique locally defined third string to every unit to generate its telecommunication address code.

Generally, a NAC telecommunication code is an eight- character NAC plus a locally defined third string. But for a cellular phone or other large range valid tele¬ communication services, the address code may comprises only one unique user defined string, or a two-, .four- or six- character NAC plus a unique user defined third string within the corresponding area.

The rules for defining a user-defined character string for telecommunication address code are the same as those for defining the third string in a NAC global postal code. A cellular phone address code comprising only a user defined string is a global valid address code which can be recognized and used anywhere in the world. A cellular phone address code comprising a NAC plus a user defined string will be valid within the area defined by the NAC. A shorter NAC plus a user defined third string will be valid in a larger area. Large international companies may use globally valid cellular phone codes, while small local companies may utilize cellular phone codes valid within small areas.

The telecommunication address code system can be used efficiently on a new telephone set on which it has keys of all digits and English letters together with several function keys: a space key, a hyphen "-" key, an Enter key and some other function keys.

If you want to call a person, it is only necessary to input the three character strings of the NAC phone code separated by space keys and then press Enter.

If there is no third string in a NAC telephone code, the two strings separated by a space key are inputted and then Enter is pressed.

The NAC telephone set is preferably provided with a display window to display the codes and an erasing key for correcting wrong characters during the input. It may also be provided with a function key for the user to display the distance between the caller and the receiver and to show the price of the call before the user presses Enter. Therefore, the caller can make a decision whether to make the call or not before pressing Enter.

The keys and their bit codes of a NAC telephone set should be the same as those of a computer keyboard, which may help produce an integrated computer system for phones, faxes, and internet services in the near future. Using a current touch tone telephone set to call a NAC telephone code, a person may use two keys "*" and "#" as the prefix of each NAC character string and two digits to represent a NAC integer corresponding to a NAC character and press "*" and "*" to enter the code. NAC integer 0-9 would be replaced by 00-09 respectively. The English capital vowels could be defined as: A = 30, E = 31, I = 32, 0 = 33, U = 34, Y = 35, "-" = 36. For example, if you want to call me at NAC: 8CHD Q87M SHEN, you can press these keys: "*", "#", "0", "8", "1", "1", "1", "5", "1", "2", w -if ft /f AL rt w /' wy tt w * /' // # //

"2", "4", "1", ^w5", "3", "1", "2", "0", "*", and "*".

If a telephone code has only a user defined string, then you just press "*", "#", the corresponding digits and then "*", "*" on a current touch phone.

Alternatively, as most telephone sets numerical keys are also provided with alphabetic indicators, these alphabetic indicators can be utilized to input the alphabetic characters of the NAC. If the character in the NAC string is a number, then the number key alone is pressed. If the character in the string is a letter, then the "*" is first pressed followed by the numeric key for the indicated letter. Thus, for example, if the NAC character is a B, the "*" is pressed first followed by the "2" key pressed twice. As each of the numeric keys on a telephone keypad have multiple letters associated with them, the key is pressed a number of times to correspond to the position in the string of letters associated with the key. Thus, for example, the "2" key has letters A, B and C associated with it. Thus, if the character in the NAC string is an A, the "2" key is pressed once, if it is a B, it is pressed twice and if it is a C, it is pressed three times. Similarly, the "7" key has the indication for the letters P, R and S associated with it, however, letter Q could be added to the string in its natural position such that four letters, P, Q, R and S would be associated with the "7" key or it may be added to the end of the string such that one would press "7" once for P; press "7" twice for R, press "7" three times for S and four times for Q. Similarly, we add Z to "9" and press "9" four tiimes for Z. This type of implementation of the NAC with a tradition telephone set would likely be easier for the user to recall rather than having to remember the specified codes for each of the letters according to the Table of the NAC character and integer correspondences..

Using a NAC telephone set to call an old telephone number, it is generally preferred that it be set up to press the letter key "0", then input the number and press Enter.

The NAC telecommunication address codes and current telephone numbers can work compatibly and the old system may be allowed to gradually be replaced by the NAC system.

Using the NAC address codes, telephone cables, TV cables and Internet cables can be easily integrated into one telecommunication network, and their capacity and efficiency can be maximized.

Therefore, a NAC plus a user-defined string can be used for both local and international postal services, emergency services, delivery services, telephone and fax, cable TV and internet and other telecommunication services . The public can be released from managing continually increased addresses and codes.

THE NAC GEODETIC REFERENCE SYSTEM

As stated above, the Natural Area Coding System is a useful and powerful system that is capable of integrating almost all address code systems and makes all address related services much more efficient than current systems. Moreover, the system generates simple coordinates for geodetic points, simple and systematic codes for all areas of any size and any longitudinal and latitudinal spans on the earth surface and all three-dimensional regions of any size and any longitudinal, latitudinal and altitudinal spans, and possesses uses of all current geodetic and geographic grid and coordinate systems.

It will be a natural conclusion to use the Natural Area Coding System as the universal geographic and geodetic reference system which can greatly accelerate the exchange of all information related to the earth and the universe and help not only the professional people but also the whole population of the world to understand and use the information from the science and engineering related to the physical world, such as geology, geography, meteorology, oceanography, ecology, environmental science, space science, archeology, natural resources, mining and exploration, transportation and statistics.

SUMMARY OF THE NATURAL AREA CODING SYSTEM

The Natural Area Coding System is a multi-use geographic and geodetic coding system which can help people to manage continually increased addresses, codes and numbers, and supplies simple and systematic universal codes for all geodetic points, all areas on the earth and all regions in the universe. Due to so many advantages over other systems, the Natural Area Coding System will automatically become the universal geodetic reference system for geography, geology, oceanography, meteorology and astronomy and help people to record, retrieve, interpret, present and communicate geographic, geologic, ecological, oceanographic, meteorological and astronomic information. The world wide application of the system can greatly benefit every individual in the world.

While in the preferred embodiment described above, the character set utilizes 30 characters, namely the digits 0-9 and the consonants of the English alphabet, other character set sizes of from 26 to 36 could be utilized. The utilization of the 30 digits of the preferred embodiment provides a further advantage in that the possibility of generating strings in the NAC which would affront public morality or social customs is reduced as the strings would contain no vowels. It may also be possible to utilize a character set of 31 characters by adding the letter Y to the 30 character set. Such a character set would provide for a resolution of a NAC cell of 44 meters in the longitudinal direction and 22 meters in the latitudinal direction for a 4 character string. Other character sets utilizing 34 characters which would be the digits 0-9 and all the letters of the English alphabet with the exception of 0 and I could be utilized. Alternatively, the full 36 character set of all digits 0-9 and all the letters of the English alphabet could be utilized to provide a resolution of 24 meters by 12 meters for a 4 character string. As another alternative only the 26 letters of the English alphabet could be utilized. However, for the reasons set forth above, it is preferred that the character set be of only 30 characters as this has been found to provide the most flexibility.

The number of characters in each of the character strings can also be varied as described above to increase the resolution of coding system and desired application. For example, with the 30 character set of the preferred embodiment, 5 character strings would give a resolution of less than 2 meters by 1 meter at the earth's surface. However, for most applications, 4 character strings are to be preferred. Although various preferred embodiments of the present invention have been described herein in detail, it will be appreciated by those skilled in the art, that variations may be made thereto without departing from the spirit of the invention or the scope of the appended claims.

REFERENCE

[1] Decker, B.L., "World Geodetic System 1984." Proceedings of the Fourth International Geodetic Symposium on Satellite Positioning, Austin, Texas, April 28-May 2 , Vol. 1, p.69-92, 1986.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A Natural Area Coding System based upon the natural coordinates of longitude and latitude, the system comprising a character string of n characters to represent the longitude and a second character string of n characters to represent the latitude of a particular location, each of the characters in each of the strings being selected from one of a number of possible characters, the natural area code being obtained by the following method:

a) calculate the integers xi to x_n for the longitude and yi to y for the latitude as follows: LONG = Aⁿ*Longitude/360, LAT = A^m*Latitude/180

q=l,2, ..., n or m is the place number, where

Longitude=180+Longitude East OR 180-Longitude West or

Longitude=Longitude East OR 360-Longitude West or Longitude=180+Longitude West OR 180-Longitude East or Longitude=Longitude West OR 360-Longitude East and Latitude=90+Latitude North OR 90-Latitude South or Latitude=90+Latitude South OR 90-Latitude North

Nearest whole number of ( ) with xo=yo=0-5

F( ) = OR Llnteger part of ( ) with

q-1 ∑ sums the terms only when q>l, otherwise equals to zero. i«l

A is the number of characters in the character set. n and m are the number of characters in the longitude and latitude character string respectively; and b) substitute each of the integers in the integer string for the equivalent character from a specified character set to generate the natural area code for a location.

2. A Natural Area Coding System according to claim 1 wherein A is an integer of between 26 and 36 and m and n are integers independently selected from between 2 and 6.

3. A Natural Area Coding System according to claim 1 wherein A is 30, 31, 34 or 36 and m and n are 4.

4. A Natural Area Coding System according to claim 1 wherein A is 36 and m and n are 4.

5. A Natural Area Coding System according to claim 4 wherein the integers xi to X4 and yi to y in the integer strings are substituted for an equivalent character according to the following table of symbols:

6. A Natural Area Coding System according to claim 1 wherein A is 30 and m and n are 4.

7. A Natural Area Coding System according to claim 6 wherein the integers i to X and yi to y4 in the integer strings are substituted for an equivalent character according to the following table of symbols:

8. A Natural Area Coding System according to claim 1 in which the geodetic coding system also includes a character string of p characters for the altitude where the characters in the altitidue character string are obtained as follows:

ALT = AP* Arctan ((Altitude + R)/R)/90

where F( ), zn, A and q have the same meaning as in claim 1 and p is the number of characters in the altitude character string; is the distance from the earth center in km along the gravitational force line to the geoid surface and can be approximated by the earth radius at the location:

f = (a - b) /a ; e = 2*f - f² ;

N = a/sqrt d - e² * sin² (Latitude) ) ;

R = N*sqrt [l- e² * (2-e²) *sin² (Latitude) ]

where a is the semi-major earth axis (ellipsoid equatorial radius) equal to 6378.1370 km; b is the semi-minor earth axis (ellipsoid polar radius) equal to 6356.7523 km; sqrt () is the square root function; sin () and cos () are triangular functions; the symbol / is the division sign and the altitude string ZιZ2Z3...Z_p corresponds to the integers

9. A Natural Area Coding System according to claim 8 in which A is an integer of between 26 and 36 and m, n and p are integers independently selected from between 2 and 6.

10. A Natural Area Coding System according to claim 8 wherein A is 30, 31, 34 or 36 and m, n and p are 4.

11. A Natural Area Coding System according to claim 10 wherein A is 36.

12. A Natural Area Coding System according to claim 10 wherein A is 30 and m, n and p are 4.

13. A Natural Area Coding System according to claim 12 wherein the integers xi to X4, yi to y4 and z\ to Z4 in the integer strings are substituted for an equivalent character according to the following table of symbols:

14. A map of a region of the earth having grid lines printed thereon corresponding to the Natural Area Code of the region as determined according any one of claims 1 to 7.

15. A postal addressing system utilizing the natural area code of the address as determined according to any one of claims 1 to 7.

16. A postal addressing system according to claim 15 further including a third locally defined character string.

17. A telecommunications apparatus having a telecommunications address corresponding to the natural area code of the location of the telecommunications apparatus determined according to any one of claims 1 to 7.

18. A telecommunications apparatus according to claim 17 wherein the telecommunications address includes a third locally defined character string.

19. A telecommunications apparatus according to claim 17 or claim 18 wherein the apparatus further includes a means for addressing other telecommunications apparatus according to their telecommunications addresses.

20. A global positioning system unit having a display of the location of the unit wherein the display of the location of the global positioning system unit utilizes the Natural Area Coding System determined according to any one of claims 1 to 7.

21. A global positioning system unit according to claim 20 wherein the unit further includes a keyboard or keypad for inputting the character set of the Natural Area Coding System.

22. A geographic and geodetic information system and databsae having a geographic and geodetric information management system based upon the Natural Area Coding System according to any one of claims 1 to 7.

23. A mail sorting software program based on the postal addressing system according to claim 15 or 16.

24. An emergency address dispatching software program based on the Natural Area Coding System according to any one of claims 1 to 7.