ANSI INCITS 61-1986 Information Systems - Representation of Geographic Point Locations for Information Interchange.pdf

1、ADOPTED FOR USE BYTHE FEDERAL GOVERNMENTSEE NOTICE ON INSIDEANSI INCITS 61-1986 (R2002)(formerly ANSI X3.61-1986 (R1997) for Information Systems -Representation ofGeographic Point Locationsfor Information InterchangePUB 70-1This standard has been adopted for Federal Government use. Details concernin

2、g its use within the Federal Government are contained in Federal Information Processing Standards Publication 153, Programmers Hierarchical interactive Graphics System (PHIGS). For a complete list of the publications available in the Federal Information Processing Standards Series, write to the Stan

3、dards Processing Coordinator (ADP), National Institute of Standards and Tech- nology, Gaithersburg, MD 20899. AmericanNationalStandardApproval of an American National Standard requires review by ANSI that therequirements for due process, consensus, and other criteria for approval havebeen met by the

4、 standards developer.Consensus is established when, in the judgment of the ANSI Board of StandardsReview, substantial agreement has been reached by directly and materiallyaffected interests. Substantial agreement means much more than a simplemajority, but not necessarily unanimity. Consensus require

5、s that all views andobjections be considered, and that a concerted effort be made toward theirresolution.The use of American National Standards is completely voluntary; their existencedoes not in any respect preclude anyone, whether he has approved the standardsor not, from manufacturing, marketing,

6、 purchasing, or using products, processes,or procedures not conforming to the standards.The American National Standards Institute does not develop standards and will inno circumstances give an interpretation of any American National Standard.Moreover, no person shall have the right or authority to i

7、ssue an interpretation ofan American National Standard in the name of the American National StandardsInstitute. Requests for interpretations should be addressed to the secretariat orsponsor whose name appears on the title page of this standard.CAUTION NOTICE: This American National Standard may be r

8、evised orwithdrawn at any time. The procedures of the American National StandardsInstitute require that action be taken periodically to reaffirm, revise, or withdrawthis standard. Purchasers of American National Standards may receive currentinformation on all standards by calling or writing the Amer

9、ican National StandardsInstitute.Published byAmerican National Standards Institute11 West 42nd Street, New York, New York 10036Copyright 1986 by Information Technology Industry Council (ITI)All rights reserved.No part of this publication may be reproduced in anyform, in an electronic retrieval syste

10、m or otherwise,without prior written permission of ITI, 1250 Eye Street NW,Washington, DC 20005.Printed in the United States of AmericaANSI X3.61 -1986 Revision of ANSI X3.61 -1978 American National Standard for Information Systems - Representation of Geographic Point Locations for Information Inter

11、change Secretariat Computer and Business Equipment Manufacturers Association Approved June 23, 1986 American National Standards institute, Inc Foreword (This Foreword is not part of American National Standard X3 61-1986 ) This standard provides uniform formats for representing geographic point locat

12、ion data in digital form for interchange between and among data systems and to enhance man-to-man communication. Geographic point location refers to the use of a coordinate system to define the position of a point which may be on, above, or below the earths surface. Suggestions for the improvement o

13、f this standard will be welcome. They should be sent to the Computer and Business Equipment Manufacturers Association, 311 First Street, NW, Suite 500, Washington, DC 20001. This standard was processed and approved for submittal to ANSI by Accredited Standards Committee on Information Processing Sys

14、tems, X3. Committee appro- val of the standard does not necessarily imply that all members voted for its appro- val. At the time it approved this standard, the X3 Committee had the following members: Edward Lohse, Chair Richard Gibson, Vice-Chair Catherine A. Kachurik, Administrative Secretary Organ

15、ization Represented American Express . . . . . . . . . . . . . . . . . . . . . . American Library Association . . . . . . . . . . . . . American Nuclear Society . . . . . . . . . . . . . . . . . AMP Incorporated . . . . . . . . . . . . . . . . . . . . . . . Association for Computing Machinery . . .

16、. . . Association of the Institute for Certification of Computer Professionals . . . AT similarly, when a decimal fraction of a minute is used, no seconds may be expressed. 2.1.2 Use of Separators. Separators are permissi- ble to enhance understanding of the contents of data files. When separators a

17、re used, the following guidelines are to be followed: (1) Separators between Latitude and Longitude: Latitude shall be separated from longitude by a comma or a blank. No other symbol shall be used as a separator between these items. (2) Separators between Elements within Latitude or Longitude: No se

18、parators shall be used other than the decimal point, as specified in 2.1.3 through 2.1.6. It is recognized that degrees, minutes, and seconds are conventionally denoted and separated in textual material by using superscripted symbols. For this standard, such designations have not been included as pe

19、rmissible primarily because many data processing machines cannot recognize or re- produce the conventional superscripts. 2.1.3 Representation of Degrees. For both lati- tude and longitude, when a decimal fraction of a degree is specified, it shall be separated from the whole number of degrees by a d

20、ecimal point and expressed numerically to the number of places required by the desired precision. 2.1.3.1 Latitude. The degree of latitude shall be represented by a decimal number ranging from 0 through 90. For all values less than 10, a leading zero or blank shall be given (for example, 01, 15, or

21、b3 where b represents a blank or space). All records in the same file shall use either leading blanks or zeros, but not both. 2.1.3.2 Longitude. The degrees of longitude shall be represented by a decimal number ranging from 0 through 180. For values less than 100, lead- ing zero(s) or blanks shall b

22、e given (for example, 001,027, b18, or bb3). All records in the same file shall use either leading blanks or zeros, but not both. 2.1.4 Representation of Minutes. For both lati- tude and longitude, the minutes shall be represent- ed by a two-digit decimal number ranging from 00 through 59. For value

23、s less than 10, a leading zero shall be given. When a location is indicated by degrees, minutes, and decimal fractions of a min- ute, the decimal fraction shall be separated from the whole number of minutes by a decimal point and expressed numerically to the number of places required by the desired

24、precision. 2.1.5 Representation of Seconds. For both lati- tude and longitude, seconds shall be represented by a two-digit decimal number ranging from 00 through 59. For values less than 10, a leading zero shall be given. When a location is indicated by degrees, minutes, seconds, and decimal fractio

25、ns of a second, the decimal fraction shall be separated from the whole number of seconds by a decimal point and expressed numerically to the number of places required by the desired precision. 2.1.6 Representation of Radians. Another way of representing latitude and longitude is by converting degree

26、s to radians. One degree is equal to 0.017453292519943 radians. 2.1.6.1 Latitude. Radians of latitude shall be expressed as a one-digit number (0 or 1) followed by a decimal fraction. The maximum value of lati- tude in radians should not exceed one-half pi (1.570 796 327). See 2.1.8 for a discussion

27、 of the precision. 2.1.6.2 Longitude. Radians of longitude shall be expressed as a one-digit number (0, 1, 2, or 3) followed by a decimal fraction. The maximum value of longitude should not exceed pi (3.141 592 654). See 2.1.8 for a discussion of the necessary precision. 2.1.7 Representation of Hemi

28、spheric Informa- tion. Two methods of representing the hemisphere are permitted. If the alternate representation is used, that information must be included in the documentation accompanying the interchange. With the exception of radian values, latitudes north of the equator may be specified by an up

29、per- case “N” immediately following the last digit for latitude. Latitudes south of the equator may be designated by an uppercase “S” immediately follow- ing the last digit for latitude. A point on the equa- tor shall be assigned to the Northern Hemisphere. With the exception of radian values, longi

30、tudes east of the prime meridian may be specified by an uppercase “E” immediately following the last digit for longitude. Longitudes west of the prime meridi- an may be designated by an uppercase “W” imme- diately following the last digit for longitude. A point on the prime meridian shall be assigne

31、d to the Eastern Hemisphere. A point on the 180th meridian shall be assigned to the Western Hemisphere. 7 . AMERICAN NATIONAL STANDARD X3 61-1986 All radian values shall use the alternate represen- tation of hemispheric information, which is as follows: Latitudes north of the equator may be specifie

32、d by a plus sign (+) immediately preceding the digits designating degrees. Latitudes south of the equator may be designated by a minus sign (-) preceding the digits designating degrees. A point on the equa- tor shall be assigned to the Northern Hemisphere. Longitudes east of the prime meridian may b

33、e spec- ified by a plus sign (I-) immediately preceding the digits designating degrees of longitude. Longitudes west of the meridian may be designated by a minus sign (-) preceding the digits designating degrees. A point on the prime meridian shall be assigned to the Eastern Hemisphere. A point on t

34、he 180th meridian shall be assigned to the Western Hemisphere. 2.1.8 Precision. A point can be represented at various levels of precision, as illustrated in the numbered examples below. (Separation is shown by using a comma, with the understanding that a space (blank) could have been used instead of

35、 a comma.) The number of digits does not necessarily imply precision. (I) Degrees and decimal fractions of a degree (2) Degrees and minutes (3) Degrees, minutes, and decimal frac- tions of a minute (4) Degrees, minutes, and seconds (5) Degrees, minutes, seconds, and deci- mal fractions of a second (

36、6) Radians 40 20364N,O75 0042OW or +40.20364,-075.00420 4012N,07500W or +40 I2,-07500 40 I2 22N,07500 25 W or $4012 22,-b7500.25 40121311,0750015W or +401213,-b750015 401213 IN,0750015 1W or f401213 I,-b750015 1 +o 7017,-l 3091 For longitude at the equator, and for latitude anywhere on the earth, th

37、e location of a point to the level of precision of 0.01 foot (0.003 meter) on the face of the earth corresponds approximately to angular values (on a great circle) of 0.00000000048 radian, 0.000000028 degree, 0.0000017 minute, or 0.00010 second. This accuracy is the preferred representation and is a

38、ccomplished by use of the maximum precision in this standard. Using these values, the preceding examples of lat- itude and longitude at this level of precision are as follows. The b represents a blank space. (I) Degrees and decimal 4020364255N,07500420039W fractions of a degree or +40.20364255,-b75

39、00420039 (3) Degrees, minutes, and decimal 4012 218553N,07500 252023W or f4012 218553,-b7500 252023 fractions of a minute (5) Degrees, minutes, seconds, and decimal fractions of a second (6) Radians 401213.1132N,0750015.1214W or +401213 1132,-b750015 1214 +0 7016859338,-1.3090702496 The number of de

40、cimal places to which any representation of latitude or longitude is carried must, of course, depend on the users requirements, the accuracy of measuring instruments, and similar factors. 2.2 Representations for Universal Transverse Mer- cator System (UTM). The Universal Transverse Mercator (UTM) Sy

41、stem provides rectangular coordinates that may be used to indicate locations of points on the surface of the earth. The unit of measure is the meter. A point is located by specify- ing a hemispheric indicator, a zone number, an easting value, and a northing value. UTM is designed for world use betwe

42、en 80 degrees south latitude, and 84 degrees north lati- tude. The globe is divided into narrow zones, 6 degrees of longitude in width, starting at the 180 degree meridian of longitude and progressing east- ward. The zones are numbered 1 through 60. Each zone has, as its east and west limits, a meri

43、dian of longitude. Each zone also has a critical meridian passing through the center of the zone. Table 1 demonstrates the coverage and central meridian of each zone. A value of 500,000 meters is assigned to the cen- tral meridian of each zone in order to avoid nega- tive numbers at the west edge of

44、 the zone. The values increase from west to east. For north-south values in the Northern Hemisphere, the equator is assigned 0 meters, and the numbers increase toward the North Pole. In the Southern Hemisphere, the equator has an implied value of 10,000,OOO meters and the numbers decrease toward the

45、 South Pole. The location of any point within a zone is given in relation to the central meridian within that zone and the equator. A points north-south location is obtained by either adding or subtracting the points distance north or south of the equator. Similarly, a points east-west location is o

46、btained by either adding or subtracting the points distance east or west of the central meridian. A point on the equator, if not otherwise speci- fied, is assigned a default value of zero for its northing and is treated as if it were in the Northern Hemisphere. The default zone assignment for a poin

47、t on a boundary meridian is the zone to the east of the point. 8 AMERICAN NATIONAL STANDARD X3 61-1986 Table 1 Universal Transverse Mercator Zone Locations and Central Meridians Zone 01 02 03 04 05 06 01 08 09 10 II 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Central Meridian 117W 17lW

48、165W 159w 153w 147w 14lW 135w 129W 123W 117w IllW 105w 099w 093w 087W 08lW 075w 069W 063W 057w 05lW 045w 039w 033w 027W 02lW 015w 009w 003w Range Zone 18OW-174w 31 174W-168W 32 168W-162W 33 162W-156W 34 156Wm15OW 35 15OWl44W 36 144w-l38W 31 138W-132W 38 132W-126W 39 126W-12OW 40 12OW-114W 41 114W-IO

49、SW 42 108w-102w 43 102WmO96W 44 096W-09OW 45 09OW-084W 46 084W-078W 47 078W-072W 48 072W-066W 49 066W-06OW 50 06OWmO54W 51 054WmO48W 52 048W-042W 53 042W-036W 54 036W-03OW 55 03OW-024W 56 024W-018W 57 018W-012W 58 012W-006W 59 006W-OOOE 60 Central Meridian 003E 009E OISE 021E 027E 033E 039E 045E 051E 057E 063E 069E 075E 081E 087E 093E 099E 105E 1llE 117E 123E 129E 135E 141E 147E 153E 159E 165E 171E 177E Range OOOE-006E 006E-0 12E 012E-018E 018E-024E 024Em030E 030E-036E 036E-042E 042E-048E 048E-054E 054E-060E 060E-066E 066Em072E 072E-078E 078E-084E 084E-090E 090E-096E 096E-102E