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ISO 6709

December 02, 2023

ISO 6709, Standard representation of geographic point location by coordinates, is the international standard for representation of latitude, longitude and altitude for geographic point locations.

The first edition (ISO 6709:1983) was developed by ISO/IEC JTC 1/SC 32. Later the standard was transferred to ISO/TC211, Geographic information/Geomatics in 2001. The committee completely revised the second edition (ISO 6709:2008). There was a short technical corrigendum (ISO 6709:2008/Cor 1:2009) released in 2009.[1] The third edition ISO 6709:2022 was published in 2022.[2]

The second edition consists of a main part and eight annexes (Annexes A through H). The main part and Annexes A and C give encoding-independent general rules to define items to specify geographic point(s). Annex D suggests a display style for human interface. Annexes F and G suggest styles of XML expression. Annex H suggests string expression, which supersedes the first edition of the standard.

General rules edit

Items edit

A geographical point is specified by the following four items:

  • First horizontal position coordinate (ϕ or y), such as latitude (negative number south of equator and positive north of equator)
  • Second horizontal coordinate (λ or x), such as longitude (negative values west of Prime Meridian and positive values east of Prime Meridian)
  • Vertical coordinate, i.e. height or depth (optional)
  • Identification of coordinate reference system (CRS) (optional)

The first three items are numerical values called coordinates. The CRS gives the relationship between the coordinates and a point on the earth. The identification of CRS could be a full description of properties defined in ISO 19111; only an identifier given by some registry (such as EPSG) is used in most cases, since only such identification is enough for most information exchange purposes.

Order, sign, and units edit

Order, positive direction, and units of coordinates are supposed to be defined by the CRS. When CRS identification is missing, the data must be interpreted by the following conventions:

  • Latitude comes before longitude
  • North latitude is positive
  • East longitude is positive
  • Fraction of degrees (decimal degrees) is preferred in digital data exchange, while sexagesimal notation is tolerated for compatibility

There is no such interpretation rule for vertical coordinates.

Representation at the human interface (Annex D) edit

When there is no guideline given from the user community, the following styles are suggested:

  1. Coordinate values (latitude, longitude, and altitude) should be delimited by spaces.
  2. The decimal point is a part of the value, thus must usually be configured by the operating system.[a]
  3. Multiple locations should be represented by multiple lines.
  4. Latitude and longitude should be displayed by sexagesimal fractions (i.e. minutes and seconds).
  5. When minutes and seconds are less than ten, leading zeroes should be shown.
  6. Degree, minutes and seconds should be followed by the symbols ° (U+00B0), ′ (U+2032), and ″ (U+2033), without spaces between the number and symbol.
  7. North and south latitudes should be indicated by N and S following immediately after the digits.
  8. East and west longitudes should be indicated by E and W following immediately after the digits.
  9. Units of elevation or depth should be given by symbols, immediately after the digits.[b]
  10. Elevation below zero-level reference or depth above reference level should be indicated by a minus sign − (U+2212).

Examples:

  • 50°40′46.461″N 95°48′26.533″W 123.45m
  • 50°03′46.461″S 125°48′26.533″E 978.90m

The standard does not specify how coordinates at the equator, prime meridian or antimeridian should be written.

XML representation (Annex F) edit

The XML representation based on the conceptual model of Annex C uses XML namespace http://www.isotc211.org/2006/gpl[permanent dead link]. However, there is no published XML schema at the time of writing (August 2011). 

<gpl:GPL_CoordinateTuple xmlns:gpl="http://www.isotc211.org/gpl">  <gpl:tuple srsName="urn:ogc:def:crs:EPSG:6.6:4326">  35.89421911 139.94637467  </gpl:tuple> </gpl:GPL_CoordinateTuple>

String expression (Annex H) edit

A string expression of a point consists of latitude, longitude, height or depth, CRS identifier, and trailing solidus (/) without any delimiting character. When height or depth is used, there must be CRS identifier.[c]

Latitude edit

Latitude is a number preceded by a sign character. A plus sign (+) denotes northern hemisphere or the equator, and a minus sign (-) denotes southern hemisphere.[d]

The integer part of the number is a fixed length. The number of digits in that part indicates the units, thus leading zero(es) must be filled when necessary. The fractional part must have the appropriate number of digits to represent the required precision of the coordinate.

num. digits units format example
2 deg ±DD.D +40.20361
4 deg, min ±DDMM.M +4012.22
6 deg, min, sec ±DDMMSS.S +401213.1

Longitude edit

Longitude is a number preceded by a sign character. A plus sign (+) denotes east longitude or the prime meridian, and a minus sign (-) denotes west longitude or 180° meridian (opposite of the prime meridian).[e]

Rules about the number of digits are the same as for latitude.

num. digits units format example
3 deg ±DDD.D -075.00417
5 deg, min ±DDDMM.M -07500.25
7 deg, min, sec ±DDDMMSS.S -0750015.1

Height or depth edit

Further information: Vertical position
  • When height or depth is present, CRS identifier must follow.
  • Positive direction and units are defined by CRS.[f]
  • Negative number does not necessarily mean position below reference level.
  • Positive is up for height, down for depth.

CRS identifier edit

Further information: SRID

The CRS identifier begins with "CRS". There are three styles:

  1. When a registry provides online resolver, CRS<url>
  2. When a registry is offline, CRSregistry:crsid
  3. When the data creator provides full definition of CRS using ISO 19111, CRS<CRSID>

The example of original Annex H always use "CRSWGS_84".

Examples edit

See also edit

Notes edit

  1. ^ Probably the intention is that the locale environment should not be overridden.
  2. ^ This is different from SI style guides.[disputed – discuss]
  3. ^ Height without CRS identifier was allowed in the first edition, but not today. Ending with longitude is still allowed.
  4. ^ Annex H allows letters N and S as sign characters, but gives no examples.
  5. ^ Annex H allows letters E and W as sign characters, but gives no examples.
  6. ^ This is different from the 1983 edition.

References edit

  1. ^ "ISO 6709:2008/Cor 1:2009 -". ISO. Retrieved 8 June 2016.
  2. ^ "ISO 6709:2022". www.iso.org. Retrieved 26 May 2023.

External links edit

Standards edit

  • Catalogue entry for ISO 6709:2008
  • Profile by W3C GeoXG

Implementations edit

  • Point Location 6709 - an open-source Java parser and formatter
  • Point Location 6709 - an open-source JavaScript implementation
  • C# Implementation at Codeplex
  • Objective-C Implementation

December 02, 2023
6709, this, article, relies, largely, entirely, single, source, relevant, discussion, found, talk, page, please, help, improve, this, article, introducing, citations, additional, sources, find, sources, news, newspapers, books, scholar, jstor, july, 2020, this. This article relies largely or entirely on a single source Relevant discussion may be found on the talk page Please help improve this article by introducing citations to additional sources Find sources ISO 6709 news newspapers books scholar JSTOR July 2020 This article needs to be updated The reason given is was written before current third edition of the standard Please help update this article to reflect recent events or newly available information May 2023 ISO 6709 Standard representation of geographic point location by coordinates is the international standard for representation of latitude longitude and altitude for geographic point locations The first edition ISO 6709 1983 was developed by ISO IEC JTC 1 SC 32 Later the standard was transferred to ISO TC211 Geographic information Geomatics in 2001 The committee completely revised the second edition ISO 6709 2008 There was a short technical corrigendum ISO 6709 2008 Cor 1 2009 released in 2009 1 The third edition ISO 6709 2022 was published in 2022 2 The second edition consists of a main part and eight annexes Annexes A through H The main part and Annexes A and C give encoding independent general rules to define items to specify geographic point s Annex D suggests a display style for human interface Annexes F and G suggest styles of XML expression Annex H suggests string expression which supersedes the first edition of the standard Contents 1 General rules 1 1 Items 1 2 Order sign and units 2 Representation at the human interface Annex D 3 XML representation Annex F 4 String expression Annex H 4 1 Latitude 4 2 Longitude 4 3 Height or depth 4 4 CRS identifier 4 5 Examples 5 See also 6 Notes 7 References 8 External links 8 1 Standards 8 2 ImplementationsGeneral rules editItems edit A geographical point is specified by the following four items First horizontal position coordinate ϕ or y such as latitude negative number south of equator and positive north of equator Second horizontal coordinate l or x such as longitude negative values west of Prime Meridian and positive values east of Prime Meridian Vertical coordinate i e height or depth optional Identification of coordinate reference system CRS optional The first three items are numerical values called coordinates The CRS gives the relationship between the coordinates and a point on the earth The identification of CRS could be a full description of properties defined in ISO 19111 only an identifier given by some registry such as EPSG is used in most cases since only such identification is enough for most information exchange purposes Order sign and units edit Order positive direction and units of coordinates are supposed to be defined by the CRS When CRS identification is missing the data must be interpreted by the following conventions Latitude comes before longitude North latitude is positive East longitude is positive Fraction of degrees decimal degrees is preferred in digital data exchange while sexagesimal notation is tolerated for compatibilityThere is no such interpretation rule for vertical coordinates Representation at the human interface Annex D editWhen there is no guideline given from the user community the following styles are suggested Coordinate values latitude longitude and altitude should be delimited by spaces The decimal point is a part of the value thus must usually be configured by the operating system a Multiple locations should be represented by multiple lines Latitude and longitude should be displayed by sexagesimal fractions i e minutes and seconds When minutes and seconds are less than ten leading zeroes should be shown Degree minutes and seconds should be followed by the symbols U 00B0 U 2032 and U 2033 without spaces between the number and symbol North and south latitudes should be indicated by N and S following immediately after the digits East and west longitudes should be indicated by E and W following immediately after the digits Units of elevation or depth should be given by symbols immediately after the digits b Elevation below zero level reference or depth above reference level should be indicated by a minus sign U 2212 Examples 50 40 46 461 N 95 48 26 533 W 123 45m 50 03 46 461 S 125 48 26 533 E 978 90mThe standard does not specify how coordinates at the equator prime meridian or antimeridian should be written XML representation Annex F editThe XML representation based on the conceptual model of Annex C uses XML namespace http www isotc211 org 2006 gpl permanent dead link However there is no published XML schema at the time of writing August 2011 lt gpl GPL CoordinateTuple xmlns gpl http www isotc211 org gpl gt lt gpl tuple srsName urn ogc def crs EPSG 6 6 4326 gt 35 89421911 139 94637467 lt gpl tuple gt lt gpl GPL CoordinateTuple gt String expression Annex H editA string expression of a point consists of latitude longitude height or depth CRS identifier and trailing solidus without any delimiting character When height or depth is used there must be CRS identifier c Latitude edit Latitude is a number preceded by a sign character A plus sign denotes northern hemisphere or the equator and a minus sign denotes southern hemisphere d The integer part of the number is a fixed length The number of digits in that part indicates the units thus leading zero es must be filled when necessary The fractional part must have the appropriate number of digits to represent the required precision of the coordinate num digits units format example2 deg DD D 40 203614 deg min DDMM M 4012 226 deg min sec DDMMSS S 401213 1Longitude edit Longitude is a number preceded by a sign character A plus sign denotes east longitude or the prime meridian and a minus sign denotes west longitude or 180 meridian opposite of the prime meridian e Rules about the number of digits are the same as for latitude num digits units format example3 deg DDD D 075 004175 deg min DDDMM M 07500 257 deg min sec DDDMMSS S 0750015 1Height or depth edit Further information Vertical position When height or depth is present CRS identifier must follow Positive direction and units are defined by CRS f Negative number does not necessarily mean position below reference level Positive is up for height down for depth CRS identifier edit Further information SRID The CRS identifier begins with CRS There are three styles When a registry provides online resolver CRS lt url gt When a registry is offline CRSregistry crsid When the data creator provides full definition of CRS using ISO 19111 CRS lt CRSID gt The example of original Annex H always use CRSWGS 84 Examples edit Atlantic Ocean 00 025 France 46 002 Paris 48 52 002 20 Eiffel Tower 48 8577 002 295 Mount Everest 27 5916 086 5640 8850CRSWGS 84 North Pole 90 000 Pacific Ocean 00 160 South Pole 90 000 2800CRSWGS 84 United States 38 097 New York City 40 75 074 00 Statue of Liberty 40 6894 074 0447 See also editList of geodesic geocoding systems LOC record Geo microformat Notes edit Probably the intention is that the locale environment should not be overridden This is different from SI style guides disputed discuss Height without CRS identifier was allowed in the first edition but not today Ending with longitude is still allowed Annex H allows letters N and S as sign characters but gives no examples Annex H allows letters E and W as sign characters but gives no examples This is different from the 1983 edition References edit ISO 6709 2008 Cor 1 2009 ISO Retrieved 8 June 2016 ISO 6709 2022 www iso org Retrieved 26 May 2023 External links editStandards edit Catalogue entry for ISO 6709 2008 final draft of ISO 6709 2008 Profile by W3C GeoXGImplementations edit Point Location 6709 an open source Java parser and formatter Point Location 6709 an open source JavaScript implementation C Implementation at Codeplex Objective C Implementation Retrieved from https en wikipedia org w index php title ISO 6709 amp oldid 1157956213, wikipedia, wiki, book, books, library,

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