In the

Domain Name System The Domain Name System (DNS) is a hierarchical and distributed naming system for computers, services, and other resources in the Internet or other Internet Protocol (IP) networks. It associates various information with domain names assigned to ...

, a LOC record (experimental ) is a means for expressing geographic location information for a

domain name A domain name is a string that identifies a realm of administrative autonomy, authority or control within the Internet. Domain names are often used to identify services provided through the Internet, such as websites, email services and more. As ...

. It contains

WGS84 The World Geodetic System (WGS) is a standard used in cartography, geodesy, and satellite navigation including GPS. The current version, WGS 84, defines an Earth-centered, Earth-fixed coordinate system and a geodetic datum, and also descr ...

Latitude In geography, latitude is a coordinate that specifies the north– south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from –90° at the south pole to 90° at the north pol ...

Longitude Longitude (, ) is a geographic coordinate that specifies the east–west position of a point on the surface of the Earth, or another celestial body. It is an angular measurement, usually expressed in degrees and denoted by the Greek letter l ...

and

Altitude Altitude or height (also sometimes known as depth) is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The exact definition and reference datum varies according to the context ...

(

ellipsoidal height Geodetic coordinates are a type of curvilinear orthogonal coordinate system used in geodesy based on a ''reference ellipsoid''. They include geodetic latitude (north/south) , ''longitude'' (east/west) , and ellipsoidal height (also known as geod ...

) information together with host/

subnet A subnetwork or subnet is a logical subdivision of an IP network. Updated by RFC 6918. The practice of dividing a network into two or more networks is called subnetting. Computers that belong to the same subnet are addressed with an identical ...

physical size and location accuracy. This information can be queried by other computers connected to the Internet.

Record format

The LOC record is expressed in a master file in the following format:

   LOC ( d1  1_[s1__d2_[m2_[s2.html"_;"title="1.html"_;"title="1_[s1">1_[s1__d2_[m2_[s2">1.html"_;"title="1_[s1">1_[s1__d2_[m2_[s2
_____________________________alt["m".html" ;"title="1">1_[s1__d2_[m2_[s2.html" ;"title="1.html" ;"title="1 [s1">1 [s1  d2 [m2 [s2">1.html" ;"title="1 [s1">1 [s1  d2 [m2 [s2
                             alt["m"">1">1_[s1__d2_[m2_[s2.html" ;"title="1.html" ;"title="1 [s1">1 [s1  d2 [m2 [s2">1.html" ;"title="1 [s1">1 [s1  d2 [m2 [s2
                             alt["m"[siz["m"] [hp["m"]
                            [vp["m"  )

(The parentheses are used for multi-line data as specified in RFC 1035, section 5.1.) where:

    d1:     [0 .. 90]            (degrees latitude)
    d2:       .. 180          (degrees longitude)
    m1, m2:   .. 59           (minutes latitude/longitude)
    s1, s2:   .. 59.999       (seconds latitude/longitude)
    alt:     100000.00 .. 42849672.95BY .01 (altitude in meters)
    siz, hp, vp:   .. 90000000.00(size/precision in meters)

An example DNS LOC resource record

* statdns.net for the

coordinates In geometry, a coordinate system is a system that uses one or more numbers, or coordinates, to uniquely determine the position of the points or other geometric elements on a manifold such as Euclidean space. The order of the coordinates is sig ...

LOC record statdns.net.   IN LOC   52 22 23.000 N 4 53 32.000 E -2.00m 0.00m 10000m 10m

Altitude for Geosynchronous Earth Satellites

The altitude range provides the following: * DNS altitude range 100000.00 .. 42849672.95 This range can be easily stored in 4 bytes. * Maximum altitude is 42,849.67295 km. Which is large enough to store the altitude of a circular geosynchronous orbit (i.e. approximately 35,790 km above mean sea level). * Maximum depth of 100 km below earth surface (approximated by the

reference ellipsoid An Earth ellipsoid or Earth spheroid is a mathematical figure approximating the Earth's form, used as a reference frame for computations in geodesy, astronomy, and the geosciences. Various different ellipsoids have been used as approximations ...

UK Postcode to DNS LOC record using find.me.uk

You can look up the LOC record for any UK postcode, e.g.: $ dig loc SW1A2AA.find.me.uk SW1A2AA.find.me.uk. 2592000 IN LOC 51 30 12.748 N 0 7 39.612 W 0.00

References

* Wikipedia:WikiProject Geographical coordinates The Wikipedia location resource.
Sites supporting DNS LOC
* - How latitude and longitude are stored in a DNS record. * Chapter 3.4.2: Text/directory MIME type GEO * Section 6.5.2: GEO (obsoleted , updated by ) {{DEFAULTSORT:Loc Record DNS record types Internet geolocation

Record format

An example DNS LOC resource record

Altitude for Geosynchronous Earth Satellites

UK Postcode to DNS LOC record using find.me.uk

See also

References