In the Domain Name System, a LOC record (experimental ) is a means for expressing geographic location information for a domain name.

It contains WGS84 Latitude, Longitude and Altitude (ellipsoidal height) information together with host/subnet 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 [m1 [s1]] {"N"|"S"} d2 [m2 [s2]]

{"E"|"W"} 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:

<pre>

d1: [0 .. 90] (degrees latitude)

d2: [0 .. 180] (degrees longitude)

m1, m2: [0 .. 59] (minutes latitude/longitude)

s1, s2: [0 .. 59.999] (seconds latitude/longitude)

alt: [-100000.00 .. 42849672.95] BY .01 (altitude in meters)

siz, hp, vp: [0 .. 90000000.00] (size/precision in meters)

</pre>

An example DNS LOC resource record

  • statdns.net for the coordinates:

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&nbsp;km. Which is large enough to store the altitude of a circular geosynchronous orbit (i.e. approximately 35,790&nbsp;km above mean sea level).
  • Maximum depth of 100&nbsp;km below earth surface (approximated by the WGS84 reference ellipsoid).

See also

  • List of DNS record types
  • Geo (microformat)
  • Geolocation
  • Geolocation API
  • ICBM address
  • ISO 6709

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 )