LOC record

Template:More footnotes In the Domain Name System, a LOC record (experimental Template:IETF RFC) 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:

Template:Angbr Template:Angbr Template:Angbr 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:

    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)

An example DNS LOC resource record

• statdns.net for the coordinates: Template:Coord

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 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
• Template:IETF RFC - How latitude and longitude are stored in a DNS record.
• Template:IETF RFC Chapter 3.4.2: Text/directory MIME type GEO
• Template:IETF RFC Section 6.5.2: GEO (obsoleted Template:IETF RFC, updated by Template:IETF RFC)