LOC record

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In the Domain Name System, a LOC record (RFC 1876) is a means for expressing geographic location information for a domain name.

It contains WGS84 Latitude, Longitude and Altitude information together with host/subnet physical size and location accuracy. This information can be queried by other computers connected to the internet.

Contents

[edit] Record format

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

<owner> <TTL> <class> 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)

[edit] An example DNS LOC resource record

[edit] 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.

[edit] See also

[edit] References

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