science

LOC record

LOC record is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand LOC record rather than just read about it. In short: In the Domain Name System, a LOC record (experimental RFC 1876) 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.

Key takeaways

LOC record belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect LOC record to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of LOC record from memory before moving on to harder problems.

Reference excerpt

In the Domain Name System, a LOC record (experimental RFC 1876) 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:

⟨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)

An example DNS LOC resource record statdns.net for the coordinates: 52°22′23″N 4°53′32″E

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 RFC 1876 - How latitude and longitude are stored in a DNS record. RFC 2426 Chapter 3.4.2: Text/directory MIME type GEO RFC 6350 Section 6.5.2: GEO (obsoleted RFC 2426, updated by RFC 6868)

Worked examples

Example 1 — a first encounter with LOC record

Start with the simplest possible case. Write down what LOC record claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to LOC record before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about LOC record ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of LOC record

In research: LOC record appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses LOC record in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: LOC record is common in secondary-school and first-year university syllabi. It links to neighbouring topics DNS record types, Internet geolocation, so understanding it makes those chapters shorter.
In everyday life: Look for LOC record outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study LOC record in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what LOC record means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain LOC record out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is LOC record in simple terms?

Why does LOC record matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study LOC record?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on LOC record.