meridian angle: meaning, definition, pronunciation and examples
Very Low / TechnicalFormal / Technical / Scientific
Quick answer
What does “meridian angle” mean?
The angular distance, measured east or west from a reference meridian (typically the observer's celestial meridian or the Greenwich meridian), to the position of a celestial body or point.
Audio
Pronunciation
Definition
Meaning and Definition
The angular distance, measured east or west from a reference meridian (typically the observer's celestial meridian or the Greenwich meridian), to the position of a celestial body or point.
In navigation, astronomy, and geodesy, the arc of the celestial equator or the angle at the celestial pole between the reference meridian and the hour circle of a celestial body, expressed in degrees, hours, or arc-minutes. It forms part of the coordinate system for locating objects in the sky or on the Earth's surface.
Dialectal Variation
British vs American Usage
Differences
No significant lexical or semantic differences exist. Spelling conventions (e.g., 'angle' vs. 'angler') do not apply. Both regions use identical terminology in technical literature.
Connotations
Purely technical, with no cultural or regional connotations beyond its scientific definition.
Frequency
Extremely rare outside professional navigation (nautical/aviation), astronomy, surveying, and geodesy. Frequency is identical in both dialects within those fields.
Grammar
How to Use “meridian angle” in a Sentence
[calculate/determine/measure] + [the/a] + meridian angle + [of + NOUN PHRASE (e.g., the star, the celestial body)]The meridian angle + [is/was] + [measured/calculated] + [east/west] + [from + NOUN PHRASE (e.g., the Greenwich meridian)]Vocabulary
Collocations
Examples
Examples of “meridian angle” in a Sentence
verb
British English
- [Not applicable as a verb]
American English
- [Not applicable as a verb]
adverb
British English
- [Not applicable as an adverb]
American English
- [Not applicable as an adverb]
adjective
British English
- The meridian-angle calculation is critical for the fix.
- They used a meridian-angle table from the nautical almanac.
American English
- The meridian-angle data was entered into the GPS backup system.
- A meridian-angle correction must be applied.
Usage
Meaning in Context
Business
Not used.
Academic
Used in university-level courses in astronomy, geomatics, and navigation. Found in specialised textbooks and research papers.
Everyday
Virtually never used in general conversation.
Technical
Core term in celestial navigation for calculating a line of position. Used by sailors, pilots (historically), surveyors, and astronomers to determine location or track celestial objects.
Vocabulary
Synonyms of “meridian angle”
Strong
Neutral
Weak
Vocabulary
Antonyms of “meridian angle”
Watch out
Common Mistakes When Using “meridian angle”
- Using 'meridian angle' to refer to the altitude or elevation of a celestial body (a vertical angle).
- Confusing 'east' and 'west' when specifying the direction of the measurement, which is crucial for calculations.
- Omitting the reference meridian (local or Greenwich), making the term ambiguous.
FAQ
Frequently Asked Questions
They are related concepts but not identical. Longitude is a fixed geographic coordinate. A meridian angle is a measured angular distance, often used to find longitude. For example, the Greenwich Hour Angle (GHA) of a star is essentially the star's longitude-like coordinate measured from Greenwich; comparing it to your local meridian angle gives your longitude.
Because the Earth rotates 15 degrees per hour. A meridian angle of 30 degrees corresponds to a time difference of 2 hours. In navigation, it's often expressed in hours, minutes, and seconds of time for practical use.
No, the angle itself is always a positive value. The direction (east or west) is specified separately (e.g., '15 degrees west'). However, in mathematical formulas, west might be treated as positive and east as negative, or vice versa, depending on the convention.
The underlying mathematical principles of satellite positioning are related, but GPS receivers perform these calculations internally using Cartesian coordinates and algorithms. Traditional mariners and celestial navigation enthusiasts still manually calculate meridian angles as a backup skill.
The angular distance, measured east or west from a reference meridian (typically the observer's celestial meridian or the Greenwich meridian), to the position of a celestial body or point.
Meridian angle is usually formal / technical / scientific in register.
Meridian angle: in British English it is pronounced /məˈrɪd.i.ən ˈæŋ.ɡəl/, and in American English it is pronounced /məˈrɪd.i.ən ˈæŋ.ɡəl/. Tap the audio buttons above to hear it.
Phrases
Idioms & Phrases
- “[No established idioms for this technical term]”
Learning
Memory Aids
Mnemonic
Imagine the Earth as a giant orange with lines (meridians) running from the North to South Pole. A 'meridian angle' is how far you have to turn (in degrees) along the orange's skin, east or west, from one specific line to reach the spot right under the Sun or a star.
Conceptual Metaphor
A CLOCK FACE ON THE SKY: The celestial meridian is like the 12 o'clock line. The meridian angle tells you how many hours (or degrees) before or after 12 o'clock a star is positioned.
Practice
Quiz
In which field is the term 'meridian angle' MOST commonly used?