Nav maths Theory Flashcards
What are the names for the poles of earth? (Earth Poles Question)
Terrestrail/Geographical
Where are the two poles on Earth? (Earth Poles Question)
North And South Pole
What meets what at the poles? (Earth poles Question)
The axis of spin meets the Earth’s Surface
What does a Great Circle pass through?
The Centre of Earth
What is the only True Great Circle? And why?
The equator due to the Earth’s oblateness and equatorial bulge
What does a GC represent?
The shortest distance between points on the surface
How is a small circle represented?
It does not pass the earth’s centre
Apart from the equator, what is a small circle?
Parallels of latitude
What is the definition of The equator?
A line drawn equally between the poles
Divides the earth into north and southern hemispheres
Combines the parallel of latitude 0°
What is the definition of a meridian
An arc (Semi GC) between two points on the earth’s surface that has the same longitude
What are the parallels of latitude?
They are the equator and small circles that are parallel to the plane of the equator
What is D’Lat?
An arc of an meridian measured North or South from one parallel of latitiude to another.
What is D’Long?
A measurement from one meridian to another. It is labelled either east or west
What are Rhumblines?
Lines on the earth that maintains the same heading where the course cuts all the meridians at the same angle. They are shown as a straight line on a mercator chart
What are meridional Parts?
the number of longitude units contained in a meridian between the parallel of that latitude and the equator
What is a nautical Mile?
It is derived from the circumference of the earth subtended by the angle of 1’ at the centre of the curvature of the earth
What is a vertex?
The highest point of a GC (the position on a GC track that is closest to the pole and the max latitude the ship will experience)
