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Flashcards in Great circles (23-05-18) Deck (21)
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1

What is a great circle?

a circle around the earth with radius and centre matching that of the Earth.

2

What is a small circle?

Any circle that is not a great circle.

3

How many great circle options do antipodal points have?

infinite

4

What is a loxoddrome/loxodromic line?

A rhumb line from the equator to a pole, which causes a spiral track.

5

What is a rhumb line?

A line connecting 2 positions that crosses all meridians at the same angle relative to north.

6

When comparing rhumb lines and great circles, which is always closer to the nearest pole?

A great circle.

7

When do great circles and rhumb lines intersect?

At the equator.

8

What is geocentric latitude?

latitude measured at the centre of the earth from the equator.

9

What is geodetic/geographic latitude?

latitude measure at a point off set from the centre of the earth which intersects the earths surface at 90degrees, due to the elliptic profile of the Earth.

10

Where is the maximum difference between geodetic and geocentric latitudes found, and what is the maximum difference?

it is found at 45degN/S and the difference is 11.6’ of arc.

11

At what latitude is the arctic circle found?

66.5degN

12

At what latitude is the Tropic of Cancer found?

23.5degN

13

At what latitude is the equator found?

00degN/S

14

At what latitude is the Tropic of Capricorn found?

23.5degS

15

At what latitude is the Antarctic circle found?

66.5degS

16

What is a change in lat referred to as?

Chlat.

17

Where is the prime meridian found?

000degE/W

18

In terms of longitude, what makes up a great circle?

a meridian and its corresponding antimeridian.

19

What is the change in longitude referred to as?

Chlong

20

What is the intersection between lines of latitude and longitude called?

A graticule

It is always a 90 degrees intersection

21

What 3 conditions are required in order to do basic distance calculations based on positions via longitude/latitude?

1- The positions on different latitudes bu the same longitude

2- the positions are on the equator on different longitudes

3 - the positions are on the same latitude and on meridians that are opposite each other (Polar transit)