General Navigation Flashcards
1
Q
Rhumb line
A
Line of constant track
Always on Equator side from great circle track
2
Q
Earth radius
A
Equatorial radius (semi-major): 6378 km (3440 nm) Polar radius (semi-minor): 6356 km (3429 nm) Diff: 21.39 km
3
Q
Ratio of Ellipticity
A
Ratio of Ellipticity = (a - b) / a = 1/298 = 0.0033
4
Q
Distance along meridian
A
From equator to pole:
10000 km
90* = 5400’
5400 nm
5
Q
Distance along parallel
A
Departure (nm) = Change of Longitude in minutes x cos( Latitude )
6
Q
Convergency
A
Convergency is change of track along great circle due to converging meridians
Conv = Change of Longitude x sin( mean Latitude )
Zero on equator, max on poles, works for change of Longitude < 30*
7
Q
Conversion angle
A
Angle between great circle and rhumb line
Conversion Angle = 1/2 Convergency