Earth Convergency and Conversion Angle Flashcards
What is earth convergency?
The value that a great circle direction changes between 2 points
What is the earth convergency equation?
EC = chlong x sinLat
Where is there 0 convergency?
At the equator
How does convergency change with latitude?
Convergency increases with latitude
What is earth convergency at the poles?
Earth convergency between 2 meridians at either pole is equal to their change in longitude
How does the great circle track travelling east in the northern hemisphere?
Increase in the direction of the great circle track
How does the great circle track travelling west in the northern hemisphere?
Decrease in the direction of the great circle track
How does the great circle track travelling east in the southern hemisphere?
Decrease in the direction of the great circle track
How does the great circle track travelling west in the southern hemisphere?
Increase in the direction of the great circle track
What is the conversion angle?
The angular difference between the great circle track and the rhumb line track
What is the conversion angle formula?
CA = 0.5 x chlong x sinLat
CA = 0.5 x EC
What happens at the midpoint of a track?
The GC and RL track have the same direction
What is the highest latitude?
Point of maximum displacement between the GC track and the RL track
What is the equation for the highest latitude?
X = (CA x total RL distance)/230
X - Distance between RL and GC in nm
230 - Constant
CA - Conversion angle
