Earth, charts, time, magnetic compass and directions Flashcards
perihelion
where earth is closest to the sun
aphelion
where earth is farthest from the sun
Solar days in a year
365.24
Axial tilt
Earth tilt compared to the sun 23.5 degrees
Longitude
Lines connecting the polars
Latitude
Lines horizontally to the earth
Summer solstice
In the northern hemiphsphere, where the earths tilt towards the sun it at maximum extent
meridian of longitude
Semicircle joining the poles
Prime Meridian
Zero longitude, passes on Greenwich time (London)
Anti-meridian
The opposite side of prime merdiain, 180E/W
parallel of latitude
a line parallel to the equator
Meridian examples
30E, 30W
Parallels examples
30N 30S
True north parallel
90N
True south parallel
90S
A great circle
A line that passes through the center of earth
Examples of great circles
All meridians, the equator, and path followed by radio waves
Great circle two important properties
- The shortest distance between any two points.
- Only one great circle can be drawn between two points, unless they are antipodal or on opposite sides of the earth
small circle
A circle that does not pass on earth center.
Examples of small circles
All parallels except for the equator
Rhumb line
A line that maintains a constant angle at each meridian crossed
Why rhumb line is important compared to great circles
The bearing of the track in a great circle will change continously in flight (passing merdiains at different angles). Rhumb line avoids that.
1 minute of latitude equals to?
1nm
60 minutes of latitude equals to
60nm
1 degree of latitude equals to
60nm
Latitude minutes:
1. מאונך
2. מאוזן
when looking at an area chart
מאונך
Flying from north to south on a meridian, what will change? latitude or longitude? IMPORTANT
Latitude
An aircraft flying from 05 30’S to 32 30’N. How much is the distance in NM
38.
From SOUTH to equator: 5 degrees and 30 minutes
From equator to NOTH: 32 degrees and 30 minutes
IMPORTANT