Fundamentals Of Navigation Flashcards
Great circle:
Largest circle that can be drawn on the surface of a sphere.
Radio waves follow the path of a great circle!
Shortest distance between two points on a sphere is a great circle
Small circle
Small circles are all imaginary circles that don’t cut the earth into two equal portions.
All parallels of latitude a small circles except for equator, which is a great circle
Rhumb lines
A line that crosses all meridians at the same angle.
Generally not the shortest distance between two point s, exceptions are when a run line is a great circle.
Meridians of longitude are both great circle and RAM line.
Equator is a great circle and a rhumb line.
What is both a rhumb line and a great circle?
Equator, intercepts Meridians at 90°.
All meridianss of longitude. Cross all meridians at same angle, 0°.
Corresponding Meridian to prime meridian?
Dateline, 180th Meridian expressed as 180° east or 180° west.
On opposite side of the earth to the prime meridian, prime meridian help to define universal time.
Traveling eastbound across dateline, subtract one day. Traveling westbound across dateline, add one day
Example eastbound Auckland to cook islands, subtract one day
Parallels of latitude
All latitudes are parallel with the equator, hence being named parallels of latitude
Magnetic pole
Magnetic pole is a place where the earth’s magnetic field points vertically downwards.
Currently the magnetic pole is situated in Hudson bay, Canada.
True north
True North is the direction along surface of the earth towards the geographical North pole. Different position to magnetic north, it is the northernmost point where all meridians converge
Magnetic north
The direction that a compass points is magnetic north.
Magnetic north is true north corrected for variation.
Variation is the difference between true north and magnetic north at any one point on the earth
Compass North
Compass North is magnetic north corrected for deviation which is an error introduced by aircraft mechanical and electrical systems. Error is reduced by a compass swing, some error still remains.
Remember deviation east compass least, deviation west compass best.
Grivation
The difference between good North and magnetic north. A combination of conversion to attain true north, and variation to attain magnetic north
Grivation= convergence + variation
Navigation at high latitudes
Mercator charts are not accurate above 70° north or south. Due to charts becoming distorted
Lambert conformal projection charts are commonly used at mid latitudes, where they are far more accurate than mercator charts
Flight management computer
FMC flies great circle track.
Global navigation satellite system GNSS
satellites- 1 !
GPS receiver of times 3D fix of its location which requires a minimum of four satellites in view.
4 barometric aiding, 5 RAIM, 6 with removal of redundant satellite.
GNSS reference system
World Geodetic system 1984 (WGS84)
