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Navigation. 3.01 Foundations of Navigation References: FTGU pages 177-178, 184-190 Transport Canada Study and Reference Guide Glider Pilot Canada Flight Training Manual – Pilot Navigation http://en.wikipedia.org/wiki/Transverse_Mercator_projection#Spherical_transverse_Mercator.
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Navigation 3.01 Foundations of Navigation References: FTGU pages 177-178, 184-190 Transport Canada Study and Reference Guide Glider Pilot Canada Flight Training Manual – Pilot Navigation http://en.wikipedia.org/wiki/Transverse_Mercator_projection#Spherical_transverse_Mercator
3.01 Foundations of Navigation • MTPs: • Longitude and Latitude • Time and Longitude • Charts • Lambert Conformal Conic Projection • Transverse Mercator Projection • Great Circles and Rhumb Lines • Magnetic Navigation • Units of Distance and Speed
Longitude and Latitude • Imaginary lines make up a grid on the surface of the earth. • Parallels of Latitude run east to west (like the equator), and are numbered 0 to 90 degrees North and South from the equator. • Meridians of Longitude run north to south and are numbered 0-180 degrees East and West from the Prime Meridian.
Longitude and Latitude • Latitude is measured in degrees, minutes and seconds and includes “north” or “south”. • The equator is at 0 degrees latitude. • Point A is at 15 degrees north.
Longitude and Latitude • Longitude is measured in degrees, minutes and seconds and includes “east” or “west”. • The Prime Meridian is at 0 degrees longitude. • Point A is at about 22 degrees west.
Longitude and Latitude • Coordinates are given by grouping the latitude and longitude of a point together in that order • Each degree is broken into 60’ (minutes) and each minute is broken into 60” (seconds) • The coordinates for Moose Jaw, Saskatchewan are: 50°23′36″N 105°33′07″W
Confirmation • What is the approximate latitude and longitude of each letter? A.______________________ B._______________________ C. ______________________ D. _______________________ C B D A
Confirmation See if you can find the latitude and longitude for your home town. Google it and report it in the chat box!
Time and Longitude • Because the earth rotates, the sun appears to pass over a fixed point on the earth at a rate that varies throughout the year • If we take an average throughout the year, we can calculate the mean solar day • The mean solar day is divided into 24 equal hours • Each hour, the earth will rotate approximately 15 degrees • It will take the earth 4 minutes to rotate approximately 1 degree • This rate actually appears to vary, so we use a common reference • UTC (coordinated universal time) or Z (“Zulu” time) • Time at the prime meridian • Time zones are expressed in hours behind or ahead of UTC or Z • E.g. PST is UTC -8 and PDT is UTC -7
Charts • What is a chart? • Basic Elements of Map Construction: • Area • Shape • Bearing • Distance • Normally one of the elements is closely preserved, the others become distorted.
Charts • Projections are the mathematical basis upon which maps are constructed • Types of projections: Cylindrical Conic Azimuthal
Lambert Conformal Conic Projection • Parallels of Latitude are curved, and • Meridians of Longitude converge at the pole.
Mercator Projection Parallels of Latitude and Meridians of Longitude are straight lines that form a grid.
Great Circles and Rhumb Lines • A great circle is a line that cuts the earth perfectly in half, and represents the shortest distance between two points • An example of a great circle is the equator • A rhumb line is a line which cuts each meridian it crosses at the same angle • A line which could be made by flying the same heading
Great Circles and Rhumb Lines • Drawing a straight line on different projections will yield different results • Lambert Conformal Conic Projection • Great Circle • Mercator (not Transverse Mercator) • Rhumb Line
Magnetic Navigation • The earth generates a magnetic field which is useful for navigation using a compass • This magnetic field is not perfectly aligned with the axis of rotation • This creates a magnetic north which is in a different geographic location from true north • The angular difference between true north and magnetic north is known as variation • This is expressed in degrees east or west of true north
Magnetic Navigation • Isogonic lines connect areas of equal variation • Agonic lines connect areas of 0 variation
Magnetic Navigation • It is possible to convert a true heading to a magnetic heading or a compass heading using the TVMDC method • More on doing this, and on using a compass, in 3.03
Units of Distance and Speed • 1 Statute Mile (SM) is 5 280 feet • 1 Nautical Mile (NM) is 6 080 feet • 1 Knot is 1 Nautical Mile per Hour • The ratio of 1 NM to 1 SM is 1.15
Confirmation Identify the type of projection. What are its characteristics?
Confirmation Identify the type of projection. What are its characteristics?