Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.
CHAPTER 1
INTRODUCTION TO NAVIGATION
Navigation enables mariners to:
• Locate their position
• Travel from one place to another
Terrestrial Sphere or Globe




A sphere on which is depicted a map
of the Earth (terrestrial globe)
North Pole




                         South Pole
The north and south poles are
located at the ends of the axis on
which ...
North Pole



                 Meridians




                               South Pole

Lines running through the poles an...
Equator

The great circle of the Earth that is
equidistant from the North Pole and
South Pole

(Cuts every meridian in hal...
60°                60°


 30°    Northern Hemisphere     30°




0°
             EQUATOR              0°


 30°           ...
Northern     Western
Hemisphere    Hemisphere
 North Pole            North Pole




 South Pole            South Pole

 So...
Hemisphere

Half of a globe
N pole       Greenwich
                              England

               W         E
               LONGITUDE



     ...
Great Circle

Any circle formed by the intersection
of a plane passing through the Earth’s
center, with the Earth’s surface
Prime
                                    Meridian




Parallels
                                     Equator


The equato...
Greenwich meridian
                            (longitude 0°)
                    N




                                  ...
What is the significance of the
great circle in navigation?
What is the significance of the
 great circle in navigation?


The shortest distance between
two points on the Earth lies ...
Arc

Any unbroken part of the
circumference of a circle or
other curved line
Circumference

The distance around a circular area
What is the circumference of the Equator?
360°                         360°



                            Greenwich meridian
                    N
   Center of    ...
360°




   1° = 60 minutes
1 minute = 60 seconds
Measurement along a meridian
or parallel is expressed in terms
of degrees, minutes, and seconds
of arc (the curve of the c...
Greenwich Royal
  Observatory

                       0°


                              0°




The Greenwich meridian is ...
Prime Meridian

The meridian running through
Greenwich, England, from which
longitude east and west is measured
INTERNATIONAL DATE LINE




         NORTH
          POLE




    PRIME MERIDIAN
International
Date Line
           New Date
                        Noon
 Old Date




  Old Day                          ...
Eastern
Hemisphere
             International
               Date Line
                          Equator




             ...
Prime
     Meridian
   0° Longitude




       Meridians

Meridians (longitude lines) between the
prime meridian and 180th...
Longitude

Measurement of position east or west
from the prime meridian
Greenwich




                              Prime
                              Meridian

                      W   E




...
Longitude Lines
Latitude

Measurement of position north or
south of the equator
Latitude




The distance of arc north (N) or
south (S) of the equator, measured
along a meridian
Latitude            Longitude




Equator




                                 Prime
                                merid...
90°                   90°




                       EARTH’S
LATITUDE   LONGITUDE
                         GRID
Remember!
               North
               Pole                  North
                                    Latitude



...
New Orleans, LA
   30N, 90W
Washington, D.C.

38°58'52"N
latitude

77°01'12"W
longitude

Express latitude
and longitude in
degrees, minutes,
and secon...
Washington, D.C.

38°59'N latitude
77°01'W longitude

 This is spoken
 as thirty-eight
 degrees,
 fifty-nine
 minutes nort...
Washington, D.C.

38°58'52"N
latitude

77°01'12"W
longitude

Seconds are used
only if very exact
locations are
required.
Nautical Mile

One minute of arc measured along
the equator, or any other great
circle
6,865 Nautical Miles




    6,888
Nautical Miles




Equatorial Diameter - 6,888 Nautical Miles
Polar Diameter - 6,865 Na...
Comparison of a Statute Mile
           to a Nautical Mile


STATUTE MILE = 5,280 FEET OR 1760 YARDS



    NAUTICAL MILE ...
Dividers




 Distance on a chart is measured along
 the meridian, using a tool called dividers.
Measuring Distance
P
                  30 Nautical
                     Miles
 60°
       Parallel



                    52 Nautical
30°    ...
Remember!

Distances are not
measured on
parallels of latitude,
because one minute
equals one nautical
mile only along the...
1 knot = 1 nautical mile per hour
Origin of the term knot
                          Chip Log




An old sailing day’s log for measuring
the speed of a vessel
True Nautical Direction




Measured from true north (North Pole)
as located on a globe
32-point Compass
Cardinal Points

The four primary directions of the
compass; the north, south, east,
and west points
Cardinal Directions




North, South, East, West:
the four primary directions
of the compass
On the compass rose above, only north
is filled in. Fill in the rest of the points
on the compass, going clockwise, using
...
On the compass rose above, only north
is filled in. Fill in the rest of the points
on the compass, going clockwise, using
...
Express nautical directions in
three digits:
065° (Zero six five degrees)
090° (Zero nine zero degrees)
Heading – Direction the ship is facing
Course – Direction the ship is steered
through the water
MAGNETIC COMPASS     GYROCOMPASS

Magnetic compasses Gyrocompasses
give direction relative reference true
to magnetic nort...
Gyrocompass
Navigational compass containing a
gyroscope, that, when adjusted for
latitude and speed, shows true north
or c...
MAGNETIC    TRUE
 NORTH     NORTH
Magnetic Compass




A compass having a magnetized
needle generally in line with the
magnetic poles of the Earth
NORTH
                     MAGNETIC
                     POLE




         Canada




     United States
Magnetic compasse...
Variation Angle

Difference between magnetic and true
north in degrees
How Variation Affects the Compass
   Magnetic North   North Pole
                                 Variation




Remember, ...
Converting Direction

To convert from magnetic to true,
just add or subtract the variation
at your location to the magneti...
Example of Converting Direction




If your ship was heading 080° magnetic
in a region where the variation was
10° East, w...
Example of Converting Direction




If your ship was heading 080° magnetic
in a region where the variation was
10° East, t...
Example of Converting Direction




If your ship was heading 270° true in a
region where the variation was 10° East,
what ...
Example of Converting Direction




If your ship was heading 270° true in a
region where the variation was 10° East,
the t...
Bearing

The direction of an object from an
observer, measured clockwise in one
of three standard ways:

• True bearing
• ...
TN




                     Light
                     House


                 090°
                TRUE
               B...
True Bearing

Bearing using true north as the
reference
MAGNETIC         TRUE NORTH
      NORTH




                                     Light
                                   ...
Magnetic Bearing

The direction of an object measured
clockwise from magnetic north
TN




                   RELATIVE
                   BEARING
                     030°


                         Light
 ...
Relative Bearing

The direction of an object measured
clockwise from the ship’s head (bow)
When recording a bearing, assume it to
be a true bearing unless followed by the
letters M or R.
030°M means 30° right of m...
Objects seen by lookouts are reported
in terms of relative bearing by degrees.
Relative Bearings




•   Dead ahead, or bow – 000°R
•   Starboard beam – 090°R
•   Dead astern – 180°R
•   Port beam – 27...
To emphasize that it is a true bearing,
the letter T (for example 030°T) follows
the three-digit true bearing, spoken
―030...
TN




                                   RELATIVE
                                   BEARING
                            ...
Nautical Chart

Type of map used to navigate on
water
Nautical Chart

A nautical
chart is a
standardized
drawing
representing
part of the
navigable
waters of the
Earth.
Hydrography




Science of measurement, description,
and mapping of the Earth’s surface
waters, with special reference to ...
Hydrographic information
given on a chart includes:




• Water depths
• Nature of bottom
• Overhead obstructions
• Naviga...
Globe             Chart
Impossible to     Necessary to
work navigation   work navigation
problems or       problems
chart ...
Cartographers
Makers of maps and charts who use
math to work out chart projection
techniques
It is necessary
to convert the
round surface of
the globe to one
that is flat and
two-dimensional
(having only
length and
...
Planar                Conical        Cylindrical
Orthographic        Perspective Conic    Mercator




Chart projections
Chart Projection

Flat surface representative of the
Earth
Mercator Projection
The best-known map or chart projection
Mercator Projection

Earth is projected onto a
cylinder-shaped piece of paper,
wrapped around the globe at the
equator
Geradus Mercator




          Mercator Projection
• Commonly used for navigational charts
• Developed by a Dutch cartogra...
Great Circle
       Track
                           Rhumb Line

            Conformal Projection
A projection on which an...
Rhumb Line

A curve on the surface of a sphere
that cuts all meridians at the same
angle; the path taken by a vessel or
ai...
Scale of Charts

         SCALE 1:7,500,000



• Used to measure distance
• Relationship between actual
  and chart distan...
Small scales
are used to
depict large
areas on a
chart, and
large scales
are used to
depict small
areas.
Measuring distance on a chart




If an inch on the chart represents 50 miles,
what would five inches represent?
Measuring distance on a chart




If an inch on the chart represents 50 miles,
what would five inches represent?
         ...
Remember

• The larger the scale, the smaller the
  area shown on a given chart or map.

• The large-scale charts show are...
Nautical            Sailing




                       Types of Charts
           Harbor
Nautical charts have information for
safe navigation, such as:




• Symbols, figures, and abbreviations
• Depth of water
...
Harbor charts are large-scale charts that
show harbors and their approaches in
detail.
Coastal
charts are
intermediate-
scale charts
used to
navigate a
vessel whose
position may
be determined
by landmarks
and ...
Sounding

The act of measuring the depth of an
area of water
General
ocean sailing
charts are
small-scale
charts
showing the
approaches
to large
areas of the
coast.
INTRODUCTION TO NAVIGATION
       End of Part 1
INTRODUCTION TO NAVIGATION
          Part 2
Depths of
water may
be given in
feet, fathoms,
or meters.
Fathom (of depth)

A unit of length equal to six feet
(1.8 meters); used chiefly in nautical
measurements
Plotting
Plotting




 In order to use the nautical chart for
navigating, you must know something
  about how courses, bearings, an...
Parallel Rulers
Parallel Rulers

A pair of straightedges connected by
two pivoted crosspieces of equal
length so as to be parallel at all ...
Protractor
An instrument having a graduated arc
for plotting or measuring angles
Three-Arm     Parallel Motion
Protractor   Protractor (PMP)
Measuring
Distance on a
Mercator Chart
Fix (position)

Accurate position determined without
use of any previous position, using
visual, electronic, or celestial
...
Line of Position
      (LOP)
A line indicating
a series of possible
positions of a ship
as a result of
observation or
meas...
SPIRE




  RANGE          BEARING

       Lines of Position
CAPE



                     DISTANCE ARC



   TANGENT
Bearing Lines of Position




Lines corresponding to the bearings
are plotted on the chart. They are
labeled with the 4-di...
Visual Range

Two landmarks or navigation aids are
observed in line, one behind the other
Rear
              Marker
              Front
              Marker




Rear Marker            Visual Range
    Front Marker
A circular line of position




       Distance Arc
Radar   Stadimeter


Devices used to
measure distance
to a landmark

                       Sextant
Stadimeter
 Optical distance-measuring device
 that measures angles to determine
   distance to an object using as a
refer...
Stadimeter
Sextant

An astronomical instrument used to
determine latitude and longitude at
sea by measuring angular distances,
especi...
Sextant
Obtain a fix with these combinations
of lines of position:

•   Two or more lines of bearing
•   A distance arc and a line...
TOWER



                     1545


  A fix from two
  crossed bearings
DOUBLE POINT
   LIGHT


                      A fix by a
                      bearing and
                      distance ...
SMITH
                           POINT




HALL REEF LIGHT


    A fix from three   JONES
    intersecting       BLUFF

  ...
LIGHT
                           W


A fix from two
visual ranges
                 LIGHT
                   X




        ...
Visual Fix

Electronic/Celestial Fix

Dead Reckoning Position


Estimated Position


Plotting Symbols
LIGHTHOUSE


                        1300 FIX

1245 FIX




                                   TOWER


                 FA...
Piloting

The determination
of position by
visual means
Piloting




The determination of the course or
position of a ship or airplane by any
of various navigational methods or
d...
Navigation Aids
  Compass

                  Bearing Circle
                                     Fathometer




        Ch...
Echo sounder (Fathometer)

Sonic device used to measure water
depth
Fathometer
Echo Sounder
Sound Ranging



A method for determining the distance
between a point and the position of a
sound source by measuring the...
In piloting, soundings are usually
taken every 5 minutes.
 D=1/2 t x 4,800 feet per second
A fathometer may
establish a fix
when a navigator
has a chart
showing accurate
bottom contours,
but in practice it
usually...
Electronic navigation is
a form of piloting.
Electronic Navigation

              Advantages

• Unaffected by weather
• Determines ship position electronically

      ...
RADAR




RAdio Detection And Ranging
RADAR

Navigation system using reflected
pulses of energy
RADAR
Advantage of radar, as a navigational
aid, is that it does not require external
transmitting stations.
Disadvantage of radar, as a navigational
aid, is that maximum range is currently
limited to slightly more than line-of-sig...
Lighthouse




Use Reliable Radar Targets
Radar System
PIPS




Targets appear on the scope as
bright spots of light called pips.
The most common scope used is a plan
position indicator (PPI), which gives a
bird’s eye view of the radar coverage
area, t...
Advantages of radar as a navigational
aid include:
 • It can be used at night and during
   periods of low visibility.
 • ...
• Very accurate and rapid
• Used to locate and track storms
• Very important for ship safety
Loran




Long Range Navigation
Loran

Long range navigation system using
radio signals
Loran is a system
of radio signals
broadcast by
stations of known
position.
Loran Receiver

A loran fix is determined by a loran
receiver from the intersection of lines
of position obtained from tho...
GPS Satellites




           Satellite Navigation
The newest electronic navigation system
is the Global Positioning Syste...
Global Positioning
  System (GPS)       • Six 10,900-
                       mile-high
                       orbits
     ...
GPS Navigation
GPS is used for a wide variety of land
navigation purposes, including position
and direction-finding in many new cars
and ...
Military applications of GPS navigation
systems include guidance for:
           • Smart bombs
           • Cruise missiles
Differential GPS




Enhancement by to basic GPS: corrections to
positioning information is determined by land-
based rece...
Ship’s Inertial Navigation
         System (SINS)




Provides accurate and continuous
dead reckoning (DR) positions
SINS gives ships an accurate and
continuous dead reckoning position
using three gyroscopes to determine
latitude, vertical...
Submarines use SINS to navigate when
submerged for months even when
traveling under the Arctic ice cap.
Celestial
Sphere




         Celestial Navigation
Branch of navigation in which position is
determined by the aid of heav...
The widespread availability of GPS is
fast making celestial navigation at sea
a vanishing art.
The sextant is used in celestial
navigation to measure the angle
(altitude) between a heavenly body
and the visible horizo...
Sextants
INDEX MIRROR
                                          LENS
HORIZON
                          INDEX ARM       HOOD
MIRROR
...
Dead Reckoning

Calculation of one's position on the
basis of distance run on various
headings since the last precisely
ob...
Visual Fix

Electronic/Celestial Fix

Dead Reckoning Position


Estimated Position


Plotting Symbols
FIX
       DR POSITION
                         DESTINATION




1200
          DEAD RECKONING TRACK
Set and Drift

Set – The direction in which a ship
      is forced by wind and current


Drift – The speed of that force i...
FIX
       DR POSITION
                                DESTINATION




                                          1615

   ...
A fix at 1200 is plotted and labeled.
A line is drawn from the fix on the
ship’s course of 073°. Course is
labeled above the line, and the
speed of 15 knots is ...
To find the 1300 DR position, use
dividers to measure 15 minutes of
latitude on the vertical latitude
scale printed on the...
The spot is labeled ―1300DR.‖
The Captain orders the Officer
of the Deck (OOD) to put ship on
a new course, 117° at 1330.
Using dividers, mark a spot 7½
miles from the 1300 DR position
along the direction the ship is
steaming.
Label position 1330DR, and
draw a new course line in the
direction of 117°.
Plotting a ship’s
           DR track from one
           fix to the next is a
1400 FIX   continuous
           process wh...
DR PLOT
1400 FIX
At sea, the navigator will use celestial or
electronic means to get positive fixes at
least every morning, noon, and eveni...
In piloting waters, the navigator will
normally be on the bridge getting exact
fixes whenever usable navigation aids
come ...
Currently, electronic plotters incorporate
continuous fix updates received from
GPS, then project current ship’s position
...
Q.1. Define navigation.
Q.1. Define navigation.


A.1. The art and science by which
     mariners find their ship's
     position and guide it saf...
Q.2. What is a chart?
Q.2. What is a chart?


A.2. A type of map used to navigate
     on water
Q.3. What are the imaginary lines
     that run through the poles and
     around the Earth?
Q.3. What are the imaginary lines
     that run through the poles and
     around the Earth?


A.3. Meridians or lines of ...
Q.4. What divides the Earth into the
     northern and southern
     hemispheres?
Q.4. What divides the Earth into the
     northern and southern
     hemispheres?


A.4. The Equator
Q.5. What is a Great Circle?
Q.5. What is a Great Circle?


A.5. Any circle drawn around the
     Earth, the plane of which
     divides the Earth into...
Q.6. Are all meridians great circles?
Q.6. Are all meridians great circles?


A.6. Yes
Q.7. What is the name given to the
     meridian on which the Royal
     Observatory at Greenwich,
     England, is locate...
Q.7. What is the name given to the
     meridian on which the Royal
     Observatory at Greenwich,
     England, is locate...
Q.8. Do parallel and latitudinal lines
     run in the same direction?
Q.8. Do parallel and latitudinal lines
     run in the same direction?


A.8. Yes
Q.9. Navigators determine their
     ship's position using what
     coordinate system?
Q.9. Navigators determine their
     ship's position using what
     coordinate system?


A.9. Latitude and Longitude
Q.10. If the latitude of the equator is
      0 degrees, what is the latitude
      of the North Pole?
Q.10. If the latitude of the equator is
      0 degrees, what is the latitude
      of the North Pole?


A.10. 90 degrees ...
Q.11. Latitude and longitude are
      expressed in what units?
Q.11. Latitude and longitude are
      expressed in what units?


A.11. Degrees, minutes, and
      seconds
Q.12. How many degrees are there in
      a circle?
Q.12. How many degrees are there in
      a circle?


A.12. 360
Q.13. Approximately how many
      yards are in a nautical mile?
Q.13. Approximately how many
      yards are in a nautical mile?


A.13. 2000 yds.
Q.14. What are meridians?
Q.14. What are meridians?


A.14. Great Circles which pass
      through the Earth’s poles
Q.15. In navigation what is a ―knot?‖
Q.15. In navigation what is a ―knot?‖


A.15. A seagoing term meaning one
      nautical mile per hour
Q.16. How is direction expressed?
Q.16. How is direction expressed?


A.16. As an angle between 000
      degrees and 359 degrees
Q.17. What are the cardinal points?
Q.17. What are the cardinal points?


A.17. North, East, South, and West
Q.18. Define ―true bearing.‖
Q.18. Define ―true bearing.‖


A.18. The direction of an object
      measured clockwise from true
      north
Q.19. What does chart projection
      entail?
Q.19. What does chart projection
      entail?


A.19. Projecting a three-dimensional
      object on a two-dimensional
  ...
Q.20. What is the best-known map or
      chart projection called?
Q.20. What is the best-known map or
      chart projection called?


A.20. Mercator projection
Q.21. What are the three basic types
      of charts used by the Navy?
Q.21. What are the three basic types
      of charts used by the Navy?


A.21. a. Navigational
      b. Harbor
      c. Ge...
Q.22. What is a cartographer?
Q.22. What is a cartographer?


A.22. One who makes maps and
      charts
Q.23. What is a fix?
Q.23. What is a fix?


A.23. An accurate position
      determined without reference
      to any previous position. The
 ...
Q.24. What is the difference between
      directions measured on a
      gyrocompass and those
      measured on a magnet...
Q.24. What is the difference between
      directions measured on a
      gyrocompass and those
      measured on a magnet...
Q.25. How is distance on a Mercator
      chart measured?
Q.25. How is distance on a Mercator
      chart measured?


A.25. On a flat surface along any
      meridian where one min...
Q.26. If a half-inch on a chart
      represents 10 miles, how many
      inches would represent 100
      miles?
Q.26. If a half-inch on a chart
      represents 10 miles, how many
      inches would represent 100
      miles?


A.26. ...
Q.27. What is the shortest distance
      between two points on a
      globe?
Q.27. What is the shortest distance
      between two points on a
      globe?


A.27. An arc of a great circle
Q.28. How many feet are in one
      fathom?
Q.28. How many feet are in one
      fathom?


A.28. Six feet
Q.29. What is a line of position
      (LOP)?
Q.29. What is a line of position
      (LOP)?


A.29. A line drawn on a chart along
      which a ship must be located,
  ...
Q.30. A ship that is traveling south
      observes another ship on a
      relative bearing of 041 degrees.
      What is...
Q.30. A ship that is traveling south
      observes another ship on a
      relative bearing of 041 degrees.
      What is...
Q.31. A ship that is traveling north
      observes another ship on a
      relative bearing of 041 degrees.
      Where w...
Q.31. A ship that is traveling north
      observes another ship on a
      relative bearing of 041 degrees.
      Where w...
Sphere

A round body whose surface is at all
points equidistant from the center
Meridian

A great circle of the Earth passing
through the poles and any given
point on the Earth's surface
Parallel

Lines of latitude with only the equator
being a great circle
Dividers

A two–pointed compass used for
dividing lines and measuring
Compass Card




A circular card with magnets attached
to its underside, the face divided on its
rim into points of the co...
Magnetic Compass

Directional instrument that points to
the north magnetic pole


          Gyrocompass

Aligned with true...
Distortion

The state of being misrepresented
a false
Development
of a Mercator
Projection
Sounding
LORAN CHART
Global Positioning System (GPS)

 Electronic navigation system using
 satellites
Intro to Navigation
Intro to Navigation
Intro to Navigation
Intro to Navigation
Upcoming SlideShare
Loading in …5
×

of

Intro to Navigation Slide 1 Intro to Navigation Slide 2 Intro to Navigation Slide 3 Intro to Navigation Slide 4 Intro to Navigation Slide 5 Intro to Navigation Slide 6 Intro to Navigation Slide 7 Intro to Navigation Slide 8 Intro to Navigation Slide 9 Intro to Navigation Slide 10 Intro to Navigation Slide 11 Intro to Navigation Slide 12 Intro to Navigation Slide 13 Intro to Navigation Slide 14 Intro to Navigation Slide 15 Intro to Navigation Slide 16 Intro to Navigation Slide 17 Intro to Navigation Slide 18 Intro to Navigation Slide 19 Intro to Navigation Slide 20 Intro to Navigation Slide 21 Intro to Navigation Slide 22 Intro to Navigation Slide 23 Intro to Navigation Slide 24 Intro to Navigation Slide 25 Intro to Navigation Slide 26 Intro to Navigation Slide 27 Intro to Navigation Slide 28 Intro to Navigation Slide 29 Intro to Navigation Slide 30 Intro to Navigation Slide 31 Intro to Navigation Slide 32 Intro to Navigation Slide 33 Intro to Navigation Slide 34 Intro to Navigation Slide 35 Intro to Navigation Slide 36 Intro to Navigation Slide 37 Intro to Navigation Slide 38 Intro to Navigation Slide 39 Intro to Navigation Slide 40 Intro to Navigation Slide 41 Intro to Navigation Slide 42 Intro to Navigation Slide 43 Intro to Navigation Slide 44 Intro to Navigation Slide 45 Intro to Navigation Slide 46 Intro to Navigation Slide 47 Intro to Navigation Slide 48 Intro to Navigation Slide 49 Intro to Navigation Slide 50 Intro to Navigation Slide 51 Intro to Navigation Slide 52 Intro to Navigation Slide 53 Intro to Navigation Slide 54 Intro to Navigation Slide 55 Intro to Navigation Slide 56 Intro to Navigation Slide 57 Intro to Navigation Slide 58 Intro to Navigation Slide 59 Intro to Navigation Slide 60 Intro to Navigation Slide 61 Intro to Navigation Slide 62 Intro to Navigation Slide 63 Intro to Navigation Slide 64 Intro to Navigation Slide 65 Intro to Navigation Slide 66 Intro to Navigation Slide 67 Intro to Navigation Slide 68 Intro to Navigation Slide 69 Intro to Navigation Slide 70 Intro to Navigation Slide 71 Intro to Navigation Slide 72 Intro to Navigation Slide 73 Intro to Navigation Slide 74 Intro to Navigation Slide 75 Intro to Navigation Slide 76 Intro to Navigation Slide 77 Intro to Navigation Slide 78 Intro to Navigation Slide 79 Intro to Navigation Slide 80 Intro to Navigation Slide 81 Intro to Navigation Slide 82 Intro to Navigation Slide 83 Intro to Navigation Slide 84 Intro to Navigation Slide 85 Intro to Navigation Slide 86 Intro to Navigation Slide 87 Intro to Navigation Slide 88 Intro to Navigation Slide 89 Intro to Navigation Slide 90 Intro to Navigation Slide 91 Intro to Navigation Slide 92 Intro to Navigation Slide 93 Intro to Navigation Slide 94 Intro to Navigation Slide 95 Intro to Navigation Slide 96 Intro to Navigation Slide 97 Intro to Navigation Slide 98 Intro to Navigation Slide 99 Intro to Navigation Slide 100 Intro to Navigation Slide 101 Intro to Navigation Slide 102 Intro to Navigation Slide 103 Intro to Navigation Slide 104 Intro to Navigation Slide 105 Intro to Navigation Slide 106 Intro to Navigation Slide 107 Intro to Navigation Slide 108 Intro to Navigation Slide 109 Intro to Navigation Slide 110 Intro to Navigation Slide 111 Intro to Navigation Slide 112 Intro to Navigation Slide 113 Intro to Navigation Slide 114 Intro to Navigation Slide 115 Intro to Navigation Slide 116 Intro to Navigation Slide 117 Intro to Navigation Slide 118 Intro to Navigation Slide 119 Intro to Navigation Slide 120 Intro to Navigation Slide 121 Intro to Navigation Slide 122 Intro to Navigation Slide 123 Intro to Navigation Slide 124 Intro to Navigation Slide 125 Intro to Navigation Slide 126 Intro to Navigation Slide 127 Intro to Navigation Slide 128 Intro to Navigation Slide 129 Intro to Navigation Slide 130 Intro to Navigation Slide 131 Intro to Navigation Slide 132 Intro to Navigation Slide 133 Intro to Navigation Slide 134 Intro to Navigation Slide 135 Intro to Navigation Slide 136 Intro to Navigation Slide 137 Intro to Navigation Slide 138 Intro to Navigation Slide 139 Intro to Navigation Slide 140 Intro to Navigation Slide 141 Intro to Navigation Slide 142 Intro to Navigation Slide 143 Intro to Navigation Slide 144 Intro to Navigation Slide 145 Intro to Navigation Slide 146 Intro to Navigation Slide 147 Intro to Navigation Slide 148 Intro to Navigation Slide 149 Intro to Navigation Slide 150 Intro to Navigation Slide 151 Intro to Navigation Slide 152 Intro to Navigation Slide 153 Intro to Navigation Slide 154 Intro to Navigation Slide 155 Intro to Navigation Slide 156 Intro to Navigation Slide 157 Intro to Navigation Slide 158 Intro to Navigation Slide 159 Intro to Navigation Slide 160 Intro to Navigation Slide 161 Intro to Navigation Slide 162 Intro to Navigation Slide 163 Intro to Navigation Slide 164 Intro to Navigation Slide 165 Intro to Navigation Slide 166 Intro to Navigation Slide 167 Intro to Navigation Slide 168 Intro to Navigation Slide 169 Intro to Navigation Slide 170 Intro to Navigation Slide 171 Intro to Navigation Slide 172 Intro to Navigation Slide 173 Intro to Navigation Slide 174 Intro to Navigation Slide 175 Intro to Navigation Slide 176 Intro to Navigation Slide 177 Intro to Navigation Slide 178 Intro to Navigation Slide 179 Intro to Navigation Slide 180 Intro to Navigation Slide 181 Intro to Navigation Slide 182 Intro to Navigation Slide 183 Intro to Navigation Slide 184 Intro to Navigation Slide 185 Intro to Navigation Slide 186 Intro to Navigation Slide 187 Intro to Navigation Slide 188 Intro to Navigation Slide 189 Intro to Navigation Slide 190 Intro to Navigation Slide 191 Intro to Navigation Slide 192 Intro to Navigation Slide 193 Intro to Navigation Slide 194 Intro to Navigation Slide 195 Intro to Navigation Slide 196 Intro to Navigation Slide 197 Intro to Navigation Slide 198 Intro to Navigation Slide 199 Intro to Navigation Slide 200 Intro to Navigation Slide 201 Intro to Navigation Slide 202 Intro to Navigation Slide 203 Intro to Navigation Slide 204 Intro to Navigation Slide 205 Intro to Navigation Slide 206 Intro to Navigation Slide 207 Intro to Navigation Slide 208 Intro to Navigation Slide 209 Intro to Navigation Slide 210 Intro to Navigation Slide 211 Intro to Navigation Slide 212 Intro to Navigation Slide 213 Intro to Navigation Slide 214 Intro to Navigation Slide 215 Intro to Navigation Slide 216 Intro to Navigation Slide 217 Intro to Navigation Slide 218 Intro to Navigation Slide 219 Intro to Navigation Slide 220 Intro to Navigation Slide 221 Intro to Navigation Slide 222 Intro to Navigation Slide 223 Intro to Navigation Slide 224 Intro to Navigation Slide 225 Intro to Navigation Slide 226 Intro to Navigation Slide 227 Intro to Navigation Slide 228 Intro to Navigation Slide 229 Intro to Navigation Slide 230 Intro to Navigation Slide 231 Intro to Navigation Slide 232 Intro to Navigation Slide 233 Intro to Navigation Slide 234 Intro to Navigation Slide 235 Intro to Navigation Slide 236 Intro to Navigation Slide 237 Intro to Navigation Slide 238 Intro to Navigation Slide 239 Intro to Navigation Slide 240 Intro to Navigation Slide 241 Intro to Navigation Slide 242 Intro to Navigation Slide 243 Intro to Navigation Slide 244 Intro to Navigation Slide 245 Intro to Navigation Slide 246 Intro to Navigation Slide 247 Intro to Navigation Slide 248 Intro to Navigation Slide 249 Intro to Navigation Slide 250 Intro to Navigation Slide 251 Intro to Navigation Slide 252 Intro to Navigation Slide 253 Intro to Navigation Slide 254 Intro to Navigation Slide 255 Intro to Navigation Slide 256 Intro to Navigation Slide 257 Intro to Navigation Slide 258 Intro to Navigation Slide 259 Intro to Navigation Slide 260 Intro to Navigation Slide 261 Intro to Navigation Slide 262 Intro to Navigation Slide 263 Intro to Navigation Slide 264 Intro to Navigation Slide 265 Intro to Navigation Slide 266 Intro to Navigation Slide 267 Intro to Navigation Slide 268 Intro to Navigation Slide 269
Upcoming SlideShare
Celestial navigation 2014 (pdf)
Next
Download to read offline and view in fullscreen.

39 Likes

Share

Download to read offline

Intro to Navigation

Download to read offline

Related Books

Free with a 30 day trial from Scribd

See all

Related Audiobooks

Free with a 30 day trial from Scribd

See all

Intro to Navigation

  1. 1. CHAPTER 1 INTRODUCTION TO NAVIGATION
  2. 2. Navigation enables mariners to: • Locate their position • Travel from one place to another
  3. 3. Terrestrial Sphere or Globe A sphere on which is depicted a map of the Earth (terrestrial globe)
  4. 4. North Pole South Pole The north and south poles are located at the ends of the axis on which Earth rotates.
  5. 5. North Pole Meridians South Pole Lines running through the poles and around the Earth are called meridians.
  6. 6. Equator The great circle of the Earth that is equidistant from the North Pole and South Pole (Cuts every meridian in half)
  7. 7. 60° 60° 30° Northern Hemisphere 30° 0° EQUATOR 0° 30° 30° Southern Hemisphere 60° 60°
  8. 8. Northern Western Hemisphere Hemisphere North Pole North Pole South Pole South Pole Southern Eastern Hemisphere Hemisphere
  9. 9. Hemisphere Half of a globe
  10. 10. N pole Greenwich England W E LONGITUDE EQUATOR S pole Meridians and the equator are called great circles because they divide the globe into two halves.
  11. 11. Great Circle Any circle formed by the intersection of a plane passing through the Earth’s center, with the Earth’s surface
  12. 12. Prime Meridian Parallels Equator The equator is the only great circle going around the globe from east to west. The other lines are called parallels, since they go around the globe parallel to, and north and south of the equator.
  13. 13. Greenwich meridian (longitude 0°) N Equator (latitude 0°) One example of a great circle S A great circle is any circle whose plane passes through the Earth’s center, no matter what direction.
  14. 14. What is the significance of the great circle in navigation?
  15. 15. What is the significance of the great circle in navigation? The shortest distance between two points on the Earth lies along the path of a great circle passing through those two points.
  16. 16. Arc Any unbroken part of the circumference of a circle or other curved line
  17. 17. Circumference The distance around a circular area
  18. 18. What is the circumference of the Equator?
  19. 19. 360° 360° Greenwich meridian N Center of (longitude 0°) The Earth Regardless of the size of the circle, the circumference Equator (latitude 0°) has 360°. One example of a great circle S
  20. 20. 360° 1° = 60 minutes 1 minute = 60 seconds
  21. 21. Measurement along a meridian or parallel is expressed in terms of degrees, minutes, and seconds of arc (the curve of the circle).
  22. 22. Greenwich Royal Observatory 0° 0° The Greenwich meridian is numbered 0, or 0°, and is called the prime meridian.
  23. 23. Prime Meridian The meridian running through Greenwich, England, from which longitude east and west is measured
  24. 24. INTERNATIONAL DATE LINE NORTH POLE PRIME MERIDIAN
  25. 25. International Date Line New Date Noon Old Date Old Day 0° Prime Meridian New Day Midnight 180° International Date Line International Date Line
  26. 26. Eastern Hemisphere International Date Line Equator Pacific Ocean Western Hemisphere
  27. 27. Prime Meridian 0° Longitude Meridians Meridians (longitude lines) between the prime meridian and 180th meridian are numbered 0° to 180° east (E) or west (W).
  28. 28. Longitude Measurement of position east or west from the prime meridian
  29. 29. Greenwich Prime Meridian W E Longitude The distance of arc east (E) or west (W) of the prime meridian, measured along a parallel
  30. 30. Longitude Lines
  31. 31. Latitude Measurement of position north or south of the equator
  32. 32. Latitude The distance of arc north (N) or south (S) of the equator, measured along a meridian
  33. 33. Latitude Longitude Equator Prime meridian Grid system of latitude and longitude lines
  34. 34. 90° 90° EARTH’S LATITUDE LONGITUDE GRID
  35. 35. Remember! North Pole North Latitude South Latitude West East Longitude South Longitude Pole • Longitude is always measured east or west from 0° through 180° • Latitude is always measured north or south from 0° through 90°
  36. 36. New Orleans, LA 30N, 90W
  37. 37. Washington, D.C. 38°58'52"N latitude 77°01'12"W longitude Express latitude and longitude in degrees, minutes, and seconds.
  38. 38. Washington, D.C. 38°59'N latitude 77°01'W longitude This is spoken as thirty-eight degrees, fifty-nine minutes north, seventy-seven degrees, one minute west.
  39. 39. Washington, D.C. 38°58'52"N latitude 77°01'12"W longitude Seconds are used only if very exact locations are required.
  40. 40. Nautical Mile One minute of arc measured along the equator, or any other great circle
  41. 41. 6,865 Nautical Miles 6,888 Nautical Miles Equatorial Diameter - 6,888 Nautical Miles Polar Diameter - 6,865 Nautical Miles
  42. 42. Comparison of a Statute Mile to a Nautical Mile STATUTE MILE = 5,280 FEET OR 1760 YARDS NAUTICAL MILE = 6,076 FEET OR 2,000 YARDS 0 500 1000 1500 2000 YARDS
  43. 43. Dividers Distance on a chart is measured along the meridian, using a tool called dividers.
  44. 44. Measuring Distance
  45. 45. P 30 Nautical Miles 60° Parallel 52 Nautical 30° Miles 60 Nautical Miles 0° Length of a Degree of Longitude at Various Latitudes
  46. 46. Remember! Distances are not measured on parallels of latitude, because one minute equals one nautical mile only along the equator. Dividers
  47. 47. 1 knot = 1 nautical mile per hour
  48. 48. Origin of the term knot Chip Log An old sailing day’s log for measuring the speed of a vessel
  49. 49. True Nautical Direction Measured from true north (North Pole) as located on a globe
  50. 50. 32-point Compass
  51. 51. Cardinal Points The four primary directions of the compass; the north, south, east, and west points
  52. 52. Cardinal Directions North, South, East, West: the four primary directions of the compass
  53. 53. On the compass rose above, only north is filled in. Fill in the rest of the points on the compass, going clockwise, using the standard abbreviations.
  54. 54. On the compass rose above, only north is filled in. Fill in the rest of the points on the compass, going clockwise, using the standard abbreviations.
  55. 55. Express nautical directions in three digits: 065° (Zero six five degrees) 090° (Zero nine zero degrees)
  56. 56. Heading – Direction the ship is facing Course – Direction the ship is steered through the water
  57. 57. MAGNETIC COMPASS GYROCOMPASS Magnetic compasses Gyrocompasses give direction relative reference true to magnetic north. north.
  58. 58. Gyrocompass Navigational compass containing a gyroscope, that, when adjusted for latitude and speed, shows true north or communicates this information to one or more gyro repeaters.
  59. 59. MAGNETIC TRUE NORTH NORTH
  60. 60. Magnetic Compass A compass having a magnetized needle generally in line with the magnetic poles of the Earth
  61. 61. NORTH MAGNETIC POLE Canada United States Magnetic compasses point to the Earth’s northernmost magnetic pole, located in northern Canada.
  62. 62. Variation Angle Difference between magnetic and true north in degrees
  63. 63. How Variation Affects the Compass Magnetic North North Pole Variation Remember, variation changes depending on your position relative to magnetic north.
  64. 64. Converting Direction To convert from magnetic to true, just add or subtract the variation at your location to the magnetic bearing. Remember — Westerly variations are subtracted, and easterly variations are added.
  65. 65. Example of Converting Direction If your ship was heading 080° magnetic in a region where the variation was 10° East, what is the true heading?
  66. 66. Example of Converting Direction If your ship was heading 080° magnetic in a region where the variation was 10° East, the true heading would be 080° + 10°, or 090° true.
  67. 67. Example of Converting Direction If your ship was heading 270° true in a region where the variation was 10° East, what is the magnetic heading?
  68. 68. Example of Converting Direction If your ship was heading 270° true in a region where the variation was 10° East, the true heading would be 270° – 10°, or 260° magnetic heading.
  69. 69. Bearing The direction of an object from an observer, measured clockwise in one of three standard ways: • True bearing • Magnetic bearing • Relative bearing
  70. 70. TN Light House 090° TRUE BEARING True Bearing
  71. 71. True Bearing Bearing using true north as the reference
  72. 72. MAGNETIC TRUE NORTH NORTH Light House Difference between true and magnetic bearing
  73. 73. Magnetic Bearing The direction of an object measured clockwise from magnetic north
  74. 74. TN RELATIVE BEARING 030° Light House Relative Bearing
  75. 75. Relative Bearing The direction of an object measured clockwise from the ship’s head (bow)
  76. 76. When recording a bearing, assume it to be a true bearing unless followed by the letters M or R. 030°M means 30° right of magnetic north 030°R means 30° off the starboard bow
  77. 77. Objects seen by lookouts are reported in terms of relative bearing by degrees.
  78. 78. Relative Bearings • Dead ahead, or bow – 000°R • Starboard beam – 090°R • Dead astern – 180°R • Port beam – 270°R
  79. 79. To emphasize that it is a true bearing, the letter T (for example 030°T) follows the three-digit true bearing, spoken ―030 degrees true.‖
  80. 80. TN RELATIVE BEARING 030° 090° TRUE Light BEARING House True Bearing = Relative Bearing + True Heading (Subtract 360° if sum is greater than 360°)
  81. 81. Nautical Chart Type of map used to navigate on water
  82. 82. Nautical Chart A nautical chart is a standardized drawing representing part of the navigable waters of the Earth.
  83. 83. Hydrography Science of measurement, description, and mapping of the Earth’s surface waters, with special reference to their use for navigation
  84. 84. Hydrographic information given on a chart includes: • Water depths • Nature of bottom • Overhead obstructions • Navigation aids; buoys, lights, and anchorages
  85. 85. Globe Chart Impossible to Necessary to work navigation work navigation problems or problems chart courses
  86. 86. Cartographers Makers of maps and charts who use math to work out chart projection techniques
  87. 87. It is necessary to convert the round surface of the globe to one that is flat and two-dimensional (having only length and width)—to a flat piece of paper on which a chart is drawn.
  88. 88. Planar Conical Cylindrical Orthographic Perspective Conic Mercator Chart projections
  89. 89. Chart Projection Flat surface representative of the Earth
  90. 90. Mercator Projection The best-known map or chart projection
  91. 91. Mercator Projection Earth is projected onto a cylinder-shaped piece of paper, wrapped around the globe at the equator
  92. 92. Geradus Mercator Mercator Projection • Commonly used for navigational charts • Developed by a Dutch cartographer, Geradus Mercator, in the 1500s • Most useful projection for navigation
  93. 93. Great Circle Track Rhumb Line Conformal Projection A projection on which any rhumb line is shown as a straight line, used chiefly in navigation, though the scale varies with latitude and aerial size and the shape of large areas are greatly distorted
  94. 94. Rhumb Line A curve on the surface of a sphere that cuts all meridians at the same angle; the path taken by a vessel or aircraft that maintains a constant compass direction
  95. 95. Scale of Charts SCALE 1:7,500,000 • Used to measure distance • Relationship between actual and chart distance • Printed near the legend as a ratio, such as 1:7,500,000
  96. 96. Small scales are used to depict large areas on a chart, and large scales are used to depict small areas.
  97. 97. Measuring distance on a chart If an inch on the chart represents 50 miles, what would five inches represent?
  98. 98. Measuring distance on a chart If an inch on the chart represents 50 miles, what would five inches represent? 250 Miles
  99. 99. Remember • The larger the scale, the smaller the area shown on a given chart or map. • The large-scale charts show areas in great detail. • Features appearing on a large-scale chart may not show up at all on a small-scale chart of the same area.
  100. 100. Nautical Sailing Types of Charts Harbor
  101. 101. Nautical charts have information for safe navigation, such as: • Symbols, figures, and abbreviations • Depth of water • Type of bottom • Navigational aids
  102. 102. Harbor charts are large-scale charts that show harbors and their approaches in detail.
  103. 103. Coastal charts are intermediate- scale charts used to navigate a vessel whose position may be determined by landmarks and lights, buoys, or soundings offshore.
  104. 104. Sounding The act of measuring the depth of an area of water
  105. 105. General ocean sailing charts are small-scale charts showing the approaches to large areas of the coast.
  106. 106. INTRODUCTION TO NAVIGATION End of Part 1
  107. 107. INTRODUCTION TO NAVIGATION Part 2
  108. 108. Depths of water may be given in feet, fathoms, or meters.
  109. 109. Fathom (of depth) A unit of length equal to six feet (1.8 meters); used chiefly in nautical measurements
  110. 110. Plotting
  111. 111. Plotting In order to use the nautical chart for navigating, you must know something about how courses, bearings, and lines of position are plotted on it.
  112. 112. Parallel Rulers
  113. 113. Parallel Rulers A pair of straightedges connected by two pivoted crosspieces of equal length so as to be parallel at all times; used for various navigational purposes, especially for transferring the bearing of a plotted course to a compass rose
  114. 114. Protractor An instrument having a graduated arc for plotting or measuring angles
  115. 115. Three-Arm Parallel Motion Protractor Protractor (PMP)
  116. 116. Measuring Distance on a Mercator Chart
  117. 117. Fix (position) Accurate position determined without use of any previous position, using visual, electronic, or celestial observation
  118. 118. Line of Position (LOP) A line indicating a series of possible positions of a ship as a result of observation or measurement
  119. 119. SPIRE RANGE BEARING Lines of Position CAPE DISTANCE ARC TANGENT
  120. 120. Bearing Lines of Position Lines corresponding to the bearings are plotted on the chart. They are labeled with the 4-digit time of observation above the line.
  121. 121. Visual Range Two landmarks or navigation aids are observed in line, one behind the other
  122. 122. Rear Marker Front Marker Rear Marker Visual Range Front Marker
  123. 123. A circular line of position Distance Arc
  124. 124. Radar Stadimeter Devices used to measure distance to a landmark Sextant
  125. 125. Stadimeter Optical distance-measuring device that measures angles to determine distance to an object using as a reference the distance to an object of known height
  126. 126. Stadimeter
  127. 127. Sextant An astronomical instrument used to determine latitude and longitude at sea by measuring angular distances, especially the altitudes of Sun, Moon, and stars
  128. 128. Sextant
  129. 129. Obtain a fix with these combinations of lines of position: • Two or more lines of bearing • A distance arc and a line of bearing • Two or more distance arcs • A visual range and a distance arc • A visual range and a line of bearing • Two simultaneous visual ranges Most commonly used
  130. 130. TOWER 1545 A fix from two crossed bearings
  131. 131. DOUBLE POINT LIGHT A fix by a bearing and distance from the same object 1314
  132. 132. SMITH POINT HALL REEF LIGHT A fix from three JONES intersecting BLUFF bearings
  133. 133. LIGHT W A fix from two visual ranges LIGHT X LIGHT 2152 W
  134. 134. Visual Fix Electronic/Celestial Fix Dead Reckoning Position Estimated Position Plotting Symbols
  135. 135. LIGHTHOUSE 1300 FIX 1245 FIX TOWER FACTORY Marking Ship’s Fix
  136. 136. Piloting The determination of position by visual means
  137. 137. Piloting The determination of the course or position of a ship or airplane by any of various navigational methods or devices
  138. 138. Navigation Aids Compass Bearing Circle Fathometer Chart Stadimeter Radar Buoy Lighthouse
  139. 139. Echo sounder (Fathometer) Sonic device used to measure water depth
  140. 140. Fathometer
  141. 141. Echo Sounder
  142. 142. Sound Ranging A method for determining the distance between a point and the position of a sound source by measuring the time lapse between the origin of the sound and its arrival at the point SONAR (S0und NAvigation and Ranging)
  143. 143. In piloting, soundings are usually taken every 5 minutes. D=1/2 t x 4,800 feet per second
  144. 144. A fathometer may establish a fix when a navigator has a chart showing accurate bottom contours, but in practice it usually serves as a check.
  145. 145. Electronic navigation is a form of piloting.
  146. 146. Electronic Navigation Advantages • Unaffected by weather • Determines ship position electronically Disadvantages • Equipment malfunction • Insufficient coverage
  147. 147. RADAR RAdio Detection And Ranging
  148. 148. RADAR Navigation system using reflected pulses of energy
  149. 149. RADAR
  150. 150. Advantage of radar, as a navigational aid, is that it does not require external transmitting stations.
  151. 151. Disadvantage of radar, as a navigational aid, is that maximum range is currently limited to slightly more than line-of-sight.
  152. 152. Lighthouse Use Reliable Radar Targets
  153. 153. Radar System
  154. 154. PIPS Targets appear on the scope as bright spots of light called pips.
  155. 155. The most common scope used is a plan position indicator (PPI), which gives a bird’s eye view of the radar coverage area, the transmitting ship in the center.
  156. 156. Advantages of radar as a navigational aid include: • It can be used at night and during periods of low visibility. • A fix can be obtained from a single object.
  157. 157. • Very accurate and rapid • Used to locate and track storms • Very important for ship safety
  158. 158. Loran Long Range Navigation
  159. 159. Loran Long range navigation system using radio signals
  160. 160. Loran is a system of radio signals broadcast by stations of known position.
  161. 161. Loran Receiver A loran fix is determined by a loran receiver from the intersection of lines of position obtained from those shore stations.
  162. 162. GPS Satellites Satellite Navigation The newest electronic navigation system is the Global Positioning System (GPS).
  163. 163. Global Positioning System (GPS) • Six 10,900- mile-high orbits • 24 satellites • Continuous three- dimensional fix capability • Fix accurate to within ±10 meters
  164. 164. GPS Navigation
  165. 165. GPS is used for a wide variety of land navigation purposes, including position and direction-finding in many new cars and golf carts.
  166. 166. Military applications of GPS navigation systems include guidance for: • Smart bombs • Cruise missiles
  167. 167. Differential GPS Enhancement by to basic GPS: corrections to positioning information is determined by land- based receivers and transmitted to users. Capable of accuracy to within + 1 meter.
  168. 168. Ship’s Inertial Navigation System (SINS) Provides accurate and continuous dead reckoning (DR) positions
  169. 169. SINS gives ships an accurate and continuous dead reckoning position using three gyroscopes to determine latitude, vertical, and longitude with great accuracy.
  170. 170. Submarines use SINS to navigate when submerged for months even when traveling under the Arctic ice cap.
  171. 171. Celestial Sphere Celestial Navigation Branch of navigation in which position is determined by the aid of heavenly bodies such as the Sun, Moon, and selected stars and planets
  172. 172. The widespread availability of GPS is fast making celestial navigation at sea a vanishing art.
  173. 173. The sextant is used in celestial navigation to measure the angle (altitude) between a heavenly body and the visible horizon.
  174. 174. Sextants
  175. 175. INDEX MIRROR LENS HORIZON INDEX ARM HOOD MIRROR TELESCOPE VERNIER ARC SCALE SCALE MICROMETER DRUM SCALE SCREW Sextant — Nomenclature Reading the Vernier Scale
  176. 176. Dead Reckoning Calculation of one's position on the basis of distance run on various headings since the last precisely observed position, with as accurate allowance as possible being made for wind, currents, compass errors
  177. 177. Visual Fix Electronic/Celestial Fix Dead Reckoning Position Estimated Position Plotting Symbols
  178. 178. FIX DR POSITION DESTINATION 1200 DEAD RECKONING TRACK
  179. 179. Set and Drift Set – The direction in which a ship is forced by wind and current Drift – The speed of that force in knots
  180. 180. FIX DR POSITION DESTINATION 1615 1600 1200 Effect of Set and Drift
  181. 181. A fix at 1200 is plotted and labeled.
  182. 182. A line is drawn from the fix on the ship’s course of 073°. Course is labeled above the line, and the speed of 15 knots is labeled below the line.
  183. 183. To find the 1300 DR position, use dividers to measure 15 minutes of latitude on the vertical latitude scale printed on the side of the chart.
  184. 184. The spot is labeled ―1300DR.‖
  185. 185. The Captain orders the Officer of the Deck (OOD) to put ship on a new course, 117° at 1330.
  186. 186. Using dividers, mark a spot 7½ miles from the 1300 DR position along the direction the ship is steaming.
  187. 187. Label position 1330DR, and draw a new course line in the direction of 117°.
  188. 188. Plotting a ship’s DR track from one fix to the next is a 1400 FIX continuous process while underway.
  189. 189. DR PLOT 1400 FIX
  190. 190. At sea, the navigator will use celestial or electronic means to get positive fixes at least every morning, noon, and evening.
  191. 191. In piloting waters, the navigator will normally be on the bridge getting exact fixes whenever usable navigation aids come into sight.
  192. 192. Currently, electronic plotters incorporate continuous fix updates received from GPS, then project current ship’s position and the DR track onto an electronic chart projection on a computer screen.
  193. 193. Q.1. Define navigation.
  194. 194. Q.1. Define navigation. A.1. The art and science by which mariners find their ship's position and guide it safely from one point to another
  195. 195. Q.2. What is a chart?
  196. 196. Q.2. What is a chart? A.2. A type of map used to navigate on water
  197. 197. Q.3. What are the imaginary lines that run through the poles and around the Earth?
  198. 198. Q.3. What are the imaginary lines that run through the poles and around the Earth? A.3. Meridians or lines of longitude
  199. 199. Q.4. What divides the Earth into the northern and southern hemispheres?
  200. 200. Q.4. What divides the Earth into the northern and southern hemispheres? A.4. The Equator
  201. 201. Q.5. What is a Great Circle?
  202. 202. Q.5. What is a Great Circle? A.5. Any circle drawn around the Earth, the plane of which divides the Earth into two equal parts
  203. 203. Q.6. Are all meridians great circles?
  204. 204. Q.6. Are all meridians great circles? A.6. Yes
  205. 205. Q.7. What is the name given to the meridian on which the Royal Observatory at Greenwich, England, is located?
  206. 206. Q.7. What is the name given to the meridian on which the Royal Observatory at Greenwich, England, is located? A.7. The Prime Meridian
  207. 207. Q.8. Do parallel and latitudinal lines run in the same direction?
  208. 208. Q.8. Do parallel and latitudinal lines run in the same direction? A.8. Yes
  209. 209. Q.9. Navigators determine their ship's position using what coordinate system?
  210. 210. Q.9. Navigators determine their ship's position using what coordinate system? A.9. Latitude and Longitude
  211. 211. Q.10. If the latitude of the equator is 0 degrees, what is the latitude of the North Pole?
  212. 212. Q.10. If the latitude of the equator is 0 degrees, what is the latitude of the North Pole? A.10. 90 degrees or north
  213. 213. Q.11. Latitude and longitude are expressed in what units?
  214. 214. Q.11. Latitude and longitude are expressed in what units? A.11. Degrees, minutes, and seconds
  215. 215. Q.12. How many degrees are there in a circle?
  216. 216. Q.12. How many degrees are there in a circle? A.12. 360
  217. 217. Q.13. Approximately how many yards are in a nautical mile?
  218. 218. Q.13. Approximately how many yards are in a nautical mile? A.13. 2000 yds.
  219. 219. Q.14. What are meridians?
  220. 220. Q.14. What are meridians? A.14. Great Circles which pass through the Earth’s poles
  221. 221. Q.15. In navigation what is a ―knot?‖
  222. 222. Q.15. In navigation what is a ―knot?‖ A.15. A seagoing term meaning one nautical mile per hour
  223. 223. Q.16. How is direction expressed?
  224. 224. Q.16. How is direction expressed? A.16. As an angle between 000 degrees and 359 degrees
  225. 225. Q.17. What are the cardinal points?
  226. 226. Q.17. What are the cardinal points? A.17. North, East, South, and West
  227. 227. Q.18. Define ―true bearing.‖
  228. 228. Q.18. Define ―true bearing.‖ A.18. The direction of an object measured clockwise from true north
  229. 229. Q.19. What does chart projection entail?
  230. 230. Q.19. What does chart projection entail? A.19. Projecting a three-dimensional object on a two-dimensional plane
  231. 231. Q.20. What is the best-known map or chart projection called?
  232. 232. Q.20. What is the best-known map or chart projection called? A.20. Mercator projection
  233. 233. Q.21. What are the three basic types of charts used by the Navy?
  234. 234. Q.21. What are the three basic types of charts used by the Navy? A.21. a. Navigational b. Harbor c. General ocean sailing charts
  235. 235. Q.22. What is a cartographer?
  236. 236. Q.22. What is a cartographer? A.22. One who makes maps and charts
  237. 237. Q.23. What is a fix?
  238. 238. Q.23. What is a fix? A.23. An accurate position determined without reference to any previous position. The intersection of 2 or more lines of position.
  239. 239. Q.24. What is the difference between directions measured on a gyrocompass and those measured on a magnetic compass?
  240. 240. Q.24. What is the difference between directions measured on a gyrocompass and those measured on a magnetic compass? A.24. Directions measured on a gyrocompass are relative to true north, whereas directions measured on a magnetic compass are relative to magnetic north.
  241. 241. Q.25. How is distance on a Mercator chart measured?
  242. 242. Q.25. How is distance on a Mercator chart measured? A.25. On a flat surface along any meridian where one minute of latitude equals one nautical mile
  243. 243. Q.26. If a half-inch on a chart represents 10 miles, how many inches would represent 100 miles?
  244. 244. Q.26. If a half-inch on a chart represents 10 miles, how many inches would represent 100 miles? A.26. Five inches
  245. 245. Q.27. What is the shortest distance between two points on a globe?
  246. 246. Q.27. What is the shortest distance between two points on a globe? A.27. An arc of a great circle
  247. 247. Q.28. How many feet are in one fathom?
  248. 248. Q.28. How many feet are in one fathom? A.28. Six feet
  249. 249. Q.29. What is a line of position (LOP)?
  250. 250. Q.29. What is a line of position (LOP)? A.29. A line drawn on a chart along which a ship must be located, based on a bearing or distance from an object or landmark
  251. 251. Q.30. A ship that is traveling south observes another ship on a relative bearing of 041 degrees. What is the true bearing to that ship?
  252. 252. Q.30. A ship that is traveling south observes another ship on a relative bearing of 041 degrees. What is the true bearing to that ship? A.30. 221 degrees true (180 degrees + 041 degrees)
  253. 253. Q.31. A ship that is traveling north observes another ship on a relative bearing of 041 degrees. Where would you see that ship in relation to your ship?
  254. 254. Q.31. A ship that is traveling north observes another ship on a relative bearing of 041 degrees. Where would you see that ship in relation to your ship? A.31. Off the starboard bow
  255. 255. Sphere A round body whose surface is at all points equidistant from the center
  256. 256. Meridian A great circle of the Earth passing through the poles and any given point on the Earth's surface
  257. 257. Parallel Lines of latitude with only the equator being a great circle
  258. 258. Dividers A two–pointed compass used for dividing lines and measuring
  259. 259. Compass Card A circular card with magnets attached to its underside, the face divided on its rim into points of the compass, degrees clockwise from north, or both, and floating or suspended from a pivot so as to rotate freely
  260. 260. Magnetic Compass Directional instrument that points to the north magnetic pole Gyrocompass Aligned with true north by means of a spinning gyroscope
  261. 261. Distortion The state of being misrepresented a false
  262. 262. Development of a Mercator Projection
  263. 263. Sounding
  264. 264. LORAN CHART
  265. 265. Global Positioning System (GPS) Electronic navigation system using satellites
  • MostafaGaber27

    Feb. 3, 2021
  • LukeAppearance

    Jul. 30, 2020
  • NharnhaAdwoa

    Jul. 14, 2020
  • XanderWayne

    Apr. 10, 2020
  • AlexMelake

    Feb. 23, 2020
  • GeriJing

    Feb. 11, 2020
  • RUTIK96

    Oct. 14, 2019
  • neeraj312

    Jul. 28, 2019
  • FrankoTom

    Jul. 20, 2019
  • Kiran168909

    Mar. 1, 2019
  • OwusuKofi3

    Feb. 21, 2019
  • BenjaminLarbi2

    Feb. 20, 2019
  • WorlakoAyekple

    Feb. 20, 2019
  • StephanieHopeSamiao

    Feb. 19, 2019
  • romalizaformalejo

    Feb. 17, 2019
  • RetondaNympha

    Feb. 17, 2019
  • darkpeacedarkpeace

    Dec. 8, 2018
  • MarlanUmar

    Aug. 26, 2018
  • matcperera

    May. 31, 2018
  • KomnutPonoy

    May. 29, 2018

Views

Total views

13,115

On Slideshare

0

From embeds

0

Number of embeds

14

Actions

Downloads

953

Shares

0

Comments

0

Likes

39

×