Lesson 5: Navigation Lesson 5: Navigation Instruments Instruments
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Lesson 5: Navigation InstrumentsLesson 5: Navigation Instruments
AGENDA:– Measurement of Depth– Measurement of Direction– Measurement of Distance– Measurement of Speed
Applicable reading: Hobbs pg. 110-128.
Lesson 5: Navigation InstrumentsLesson 5: Navigation Instruments
Measurement of DepthMeasurement of Depth
Echo Sounder (fathometer) Hand leadline
Lead LineLead Line
Manual method of determining depth
Also allows for a sampling of the bottom type
Measurement of DirectionMeasurement of Direction
Bearing: the horizontal direction of one terrestrial point as measured from another, expressed as an angle from 0 to 360 degrees.
There are three references for bearings:– Relative– Magnetic– True
000T / 270R
090T / 000R
180T / 090R
270T / 180R
Visual Bearings can be measured in:
- Degrees Relative ( # # # 0R )
- Degrees Magnetic ( # # # pstgc OR 0M )
- Degrees True ( # # # 0T)
The navigator must convert any of these types of bearings to True before they can be plotted on the chart.
Measurement of DirectionMeasurement of Direction
Azimuth or Bearing Circle Telescopic Alidade
Bearing Circle/AlidadeBearing Circle/Alidade
Telescopic Alidade
Bearing CircleBearing Circle
Measurement of DistanceMeasurement of Distance
Radar - Distance is obtained by a radio wave that is transmitted into the air and returns as an echo. The time interval between transmission and return can be converted into a physical range.
Used for distance (range) only!!Not normally used for bearings
Measurement of DistanceMeasurement of Distance
STADIMETERUsed to determine precise ranges between ships in formation
Making an Observation with the Making an Observation with the StadimeterStadimeter
Distance is determined by: distance = height of object / tan (angle)
Parallel Ruler
Plotting InstrumentsPlotting Instruments
Parallel Plotter
Plotting InstrumentsPlotting Instruments
Parallel Motion Protractor
Plotting InstrumentsPlotting Instruments
Compass Dividers
Plotting InstrumentsPlotting Instruments
Nautical Slide Rule
Plotting InstrumentsPlotting Instruments
Given two of the following, find the third:– Speed
– Distance
– Time
Operation of Nautical slide RuleOperation of Nautical slide Rule
Measurement of SpeedMeasurement of Speed
Speed over Ground (SOG) = true speed Speed through the water
SPEED OVER GROUND• Direct output of many
electronic navigation systems (GPS, Loran)
SPEED THROUGH WATER• Impeller Log• Pitotmeter Log• Doppler Speed Log• Shaft RPM
Measurement of SpeedMeasurement of Speed
Impeller Log
Measurement of SpeedMeasurement of Speed
Pitometer (Pit) Log
Measurement of SpeedMeasurement of Speed
Doppler Speed Log
The Distance in yards that a ship travels in 3 minutes (D) is equal to the Ship’s Speed (Spd) in knots multiplied by 100.
D = Spd x 100
3 Minute Rule3 Minute Rule
The Distance in nautical miles that a ship travels in 6 minutes (D) is equal to the Ship’s Speed (Spd) in knots divided by 10.
6 Minute Rule6 Minute Rule
D = SPD
10
REVIEWREVIEW
What does a fathometer measure? What does D=Speed x 100 tell you?
QUESTIONS??QUESTIONS??
Related Documents
