TERNAV (quizzes prelim) Flashcards
What is the purpose of an echo sounder on a ship?
To send sound wave pulses for navigation
Which of the following is NOT a method of radio navigation?
Deduced Reckoning
What is the definition of navigation?
The process of directing the movements of a craft from one point to another safely and at the shortest possible distance.
What is the purpose of a passage plan in navigation?
To guide the vessel’s safe passage by determining the most favorable route
What is the purpose of piloting in navigation?
To determine the position of a vessel relative to geographic points
What is the purpose of RADAR ARPA (AutomaticRadar Plotting Aid)?
To calculate collision avoidance data
What is electronic navigation?
Navigation involving the use of electronics in any way
Which of the following is NOT a purpose of electronic navigation?
Weather forecasting
What is dead reckoning in navigation?
Determining position by advancing a known position for courses and distances
What is the main function of a passage plan?
To gather safety and navigation information for a safe voyage
How is an ellipsoid uniquely defined?
By specifying the semi-major axis and the flattening.
How many primary reference surfaces for the Earth are used in geodetic applications?
(not two)
What is the Mercator projection commonly used for in maritime navigation?
To show rhumb lines as straight lines.
What type of projection is the Lambert conformal projection?
Conic projection
Why is it necessary to project the surface of a sphere onto a developable surface?
-
What is the chart datum?
An approximation of the actual mean height of sea level.
What is the geoid?
An equipotential surface that would coincide with the mean ocean surface of the Earth if the oceans and atmosphere were in equilibrium.
What is the difference between an ellipsoid height and a geoid height?
An ellipsoid height is the distance a given point is above or below the ellipsoid surface, while a geoid height is the distance the geoid surface is above or below the ellipsoid surface.
What is the purpose of the geoid in geodetic applications?
To approximate mean sea level (MSL) heights.
What is the distinguishing feature of the Mercator projection?
Expansion of both meridians and parallels at the same ratio with increased latitude.
