1
BDOC NSS Questions and Correct
Answers
According to the NAVDORM, what is the responsibility
of the CO in terms of navigation? Answer: -The CO is
responsible for the safe navigation of the ship. COs will
use all available means of fixing and establishing the
ship's position.
-The Commanding Officer, with assistance from the
Executive Officer and Navigator, will create a ship
specific Navigation Bill, tailored from the NAVDORM, to
adapt to the ship's equipment configuration
-A presence of a maritime pilot does not relieve a
Commanding Officer of his or her responsibilities
How frequently should the Conning Officer hear a fix
report when in Restricted Waters? Answer: 3 minutes
IDENTIFY the common uses of the Global Positioning
System. Answer: The satellites allow a GPS receiver
to determine the longitude, latitude, and altitude of any
position on Earth
Pretest - Stuvia US
,2
GPS was originally intended for military applications,
but the system is now available for civilian use
STATE the advantages of the Global Positioning
System. Answer: Advantages:
-Provides velocity and an extremely accurate and
instantaneous position in three dimensions
-provides users with a standard time
-provides 24-hour coverage, worldwide, in all types of
weather
-GPS is considered a passive system with an unlimited
number of users
What are the disadvantages of GPS? Answer:
Antenna Masking
Electromagnetic Interference
Jamming
Pretest - Stuvia US
,3
Spoofing
Errors
LIST the three major segments of the Global
Positioning System. Answer: 1. Space
2. Control
3. User
IDENTIFY how a Global Positioning System receiver
determines its correct position using satellites as
reference points. Answer: GPS satellites transmit a
signal that contains information, such as time, and
satellite position:
- Receivers interpret the information via triangulation;
thus calculating the receiver's exact position
- The receiver compares the time a signal was
transmitted by a satellite with the time it was received
- The difference equals the distance to the satellite
Pretest - Stuvia US
, 4
DESCRIBE sources of Global Positioning System errors.
Answer: -User clock bias/satellite clock bias
-User clock bias and satellite clock bias are greatly
reduced through the use of at least four satellites
-Atmospheric interference
What is the difference between Rhumb Line and Great
Circles? Answer: Great Circle: The intersection of a
sphere and a plane through its center
i.e. Longitude lines (Meridians), The Equator
Rhumb Lines: A line that makes the same angle with all
meridians
-Meridians and parallels that maintain consistent true
directions may be considered special Rhumb Lines.
What are the 4 areas of navigation and their
parameters? Answer: -Restricted waters: <2nm from
land, FOM<=2; Max Fix: 3 min.
Pretest - Stuvia US
BDOC NSS Questions and Correct
Answers
According to the NAVDORM, what is the responsibility
of the CO in terms of navigation? Answer: -The CO is
responsible for the safe navigation of the ship. COs will
use all available means of fixing and establishing the
ship's position.
-The Commanding Officer, with assistance from the
Executive Officer and Navigator, will create a ship
specific Navigation Bill, tailored from the NAVDORM, to
adapt to the ship's equipment configuration
-A presence of a maritime pilot does not relieve a
Commanding Officer of his or her responsibilities
How frequently should the Conning Officer hear a fix
report when in Restricted Waters? Answer: 3 minutes
IDENTIFY the common uses of the Global Positioning
System. Answer: The satellites allow a GPS receiver
to determine the longitude, latitude, and altitude of any
position on Earth
Pretest - Stuvia US
,2
GPS was originally intended for military applications,
but the system is now available for civilian use
STATE the advantages of the Global Positioning
System. Answer: Advantages:
-Provides velocity and an extremely accurate and
instantaneous position in three dimensions
-provides users with a standard time
-provides 24-hour coverage, worldwide, in all types of
weather
-GPS is considered a passive system with an unlimited
number of users
What are the disadvantages of GPS? Answer:
Antenna Masking
Electromagnetic Interference
Jamming
Pretest - Stuvia US
,3
Spoofing
Errors
LIST the three major segments of the Global
Positioning System. Answer: 1. Space
2. Control
3. User
IDENTIFY how a Global Positioning System receiver
determines its correct position using satellites as
reference points. Answer: GPS satellites transmit a
signal that contains information, such as time, and
satellite position:
- Receivers interpret the information via triangulation;
thus calculating the receiver's exact position
- The receiver compares the time a signal was
transmitted by a satellite with the time it was received
- The difference equals the distance to the satellite
Pretest - Stuvia US
, 4
DESCRIBE sources of Global Positioning System errors.
Answer: -User clock bias/satellite clock bias
-User clock bias and satellite clock bias are greatly
reduced through the use of at least four satellites
-Atmospheric interference
What is the difference between Rhumb Line and Great
Circles? Answer: Great Circle: The intersection of a
sphere and a plane through its center
i.e. Longitude lines (Meridians), The Equator
Rhumb Lines: A line that makes the same angle with all
meridians
-Meridians and parallels that maintain consistent true
directions may be considered special Rhumb Lines.
What are the 4 areas of navigation and their
parameters? Answer: -Restricted waters: <2nm from
land, FOM<=2; Max Fix: 3 min.
Pretest - Stuvia US
