ARPA Written Exam – OOD || Errorless Answers 100%.
What controls can be adjusted if known targets are not being detected on radar? correct answers
Gain, suppressions, range scale
What factors contribute to the assessment of risk of collision? correct answers -Relative motion
line (CPA/TCPA)
-Aspect
-Error in calculations
When will a radar contact remain stationary on a relative motion radar display? correct answers
When it is on the same course and speed as your vessel
If a radar contact is dead ahead and the range decreases without a change in bearing, what is the
estimated speed of the contact? correct answers Dead in the Water (DIW)
If a radar contact is directly astern and the range decreases without a change in bearing, what is
the estimated speed of the contact? correct answers 15 knots
How can the closest point of approach (CPA) of a contact on a relative motion radar be
determined? correct answers After marking the contact at least twice over a minute
What is a radar display called when North is always at the top of the screen? correct answers
Stabilized display
What inputs are needed to maintain a North-Up, True Motion display on radar? correct answers
Gyro course, speed log
Besides ARPA information, what should an ARPA user consider? correct answers -Limitations of
the information
, -Rules of the road
-Circumstances and external considerations
In restricted visibility, what should you avoid when altering course for a vessel forward of your
beam? correct answers Avoid altering course to port except in overtaking situations
When two ARPA Equipped Ships Collide, What Is Typically True? correct answers Both vessels
are likely to be found at fault
When Using an ARPA, What Should You Consider to Evaluate Displayed Information? correct
answers Navigational constraints may require a target vessel to change course
What Information Is Least Dependent on ARPA Processing? correct answers EBL/VRM data
What Speed Indicators Should Provide Inputs to ARPA Equipment According to IMO? correct
answers The ship's speed through water
Minimum Number of Targets an IMO Approved ARPA Must Track Simultaneously? correct
answers 20
Lowest Range Scale IMO Requires ARPA Facilities to be Available On? correct answers 3 miles
IMO Standards for ARPA Data Display Visibility? correct answers Should be visible to more
than 1 observer in light conditions
IMO Requirements for Past Positions Displayed by ARPAs? correct answers All ARPAs can
display both true and relative past positions
IMO Requires ARPA to Operate in Relative Motion with Which Display? correct answers Either
north-up, head-up, or course-up display
What controls can be adjusted if known targets are not being detected on radar? correct answers
Gain, suppressions, range scale
What factors contribute to the assessment of risk of collision? correct answers -Relative motion
line (CPA/TCPA)
-Aspect
-Error in calculations
When will a radar contact remain stationary on a relative motion radar display? correct answers
When it is on the same course and speed as your vessel
If a radar contact is dead ahead and the range decreases without a change in bearing, what is the
estimated speed of the contact? correct answers Dead in the Water (DIW)
If a radar contact is directly astern and the range decreases without a change in bearing, what is
the estimated speed of the contact? correct answers 15 knots
How can the closest point of approach (CPA) of a contact on a relative motion radar be
determined? correct answers After marking the contact at least twice over a minute
What is a radar display called when North is always at the top of the screen? correct answers
Stabilized display
What inputs are needed to maintain a North-Up, True Motion display on radar? correct answers
Gyro course, speed log
Besides ARPA information, what should an ARPA user consider? correct answers -Limitations of
the information
, -Rules of the road
-Circumstances and external considerations
In restricted visibility, what should you avoid when altering course for a vessel forward of your
beam? correct answers Avoid altering course to port except in overtaking situations
When two ARPA Equipped Ships Collide, What Is Typically True? correct answers Both vessels
are likely to be found at fault
When Using an ARPA, What Should You Consider to Evaluate Displayed Information? correct
answers Navigational constraints may require a target vessel to change course
What Information Is Least Dependent on ARPA Processing? correct answers EBL/VRM data
What Speed Indicators Should Provide Inputs to ARPA Equipment According to IMO? correct
answers The ship's speed through water
Minimum Number of Targets an IMO Approved ARPA Must Track Simultaneously? correct
answers 20
Lowest Range Scale IMO Requires ARPA Facilities to be Available On? correct answers 3 miles
IMO Standards for ARPA Data Display Visibility? correct answers Should be visible to more
than 1 observer in light conditions
IMO Requirements for Past Positions Displayed by ARPAs? correct answers All ARPAs can
display both true and relative past positions
IMO Requires ARPA to Operate in Relative Motion with Which Display? correct answers Either
north-up, head-up, or course-up display
