CMRT CMRT Target Tracking & ARPA 1

Question 1

What does ARPA stand for in the context of marine radar systems?

Accepted Answer

Automatic Radar Plotting Aid

Answer

ARPA stands for Automatic Radar Plotting Aid, a system that automatically tracks targets and computes their motion vectors.

Question 2

Which parameter does ARPA calculate to determine collision risk with a tracked target?

Accepted Answer

Closest Point of Approach (CPA)

Answer

ARPA calculates CPA (Closest Point of Approach) and TCPA (Time to CPA) to assess collision risk with each tracked target.

Question 3

What is the minimum number of targets an ARPA system complying with IMO Resolution MSC.192(79) must be capable of tracking simultaneously?

Accepted Answer

100

Answer

IMO Resolution MSC.192(79) requires ARPA systems to track a minimum of 100 targets simultaneously.

Question 4

In ARPA terminology, what is 'target swap'?

Accepted Answer

A tracking error where the system exchanges the identity of two nearby targets

Answer

Target swap occurs when two closely spaced targets pass near each other and the ARPA incorrectly exchanges their tracked identities.

Question 5

What is the purpose of the 'guard zone' feature in an ARPA/radar system?

Accepted Answer

To automatically alarm when a target enters a defined range or sector

Answer

A guard zone triggers an alarm whenever a radar return or tracked target enters the user-defined range ring or sector area.

(CMRT) Certified Marine Radar Technician Practice Test