VTS Equipment and Technology 2

Question 1

What is the primary advantage of an S-band radar (3 GHz) over X-band radar (9 GHz) in a VTS center?

Accepted Answer

Superior performance in heavy rain and adverse weather

Answer

S-band radar operates at a lower frequency which suffers less attenuation from rain and weather, making it preferable in adverse conditions.

Question 2

In AIS, what does a Class A transponder transmit that a Class B transponder does NOT?

Accepted Answer

Rate of turn (ROT) and navigational status

Answer

Class A transponders transmit rate of turn (ROT) and navigational status fields, which are not included in Class B transmissions.

Question 3

A VTS operator notices a radar target has no associated AIS return. What is the MOST likely explanation?

Accepted Answer

The vessel is not AIS-equipped or its transponder is off

Answer

Radar can detect any vessel with sufficient reflectivity, while AIS requires an active transponder, so a radar-only target typically indicates no AIS equipment or a deactivated transponder.

Question 4

What type of VHF antenna configuration is typically used at VTS stations to achieve omnidirectional coverage of a harbor?

Accepted Answer

Collinear omnidirectional antenna

Answer

Collinear omnidirectional antennas provide 360-degree coverage with gain, making them ideal for VTS harbor communications.

Question 5

In a VTMIS (Vessel Traffic Management Information System), what is the function of sensor fusion?

Accepted Answer

Combining radar and AIS data into a single tracked target

Answer

Sensor fusion correlates radar plots and AIS reports into a single composite track, giving operators a more complete and reliable picture of vessel movements.

(VTS) Vessel Traffic Services Operator Exam Practice Test

(VTS) Vessel Traffic Services Operator Exam Practice Test

VTS Equipment and Technology 2