VTS Equipment and Technology 4

Question 1

What technology is used in a VTS tidal monitoring system to measure water depth in real time?

Accepted Answer

Acoustic Doppler Current Profiler (ADCP) and pressure transducer gauges

Answer

VTS tide gauges typically use acoustic sensors, pressure transducers, or float-based systems, while ADCPs also measure current velocity at multiple depths.

Question 2

A VTS operator observes significant 'blind sectors' on the primary radar display. What is the most common cause?

Accepted Answer

Physical obstructions such as buildings or terrain blocking the antenna beam

Answer

Blind sectors occur when physical structures block portions of the radar beam, creating areas with no radar coverage that must be compensated with overlapping radar coverage or other sensors.

Question 3

Which ITU frequency band is allocated for AIS transmissions?

Accepted Answer

VHF (156–174 MHz) specifically channels 87B and 88B

Answer

AIS operates on VHF maritime channels 87B (161.975 MHz) and 88B (162.025 MHz) using TDMA technology.

Question 4

What is the purpose of a Differential GPS (DGPS) beacon station used in conjunction with VTS operations?

Accepted Answer

To provide enhanced GPS accuracy by broadcasting correction signals to nearby receivers

Answer

DGPS stations broadcast correction signals derived from a fixed reference receiver, reducing GPS position errors to sub-meter accuracy for nearby vessels.

Question 5

In a digital VHF recording system used by VTS, what is the primary reason for time-stamping all recorded communications?

Accepted Answer

To enable accurate reconstruction of the sequence of events during incident investigations

Answer

Time-stamped recordings allow investigators to reconstruct the precise timeline of communications during incidents, collisions, or near-misses.

(VTS) Vessel Traffic Services Operator Exam Practice Test

(VTS) Vessel Traffic Services Operator Exam Practice Test

VTS Equipment and Technology 4