Subelement D: Display & Control Systems - 10 Key Topics – 10 Exam Questions— Topic 36: ARPA - CAS
Question 8-36D3
Element 8 (RADAR)Which of the following would not be considered an input to the computer of a collision avoidance system?
Explanation
A collision avoidance system is designed to predict potential impacts by analyzing the movement of your vessel and others. To do this accurately, it primarily needs to know your vessel's precise location, its direction of travel, and its speed.
* **A) Own ship’s exact position from navigation satellite receiver:** This is a crucial input. Systems like GPS rely on radio signals from satellites to provide the vessel's latitude and longitude, essential for plotting its current location and projecting its future path.
* **B) Own ship’s gyrocompass heading:** Knowing the ship's heading is vital for determining its course over ground or water, allowing the system to project its trajectory accurately.
* **C) Own ship’s speed from Doppler log:** Speed is another critical parameter. A Doppler log can use radio (microwave) or acoustic (sonar) waves to measure the vessel's speed, which is necessary for calculating its rate of movement and predicting future positions.
* **D) Own ship’s wind velocity from an anemometer:** While wind speed and direction are important for general navigation, weather routing, and ship handling, they are not direct inputs for the core kinematic calculations of a collision avoidance system. The system utilizes the ship's actual resulting speed and heading (derived from inputs A, B, and C) to predict collisions, regardless of how those movements are influenced by external factors like wind.
Related Questions
8-36D1 The ship’s speed indication on the ARPA display can be set manually, but does not change with changes in the vessel’s speed. What other indication would point to a related equipment failure?8-36D2 What does the term ARPA/CAS refer to?8-36D4 Which answer best describes a line on the display which indicates a target’s position. The speed is shown by the length of the line and the course by the direction of the line.8-36D5 What is the purpose or function of the “Trial Mode” used in most ARPA equipment?8-36D6 The ARPA term CPA refers to: