Which of the following is NOT one of the three types of coordinate systems?

• A. Terrestrial
• B. Celestial
• C. Polar
• D. Horizon

Answer: (C)

The three primary types of coordinate systems used in navigation are terrestrial, celestial, and horizon systems. Each of these systems serves a specific purpose in determining positions and movements either on Earth or in relation to celestial bodies.

The terrestrial coordinate system relates to positions on the Earth's surface, typically using latitude and longitude to define locations. The celestial coordinate system, on the other hand, is used for mapping positions in the sky based on the celestial sphere, with common reference points including right ascension and declination. The horizon system takes into account the observer's local horizon to provide a perspective from which objects in the sky are located in relation to that observer's viewpoint.

The polar coordinate system, while it is a valid mathematical system used in various applications such as mathematics and physics, does not specifically fall under the common coordinate systems used in classic navigation or in the context of the three mentioned systems. Therefore, it is correct to identify the polar coordinate system as not being one of the three types of coordinate systems in navigation.