What is a typical expected AIS range at sea, depending on antenna height?

What is a typical expected AIS range at sea, depending on antenna height?

• A. 10-20 nautical miles
• B. 20-30 nautical miles
• C. 30-40 nautical miles
• D. 40-50 nautical miles

Answer: (B)

The expected AIS (Automatic Identification System) range at sea, which can vary depending on several factors, is generally between 20 to 30 nautical miles. This range is influenced primarily by the height of the antennas used on the vessels. A higher antenna allows for a greater line of sight, thus increasing the effective coverage area for AIS transmissions. AIS operates in the VHF maritime mobile band (typically around 156.025 MHz) and employs Line of Sight propagation characteristics. Therefore, as the height of the antennas increases, the range of AIS communications also increases. While there can be variations due to environmental conditions and the radio horizon, under normal circumstances, 20 to 30 nautical miles is a realistic average expected range when considering standard operational conditions and equipment height on vessels. This understanding is crucial for navigating and ensuring situational awareness at sea, particularly in busy shipping lanes or in conjunction with other navigational aids.

The expected AIS (Automatic Identification System) range at sea, which can vary depending on several factors, is generally between 20 to 30 nautical miles. This range is influenced primarily by the height of the antennas used on the vessels. A higher antenna allows for a greater line of sight, thus increasing the effective coverage area for AIS transmissions.

AIS operates in the VHF maritime mobile band (typically around 156.025 MHz) and employs Line of Sight propagation characteristics. Therefore, as the height of the antennas increases, the range of AIS communications also increases. While there can be variations due to environmental conditions and the radio horizon, under normal circumstances, 20 to 30 nautical miles is a realistic average expected range when considering standard operational conditions and equipment height on vessels.

This understanding is crucial for navigating and ensuring situational awareness at sea, particularly in busy shipping lanes or in conjunction with other navigational aids.