In a light pattern where the total duration of light is longer than the total duration of darkness, which term describes it?

In a light pattern where the total duration of light is longer than the total duration of darkness, which term describes it?

• A. Isophase
• B. Fixed
• C. Flashing
• D. Occulting

Answer: (D)

Patterns of navigational lights are described by how long the light stays on versus how long it stays off in each cycle. When the light is on longer than it is off, the cycle is occulting. This means you’ll see a bright period that lasts longer, with only brief dips into darkness before it comes back on. For comparison, an equal on/off duration defines an isophase pattern, where the light and darkness are matched in time. A fixed light has no dark interval at all, remaining continuously on. A flashing pattern features very brief light pulses with longer periods of darkness between them. So, a light pattern where the total duration of light exceeds the total duration of darkness is described as occulting.

Patterns of navigational lights are described by how long the light stays on versus how long it stays off in each cycle. When the light is on longer than it is off, the cycle is occulting. This means you’ll see a bright period that lasts longer, with only brief dips into darkness before it comes back on.

For comparison, an equal on/off duration defines an isophase pattern, where the light and darkness are matched in time. A fixed light has no dark interval at all, remaining continuously on. A flashing pattern features very brief light pulses with longer periods of darkness between them.

So, a light pattern where the total duration of light exceeds the total duration of darkness is described as occulting.