Intrinsic Wave Frequency
Wave frequency of a periodic wave in a reference frame that is stationary with respect to the wave. NOTE If there is no current, the reference frame is also stationary with respect to the sea floor. If there is a current, the reference frame moves with the same speed and in the same direction as the current.
Source: ISO 19905-1:202, Petroleum and natural gas industries – Site-specific assessment of mobile offshore units – Part 1: Jack-ups. Global Standards