Abstract
The sea wave spectra on the ocean surface has to be measured accurately under various synoptic weather conditions. The present paper, rather than similar methods such as by the TUCKER (1952)system, deals with the method by which the ship's vertical acceleration Z and the vertical height ζ from one fixed point upon the ship to the sea level are measured at the same time, without recording the wave profile on the sea-surface, and carrying out the spectral synthesis on the basis of the following spectral synthesis theorem:
and directly determine the wave spectrum Sη(ω) by the computation of each spectrum from those measured values.
Inasmuch as the existing instrumentation is inconvenient in practicing the observing method of new high quality based upon the abovementioned theory, a more convenient and feasible instrumentation model will be proposed, and its benefits and available extetnt of use as well as accuracy will be referred to.
