手法を比較

	調和解析 (Tidal Harmonic Analysis)	音響ドップラー流速プロファイラー	地衡流速
分野	海洋学	海洋学	海洋学
系統	Process / pipeline	Process / pipeline	Process / pipeline
提唱年	1867	1983	1942
提唱者	William Thomson	RD Instruments	Harald Sverdrup
種類	fourier-analysis	instrumental	theoretical-method
原典	Godin, G. (1972). The Analysis of Tides. University of Toronto Press.	RD Instruments. (1996). Acoustic Doppler Current Profiler Principles of Operation. A Practical Primer. RD Instruments Technical Note.	Sverdrup, H. U., Johnson, M. W., & Fleming, R. H. (1942). The Oceans: Their Physics, Chemistry, and General Biology. Prentice-Hall.
別名	Tidal Constituents, Harmonic Tidal Prediction	ADCP	Geostrophic Current, Thermal Wind Equation
関連	3	3	3
概要	Tidal harmonic analysis is a mathematical method that decomposes observed sea level or current time series into a sum of sinusoidal components with specific frequencies, amplitudes, and phases corresponding to astronomical tidal constituents. Developed by William Thomson (Lord Kelvin) in 1867, harmonic analysis enables prediction of tides and understanding of tidal dynamics in coastal regions.	The Acoustic Doppler Current Profiler (ADCP) is an instrument that uses Doppler-shifted acoustic backscatter to measure water velocity profiles along a vertical profile. Developed by RD Instruments in the 1980s, it has become the standard method for high-resolution current profiling in oceanographic research. ADCPs provide unprecedented spatial and temporal resolution of ocean circulation patterns.	Geostrophic velocity is the current driven by balance between the pressure gradient force and the Coriolis force, derived from the thermal wind equation. In most of the ocean away from the equator and coastal boundaries, geostrophic balance is an excellent approximation to the actual flow. Developed by Harald Sverdrup and colleagues in the 1940s, geostrophic velocity calculation from hydrographic data enables estimation of ocean currents without direct current measurements.