手法を比較

	地衡流速	音響ドップラー流速プロファイラー	調和解析 (Tidal Harmonic Analysis)
分野	海洋学	海洋学	海洋学
系統	Process / pipeline	Process / pipeline	Process / pipeline
提唱年	1942	1983	1867
提唱者	Harald Sverdrup	RD Instruments	William Thomson
種類	theoretical-method	instrumental	fourier-analysis
原典	Sverdrup, H. U., Johnson, M. W., & Fleming, R. H. (1942). The Oceans: Their Physics, Chemistry, and General Biology. Prentice-Hall.	RD Instruments. (1996). Acoustic Doppler Current Profiler Principles of Operation. A Practical Primer. RD Instruments Technical Note.	Godin, G. (1972). The Analysis of Tides. University of Toronto Press.
別名	Geostrophic Current, Thermal Wind Equation	ADCP	Tidal Constituents, Harmonic Tidal Prediction
関連	3	3	3
概要	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.	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.	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.