DoodsonHarmonic (file format)

Ocean tides are represented as time variable gravitational potential and is given by a fourier expansion \[ V(\M x,t) = \sum_{f} V_f^c(\M x)\cos(\Theta_f(t)) + V_f^s(\M x)\sin(\Theta_f(t)), \]where $V_f^c(\M x)$ and $V_f^s(\M x)$ are spherical harmonics. The $\Theta_f(t)$ are the arguments of the tide constituents $f$: \[ \Theta_f(t) = \sum_{i=1}^6 n_f^i\beta_i(t), \]where $\beta_i(t)$ are the Doodson's fundamental arguments ($\tau,s,h,p,N',p_s$) and $n_f^i$ are the Doodson multipliers for the term at frequency $f$.

To extract the potential coefficients of $V_f^c$ and $V_f^s$ for each frequency $f$ use DoodsonHarmonics2PotentialCoefficients.

See also PotentialCoefficients2DoodsonHarmonics.