T_MTOD

1. simplified harmonic method of tidal prediction: prediction of tidal heights by combining a simplified set of harmonic constituents into a single time/height curve.
2. full harmonic method of tidal prediction: prediction of tidal heights by combining a complete set of harmonic constituents into a single time/height curve.
3. time and height difference non-harmonic method: prediction of high and low water times and heights by modification of the high and low water times and heights of a known time/height curve.