Tidal Constituent Amplitude Combiner

Synthesize supplied harmonic tidal constituents with explicit phase/time datum; not a fixed six-hour cosine interpolation or prediction of surge residuals.

Description

A tide can be represented as a sum of harmonic constituents.

A tide can be represented as a sum of harmonic constituents. Amplitudes, phases and periods need one consistent time and level datum.

Synthesize supplied harmonic tidal constituents with explicit phase/time datum; not a fixed six-hour cosine interpolation or prediction of surge residuals.

When to use Tidal Constituent Amplitude Combiner

Use this tool to synthesize supplied harmonic tidal constituents with explicit phase/time datum; not a fixed six-hour cosine interpolation or prediction of surge residuals.

Gather the water, wave, current or profile observations and any supplied calibration constants. Confirm units and the stated coordinate and pressure conventions.

How to use Tidal Constituent Amplitude Combiner and understand its results

Gather the water, wave, current or profile observations and any supplied calibration constants. Confirm units and the stated coordinate and pressure conventions.
Enter timesHours, constituentAmplitudesM, constituentPeriodsHours, constituentPhasesDegrees, datumOffsetM using the field table and calculation rules, then run the tool.
Read predictedHeightsM. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
timesHours	Times hours	list of number	Required
constituentAmplitudesM	Constituent amplitudes m	list of number	Required
constituentPeriodsHours	Constituent periods hours	list of number	Required
constituentPhasesDegrees	Constituent phases degrees	list of number	Required
datumOffsetM	Datum offset m	number	Required

Align nonnegative amplitudes, positive periods and signed phases in degrees. Evaluate a nonempty hour list, retaining caller order and bounded total constituent evaluations.^[1]

Paired lists must be nonempty and have equal lengths.

height(t) = datum + Σ amplitude × cos(2πt/period + phase)

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
predictedHeightsM	Predicted heights m	list of number

json

{
  "input": {
    "timesHours": [
      0,
      1,
      2
    ],
    "constituentAmplitudesM": [
      1,
      0.5
    ],
    "constituentPeriodsHours": [
      4,
      2
    ],
    "constituentPhasesDegrees": [
      0,
      0
    ],
    "datumOffsetM": 1
  },
  "output": {
    "predictedHeightsM": [
      2.5,
      0.5,
      0.5
    ]
  }
}

Limitations and assumptions

No constituent estimation or nonastronomical surge prediction is performed.

Numbers and computed results must be finite; overflow produces an error. Numeric lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use Surge Residual Minus Astronomical: Subtract a bracketed interpolated astronomical-tide series from observed levels on the same datum; residual includes all non-tidal errors/processes, not purely meteorological surge. For a complementary task, use Tidal Range Power Density Estimate: Screen ideal single-basin range energy and cycle-averaged electrical output with supplied efficiency; not a tidal-stream kinetic power calculation or plant yield guarantee.

References

Tidal Constituent Amplitude Combiner — tool.io

Similar or alternative tools

Surge Residual Minus Astronomical
Subtract a bracketed interpolated astronomical-tide series from observed levels on the same datum; residual includes all non-tidal errors/processes, not purely meteorological surge.
Tidal Range Power Density Estimate
Screen ideal single-basin range energy and cycle-averaged electrical output with supplied efficiency; not a tidal-stream kinetic power calculation or plant yield guarantee.