Long Term Statistics Calculation

The Long Term Statistics Calculation defines how environmental conditions (wave, wind, and current) are extracted from Long Term Statistics and converted to conditions that can be used in SIMA analyses.

  • Long Term Statistics: Select the long-term statistics data source

  • Input Reference System: Defines the input reference system of the data. If the data is defined in the Metocean system the corresponding SIMA coordinate system data is generated

  • Period: Select which period within the long-term statistics to use

  • Apply NORSOK N-006: Apply NORSOK N-006 (a directional factor of 6 corresponding to 12 directions is applied to the return period) (default: true)

1. Wave

  • Method: Select the method for deriving wave extreme values

    • From distribution - Calculate extreme values from the Weibull distribution parameters for significant wave height

    • From contour data - Extract extreme values directly from contour data

  • Statistics: Select which wave statistics dataset within the chosen period to use

  • Omni: Select the omnidirectional wave statistics (shown when Apply NORSOK is enabled)

  • Return Period: Return period for which wave extreme values should be calculated (year). When using "From contour data", available return periods are populated from the contour data

1.1. Directions

Calculate for given directions.

Column Description

Direction

Wave direction (deg)

Use the Populate from statistics action to automatically populate the directions from the selected wave statistics sectors.

2. Wind

  • Method: Select the method for deriving wind extreme values

    • From distribution - Calculate extreme values from the Weibull distribution parameters

    • From extremes - Use extreme values directly from the defined extreme value tables

  • Statistics: Select which wind statistics dataset within the chosen period to use

  • Omni: Select the omnidirectional wind statistics (shown when Apply NORSOK is enabled)

  • Omni Method: Method for deriving omnidirectional wind extreme values (shown when Apply NORSOK is enabled)

  • Return Period: Return period for which wind extreme values should be calculated (year)

  • Direction Relative to Wave: Direction of wind relative to wave direction (deg)

2.1. Levels

Column Description

Level

Height above sea level (m)

Use the Populate from statistics action to automatically populate the levels from the selected wind statistics.

3. Current

  • Method: Select the method for deriving current extreme values

    • From distribution - Calculate extreme values from the Weibull distribution parameters

    • From extremes - Use extreme values directly from the defined extreme value tables

  • Statistics: Select which current statistics dataset within the chosen period to use

  • Omni: Select the omnidirectional current statistics (shown when Apply NORSOK is enabled)

  • Omni Method: Method for deriving omnidirectional current extreme values (shown when Apply NORSOK is enabled)

  • Return Period: Return period for which current extreme values should be calculated (year)

  • Direction Relative to Wind: Direction of current relative to wind direction (deg)

3.1. Levels

Column Description

Level

Depth below sea level (m)

Use the Populate from statistics action to automatically populate the levels from the selected current statistics.

4. Output Reference System

When using the Metocean input reference system, results are transformed to the SIMA coordinate system.

  • Relative Compass Angle: Relative angle between analysis x-axis and north direction in anti-clockwise direction. Should match the angle given in the receiving SIMA task location (deg)

5. See Also