Scatter data
Scatter diagrams are often based on the hindcast data. They can be prepared directly from the hindcast data or be based on statistical longterm term distributions fitted to the hindcast data.
There are two types of scatter data in the Metocean Task

Omnidirectional Scatter Data

Contains compounded occurrences for all directions


Direction Dependent Scatter Data

Separates the occurences into wave sectors to enable directional spreading.

1. Scatter data editor
The scatter data has three sections

Wave

The wave data is the main section, with wave occurrences collected in Hs/Tp bins.


Wind

Split into several levels, giving possibility to define wind speed and direction for several heights.

The diagram size is governed by the wave diagram size, to ensure the same bins are defined for all data.


Current

Split into several levels, giving possibility to define current speed and direction for several depths.

The diagram size is governed by the wave diagram size, to ensure the same bins are defined for all data.

3. How to create new scatter data

3.1. Generate a metocean task
Right click and choose new




3.2. Choose Scatter Data


3.3. Example: Choose omnidirectional data




3.4. Enter data




3.5. Scatter data calculation




3.6. Make a condition




3.7. Study the results
Relation between the sea states and selected wind and current data 
Procedure

For each sea state, \(H_{s}\),\(T_{p}\) and \(\theta_{}\)

for all wind speed levels

interpolate to find wind speed and direction using \(H_{s}\) and \(T_{p}\)


for all current speed levels

interpolate to find current speed and direction using \(H_{s}\) and \(T_{p}\)


Use of profiles to find the current speed 
The current levels for different water depth can be calculated using the option From wind velocity
for Scatter Data
and Hind Cast Calculation
.
The current speed is estimated using the wind speed in a given Wind reference level
combined with two profile.

Wind Current Profile
, \(f_{w2c}(z)\) 
Base Current Profile
, \(f_{cbase}(z)\)
The
Base Current Profile
is multiplied with theBase Current Speed
, \(u_{mean}\)
