Non standard features

2. Velgrid interpolation dialog - Non standard features

These non-standard feature are described schematically in Diagram D - Use of Velgrid.

2A - Bathymetry file from Hydrodynamic Model (HM) - Use this feature and specify bathymetry

This feature is used to generate files containing bathymetry information. It does not interpolate bathymetry data, it creates a file containing the longitude, latitude and depth of each grid node on the uninterpolated grid. To use this feature, click the check box and specify the number of header lines. These header lines are ignored by Velgrid and the information in the header lines is not used. Orientation of the grid is true north up (i.e. orientated with latitude and longitude).

Specify the bathymetric input file which contains depth (in metres) for each grid node. The grid should have ni columns and nj rows specified for the uninterpolated grid (1C).

Example file	Description	File format	I/O?
velgridinstalldir\Example files\Velocity grids\sitename2\bathy\fiu_bathy.dat	Uninterpolated bathymetry data from hydrodynamic model	Space	I
	{Header line - ignored by Velgrid} {Header line - ignored by Velgrid} {Header line - ignored by Velgrid} {Header line - ignored by Velgrid} depth(1, nj) .. depth(ni, nj) .. depth(1,1) .. depth(ni, 1)

Example file	Description	File format	I/O?
velgridinstalldir\Example files\Velocity grids\sitename2\bathy\fiu_bathy_grid.csv	Calculated node positions using Grid size and position information (longitude and latitude) - this file can be used to check calculated node positions for the uninterpolated grid	CSV	O
etc. then	Longitude (1, nj) .. Longitude (ni, nj) .. Longitude (1,1) .. Longitude (ni, 1) Latitude (1, nj) .. Latitude (ni, nj) .. Latitude (1,1) .. Latitude (ni, 1)

Example files	Description	File format	I/O?
velgridinstalldir\Example files\Velocity grids\sitename2\bathy\fiu_bathy_xyz.csv	Calculated node positions and depth using Grid size and position information - this file can be used in contouring software	CSV	O
etc.	{Header line - ignored by Velgrid} Longitude (1, nj), Latitude (1, nj),Depth(m)(1, nj) .. Longitude (ni, nj), Latitude (ni, nj),Depth(m)(ni, nj) Longitude (1, nj-1), Latitude (1, nj-1),Depth(m)(1, nj-1) .. Longitude (ni, nj-1), Latitude (ni, nj-1),Depth(m)(ni, nj-1) etc. Longitude (1, 1), Latitude (1, 1),Depth(m)(1, 1) .. Longitude (ni, 1), Latitude (ni, 1),Depth(m)(ni, 1)

2B - Write an output file containing uninterpolated data

Specify a name in the box to create a file which contains uninterpolated velocity u and v components. This feature can be used to check Velgrid interpolations, when used in conjunction with 2C - Create grids which are not spatially varying and use the position below.

Example files	Description	File format	I/O?
velgridinstalldir\Example files\Velocity grids\sitename2\surface\fiu_sur_0347_A_xyz.csv	Uninterpolated velocity u and v components at each grid node - these are data from files specified in 1M in an XYZ file suitable for contouring	CSV	O
	Longitude (i, j), Latitude (i, j),u(cm/s)(i, j), v(cm/s)(i, j), i, j

2C - Create grids which are not spatially varying and use the position below

This feature can be used to create non-spatially varying grids at a specified latitude and longitude. A time series in a CSV file can also be created with specified time and date, where the output files for each time step are combined into this file. Give the file a name.

When non-spatially varying grids are created, the name must also be changed for the .prn files, otherwise, previous interpolations undertaken for each node will be overwritten. Therefore, change the Name below to match the Name specified above as shown in the example:

This feature can be used to check interpolations of Velgrid as follows:

1. Create grids using this feature.
2. Write an output file containing uninterpolated data (2B).
3. Now compare the interpolated data at the specified position with the four nearest nodes to it in the uninterpolated data created in step 2. For example, the four nearest nodes to position 56.55907 Lat and -5.919333 Long are:

(50,71) (51,71)
(50,70) (51,70)

Using uninterpolated u and v from these node positions, the predictions of Velgrid can be verified.

Example file	Description	File format	I/O?
velgridinstalldir\Example files\Velocity grids\sitename2\surface\fiu_sur_0347_Unint_interpol.prn	File containing non-spatially varying grids, with interpolated data for a particular position repeated for each node.	Space	O
	{Header line - ignored by Velgrid} u(1, nj) .. u(ni, nj) .. u(1,1) .. u(ni, 1) v(1, nj) .. v(ni, nj) .. v(1,1) .. v(ni, 1)

Example file	Description	File format	I/O?
velgridinstalldir\Example files\Velocity grids\sitename2\surface\fiu_sur_0347_Unint_timeseries.csv	Interpolated velocity u and v components at a specified position - all output files from 1M are combined into one time series.	CSV	O
	t,date time,u(t),v(t),Name,Latitude,Longitude

2D - Creating a grid with zero current velocity

An area of the grid can be created containing zero current velocity, useful for creating imaginary deposition centres in the grid. Zero current may be specified outside or inside specified limits.

The name of the output velocity grid files must also be changed. e.g.:

For specifying zero current inside limits:

The name of the output velocity grid files must also be changed. e.g.:

Example file	Description	File format	I/O?
velgridinstalldir\Example files\Velocity grids\sitename2\surface\fiu_sur_0347_ZeroIn_interpol.prn	File containing spatially varying grids, with an area of zero current specified inside limits.	CSV	O
	{Header line - ignored by Velgrid} u(1, nj) .. u(ni, nj) .. u(1,1) .. u(ni, 1) v(1, nj) .. v(ni, nj) .. v(1,1) .. v(ni, 1)

Example file	Description	File format	I/O?
velgridinstalldir\Example files\Velocity grids\sitename2\surface\fiu_sur_0347_ZeroOut_interpol.prn	File containing spatially varying grids, with an area of zero current specified inside limits.	CSV	O
	{Header line - ignored by Velgrid} u(1, nj) .. u(ni, nj) .. u(1,1) .. u(ni, 1) v(1, nj) .. v(ni, nj) .. v(1,1) .. v(ni, 1)

Diagram A - Overview of AutoDEPOMOD (AD) version 3
Diagram B - Use of Velgrid
Diagram C - Creation of Velgrid INI file
Diagram D - Additional features of Velgrid

Getting started and contents