View source for Generation and Modification of Computational Grids

[[de:Erzeugung und Bearbeitung von Gitternetzen]]
Remark: [[JANET]] covers many functions related to grid generation and grid modification.

This page gives you a comprehensive overview about all other programs actually used at BAW-DH for the purpose of grid generation and grid modification and with a functionality not covered by JANET.

==Complex Workflows==

===Renewal of Bathymetry for Finite Difference Grids ([tr2.]topo.bin)===

[http://www.baw.de/downloads/wasserbau/mathematische_verfahren/pdf/fd-upd-2.pdf Graphical representation] of the complex workflow concerning the renewal of bathymetry for various finite difference grids (filtype [[TOPO.BIN|topo.bin]]  and [[TR2.TOPO.BIN|tr2.topo.bin]]). This figure is also available as a [http://www.baw.de/downloads/wasserbau/mathematische_verfahren/eps/fd-upd.eps PostScript file]. 

===Conversion between various Grid File Formats===

[http://www.baw.de/downloads/wasserbau/mathematische_verfahren/pdf/git-kon-2.pdf Graphical representation] of several existing conversion possiblities beetween different grid-file formats, also available as [http://www.baw.de/downloads/wasserbau/mathematische_verfahren/eps/git-kon-21.eps PostScript file].

==Model-Independent Preprocessing==

===Modification and Display of Topographic Data===

* [[SYNGRID]]: Generation of artificial bearing data (e.g. along circles).
* [[DATAUS]]: Selection of topographic data within an area defined by a surrounding polygon. This program is useful for many many topographic data points.

===Boundary Polygon===

[[IGEL2D]]: Interactive generation of a boundary polygon for a set of (selected) topographic data points. 

===Fairway Dredger Grid===

[[TRASSE]]: Generation of nodal points for a fairway dredger grid. From these nodal points a FE-grid may be generated by means of triangulation.

===Extraction of depth isolines===

[[VOLUMETH]]: Extraction of depth isolines out of an FE grid (filetype [[GITTER05.DAT and GITTER05.BIN|gitter05.dat/bin]]).

===Conversion of Grid Files===

Several types of grid files are currently used at BAW-DH. The following file types are supported:

#FD-grid of type FIDISOR/FIDIRB
#:filetype [[TOPO.BIN|topo.bin]].
#FD-grid of type TRIM
#:filetype [[TR2.TOPO.BIN|tr2.topo.bin]]. and [[TR2.TOPO.BIN.IND|tr2.topo.bin.ind]].
#FE-grid of type TICAD
#:filetype [[GITTER05.DAT and GITTER05.BIN|gitter05.dat/bin]].
#FE-grid of type SELAFIN
#:filetype [[SELAFIN|selafin]].

==Graphic Display of Computational Grids==

The following programs are currently available to display FE- and FD-grids:

* [[FDGITTER05]]: graphic display for filetype [[TOPO.BIN|topo.bin]].
* [[TRGITTER05]]: graphic display for filetype [[TR2.TOPO.BIN|tr2.topo.bin]].
* RGFGRID (Delft3D): graphic display for filetype [[DELFT3D.GRD|delft3d.grd]].

==Preprocessing for Finite Difference Models==

The numerical models based on finite differences which are mainly used at BAW-DH are the two-dimensional model [[TRIM-2D]] as well as the three-dimensional model [[TRIM-3D]]. To generate the grid files for both aforementioned models several programs are can be used.

===Generation of a Computational Grid===

* gridfile of type FIDISOR/FIDIRB:
:*[[FD2BASIS]]: generation of a basic FD-grid (filetype [[TOPO.BIN|topo.bin]]) with correct land/water distribution from digitized boundary structures
:*[[TC2GEOM]]: generation of a FD-grid (filetype [[TOPO.BIN|topo.bin]]) from a digital terrain model, which is based on a FE-grid (filetype [[GITTER05.DAT and GITTER05.BIN|gitter05.dat/bin]]).
:*[[TR2FIDI]]: generation of a FD-grid (filetype [[TOPO.BIN|topo.bin]]) from an existing FD-grid (filetype [[TR2.TOPO.BIN|tr2.topo.bin]]).
* gridfile of type TRIM:
:*[[FD2TRIM]]: generation of a FD-grid (filetype [[TR2.TOPO.BIN|tr2.topo.bin]]) from an existing FD-grid (filetype [[TR2.TOPO.BIN|tr2.topo.bin]]).
:*[[TR2GEOM]]: generation of a FD-grid (filetype [[TR2.TOPO.BIN|tr2.topo.bin]]) from a digital terrain model, which is based on a FE-grid (filetype [[GITTER05.DAT and GITTER05.BIN|gitter05.dat/bin]])

===Manipulation of Computational Grids===

* gridfile of type FIDISOR/FIDIRB:
:*FD2CUT: Cutting a (small area) partial grid out of a complete grid.
:*[[FD2DEL]]: Calculating differences of bathymetry by comparing two existing bathymetries stored on two different FD-grids or, alternatively, modification of an existing bathymetry with earlier calculated differences of bathymetry.
:*FD2DTOP: Conversion for differences of bathymetry (generated by the program FD2DEL) into a FD-gridfile (filetype [[TOPO.BIN|topo.bin]]).
:*[[FD2KACHEL]]: Cutting a small part of a grid from a complete gridfile, also in combination with numerically calculated results.
:*[[FD2MOD]]: Generation of modified differences of bathymetry out of regular differences of bathymetry which have been generated by the program FD2DEL before.
:*[[FDGLUE]]: Glue together two originally different grids to form one large new grid.
:*TOP2IN1: Insertion of a small grid into a large grid.
* gridfile of type TRIM:
:*[[TR2KACHEL]]: Cutting a small part of a grid from a complete gridfile, also in combination with numerically calculated results.

===Modification of Bathymetry===

* gridfile of type FIDISOR/FIDIRB:
:*[[FD2ADDTOPO]]: Update a FIDISOR/FIDIRB topography with data from echo soundings under constraints of digitized structures.
:*FD2BAGGER: Deepening of bathymetry (dredging of material).
:*FD2REM: Deletion of structures (e.g. groynes, dams) from a FD-grid.
:*[[FD2RIBA]]: Deepening of bathymetry (dredging of material), but taking into account the effect of dunes or deep areas.
:*FD2SPUELER: Reducing bathymetrical depths (disposal of material).
:*FD2WEVO: Inversion of the sign (from plus to minus or vice-versa) for the bathymetrical depths.
:*[[GEOMFD2]]: Generation of a grid out of a set of (representative) topographic data points. The format of the grid file is FIDISOR/FIDIRB (filetype [[TOPO.BIN|topo.bin]]).
* gridfile of type TRIM:
:*[[TR2REFRESH]]: Modify (refresh) bathymetry of a FD-grid with bathymetry given as a digital terrain model defined on an FE-grid (filetype [[GITTER05.DAT and GITTER05.BIN|gitter05.dat/bin]]). Different special actions are available to modify bathymetry, e.g. dredging or disposal of material.

===Calculation of Volumes and Areas===

* gridfile of type FIDISOR/FIDIRB:
:*[[FD2HYPSO]]: Determination of the frequency distribution for bathymetrical depth of a FD-grid.
:*FD2DREV: Determination of dredged volumes.

==Preprocessing for Finite Element Models==

[[TELEMAC-2D]] is based on the finite element method and used at BAW-DH.

===Generation of a Computational Grid===

* gridfile of type TICAD (gitter05.dat/bin):
:*[[GRIDCONVERT]]: Conversion from an existing grid file (filetype [[SELAFIN|selafin]]).
:*[[JANET]]: Generation of an FE-grid out of point or polygon data or conversion from an existing grid file (filetypes [[SELAFIN|selafin], [[UNTRIM_GRID.DAT|untrim_grid.dat]] and [[TR2.TOPO.BIN|tr2.topo.bin]] are possible).
:*FD2GEOM: Generation of an FE-grid from an existing FIDISOR/FIDIRB grid (filetype [[TOPO.BIN|topo.bin]]).
:*[[TR2GEOM]]: Generation of an FE-grid from an existing TRIM grid (filetype [[TR2.TOPO.BIN|tr2.topo.bin]]).
* gridfile of type SELAFIN (selafin):
:*[[JANET]]: Generation of an FE-grid out of point or polygon data or conversion from an existing grid file (filetypes [[GITTER05.DAT and GITTER05.BIN|gitter05.dat/bin]], [[UNTRIM_GRID.DAT|untrim_grid.dat]] and [[TR2.TOPO.BIN|tr2.topo.bin]] are possible).

===Manipulation of Computational Grids===

* gridfile of type TICAD:
:*[[DIDASPLIT]]: Cutting of a grid into tiles, also in combination with calculated data stored in the well known BDF-Format (description available in German only).
:*[[KACHEL2D]]: Cutting a partial grid out of a complete grid.

===Modification of Bathymetry===

*gridfile of type TICAD:
:*[[TC2BAGGER]]: Dredging and disposal of material.
:*[[UPDA2D]]: Modify bathymetric depths on a FE-grid using (selected) topographic data points.

===Calculation of Volumes and Areas===

*gridfile of Type TICAD:
:*[[TOPVF]]: Calculation values for 2D- as well as 3D-areas which are lying in between two different horizontal planes.
:*[[VOLUMETH]]: Calculation of area distribution and volume sum function of a region inside an FE mesh.

==Preprocessing for unstructured orthogonal grid Models==

At BAW-DH we use an unstructured orthogonal grid method: [[UNTRIM]]. The grid generator [[JANET]] is fitted to the needs of this method. It is therefor no surprise that many grid functions useful for this method are integrated in JANET.

===Generation of Grids (filetype [[UNTRIM_GRID.DAT|untrim_grid.dat]])===

* [[GRIDCONVERT]]: Conversion from an existing grid file (filetypes [[DELFT3D.GRD|delft3d.grd]], [[GITTER05.DAT and GITTER05.BIN|gitter05.dat/bin]] or [[SELAFIN|selafin]] are possible).
* [[JANET]]: Generation of an UNTRIM-grid out of point or polygon data or conversion from an existing grid file (filetypes [[GITTER05.DAT and GITTER05.BIN|gitter05.dat/bin]], [[SELAFIN|selafin]] or [[TR2.TOPO.BIN|tr2.topo.bin]] are possible).
* [[TOUTR]]: Conversion from an existing grid file (filetypes [[TR2.TOPO.BIN|tr2.topo.bin]] or [[GITTER05.DAT and GITTER05.BIN|gitter05.dat/bin]]).   
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