CSV Editor

CSV Editor is used to prepare input bathymetry data for use in dBSea. It reads raster and vector data in a variety of formats and writes an ESRI ASCII grid ready to be loaded with Tools → Load bathymetry. Since version 3.0.14 it is built into dBSea and opened from Tools → CSV Editor. For information on the bathymetry formats dBSea reads directly, see the page Importing bathymetry.

Consider using dedicated GIS software

All of the operations described here can be performed with greater flexibility and capability in dedicated GIS software such as ArcGIS, QGIS, or similar. CSV Editor is included as a convenience utility to assist users who do not have access to GIS tools, and has very limited functionality by comparison.

When do you need CSV Editor?

dBSea imports raster formats (GeoTIFF, ESRI ASCII grid, gridded CSV) directly — no conversion needed. CSV Editor is primarily needed when your bathymetry data is in a vector format such as XYZ point data or shapefiles. In that case, CSV Editor converts the vector points to a raster grid (via Delaunay triangulation) that dBSea can use. If you have a choice of source format, prefer raster data to skip this step entirely.

Importing raster data

Choose a data file (.csv, .asc or .txt) with the Open raster file button. The whole file is read at once and the delimiter (comma, semicolon or space) is detected automatically; the File info panel shows the number of lines and fields per line, and the ESRI Grid Info panel shows the columns, rows, easting, northing and cell size where the file provides them. Values outside the Max depth and Max height limits (12 000 m by default) are treated as unsurveyed. A value of 0 is a depth of 0 m; negative values are land heights.

If the file is in latitude and longitude, or has no coordinate information, UTM zone options lets you enter the UTM zone (e.g. 30U) to use.

Importing vector data

CSV Editor is able to import and convert vector data in .shp (ESRI shapefile) or .xyz (text XYZ points) formats with the Import vector file button. For more information, see the page CSV Editor Vector Import.

Translating data

The Translate buttons Reverse E-W, Reverse N-S and Rotate CW 90 reorient a grid whose rows or columns run the wrong way, and Swap heights/depths changes the sign of every value for data that uses positive-up heights.

Editing terrain

Left-click and drag in the data image area to select a rectangular area, or right-click to place the corners of a polygon. With an area selected, enter a value in Depth: and use Raise terrain, Lower terrain or Set to depth; Select all selects the whole grid and Reset terrain edits removes all changes. Moving the mouse over the image area shows the current depth at the cursor location.

Reducing file size

Large files may be reduced with Decimate (downsample). Enter a decimation factor m (2 or more); each output cell is the average of the surveyed cells in an m × m block of input cells, and the result is saved as an ESRI ASCII grid.

Selecting and exporting a range

The selection rectangle shows the area of bathymetry that will be exported. To alter it, enter values in the Export range x/y boxes or right-click and drag in the image area; Reset range restores the full extent. Export selection writes the selected area as an ESRI ASCII grid (.asc), which may then be loaded in dBSea with Tools → Load bathymetry. Create XYZ file writes the data as points instead.

Troubleshooting

See the CSV Editing Troubleshooting page for more help.