In this section:
Introduction
CUBE (Combined Uncertainty and Bathymetric Estimator), is an error-model based, direct DTM generator that estimates the depth plus a confidence interval directly on each node point. The CUBE library is developed by University of New Hampshire.
The implementation in Geocap Seafloor is modfied to work with echo sounder models whic were not in the market when Cube was created. Tha latest release of the Cube library was in 2004.
The output of the command is a depth surface named cube_depth_surface. The surface can also contain additional attributes like Uncertainty, DepthHypotheses and HypothesisStrength dependent on the selected options in the dialog.
The content of the menu
The CUBE dialog for multibeam data and CUBE for XYZ data in a Soundings folder.
Input Data
The Input data part of the dialog is where to select which data items to be gridded. The CUBE command works with both multibeam data (Survey Line) and with XYZ data (Dataset). Select data items from the list.
The rows X, Y and Z are automatically updated with the minimum and maximum extensions of the coordinates from the selected files.
The Coordinate System field shows the type of coordinate system for the data.
Cube Algorithm Parameters
The Cube Algorithm Parameters part is where to specify parameters for the CUBE depth processing. The parameters to set:
- Depth Estimation Algorithm
- Grid increments
- Error Distribution Model Algorithm
Depth Estimation Algorithm
The options for the depth estimation algorithm are:
- Compute depths based on nodal estimate algorithm: This is the default algorithm for the implementation og Cube. it will create the depth surface and the operator can select to also create the Uncertainty attributes to the cube_depth_surface.
- Compute depths based on bined mean algorithm: This algorithm will create the surface based on the mean values in the bins (cells). No attributes can be created.
- Compute depths based on bined median algorithm:This algorithm will create the surface based on the median values in the bins (cells). No attributes can be created.
- Compute depths using the HyperCUBE super-grid: The HyperCUBE super-grid is creating a grid based on several hypotheses from the depth data. In addition to the depth grid this algorithm can also create the attributes DepthHypotheses and HypothesisStrength as output in the cube_depth_surface.
Grid increments
Error Distribution Model Algorithm
the gives information of which surface the command is started from. Select a Poly Data or Structured Points (surface) data set in the project and click the 
button beside the text field.
When starting the volumetrics with a Poly Data set as input, the ply data will be triangulated to a surface model. The better the polygon describes the actual cut surface the better the result the volumetrics calculation will be. The surface created from the poly data is named as the Cut surface.
The calculation of the volumes is done by subtracting the cut surface from the Terrain surface to get the difference surface.
Output
Select options for whatCreate the cut surface from polygon data set.
The surface is saved with the name CutSurface in a subfolder named Volumetrics in the same folder as the terrain surface is located.
The Results
After executing the volumetrics a dialog will pop up showing the parameters, result and volumes from the calculations. The report itself is saved in the project structure in a folder named Reports under the same folder as the command is executed from. The report itself is named as YYYYMMDD CUBE (the name of the executed command).
All reports from all runs will be saved in the Reports folder.