Analyse - Bathymetric tools
Bathymetric tools allow you to visualise and analyse the depth information of a dataset in the map view. How elevation model is calculated in GISGRO?
Bathymetric chart tool allows you to visualise the depth levels within your survey area region.
To get the chart visible on the map:
Activate the bathymetric chart tool from the top left corner menu.
Select the elevation model and the dataset from the drop-down menu or by clicking the area on the map.
You can select the auto-scale colormap option to use min and max values of the dataset
You can also set contours and soundings to be visible on the map.
For contours, you can set the wanted interval from the slider.
For the soundings you can use depth chart values or manually placed Z-values. Z-values have no relation to the selected elevation model. You can edit Z-values in 3D. Read more about it here.
There is an option to show both sounding types in nautical format.
Deactivate the tool by clicking the menu button again or by closing the panel.
Clearance depth tool is for highlighting depth deviation from the desired level. With the clearance depth tool, it is very easy to visualise under keel clearance in the surveyed area.
Activate the clearance depth tool from the top left corner menu.
Select the elevation model and the dataset from the drop-down menu or by clicking the area on the map.
Adjust the position of the reference level using the slider.
You can also choose contours and soundings to be visible on the map.
Deactivate the tool by clicking the menu button again or by closing the panel.
Comparison tool is for comparing two overlapping survey areas and visualising the difference between them.
Activate the comparison tool from the top left corner menu.
Select the elevation model and two overlapping datasets from the drop-down menu or by clicking the area on the map.
First, select the dataset with which you want to compare another dataset with.
Secondly, select the other dataset which you want to compare the firstly selected dataset with.
Define the maximum difference and the comparison width to visualise the difference between the datasets.
Deactivate the tool by clicking the menu button again or by closing the panel.
Export contours and soundings in DXF format by using the Export tool.
Select Export from the bathymetric tools in the top left corner menu.
Select the elevation model and the dataset from the drop-down menu or by clicking the area on the map.
Choose what you want to export and set the wanted interval for contours and spacing for soundings.
You can also set a different coordinate system unless you want the original one to be exported.
Export the files.
Deactivate the tool by clicking the menu button again or by closing the panel.
The adjustment of the sliders will not have a visual representation on the map, but the changes will be included in the exported file.
Volume calculation tool allows you to check the volume between a dataset and a set cut height or two dataset surfaces easily with just a few clicks.
Activate volume calculation from Bathymetric tools dropdown list
Select either Shallowest or Mean elevation model
Either import area as a DXF or draw it on top of the dataset
After the area has been defined, select the Reference surface
Cut height – calculate volume between a dataset and set cut height
Compare – calculate volume between two dataset surfaces
Control the reference surface
Cut height – Adjust wanted cut height from left side panel
Compare – Choose the comparison dataset from the drop down list
Preview or download full report from right side panel
Deactivate tool by clicking the tool icon or by pressing ESC
Note that you can also type in a value outside of the shown slider min/max values and this will be used in the calculation
Before you can import the DXF file, you need to select a coordinate system from the list
Volume calculation is based on Digital Elevation Model (DEM) that has been generated or included alongside inspections. A DEM is a raster – i.e. a grid of squares – where each grid cell has a height value. You can read more info on how the elevation model is calculated here. You can see the density of the DEM grid and other detailed parameters in the volume calculation report.
Once you have drawn the area of interest for volume calculation the tool will find all inspections that intersect with the selected area. You can adjust the wanted cut-off height by using the slider on the volume calculation tool. After changing the volume calculation parameters, the tool will calculate:
Red area/Cut volume: the area and volume above the given cut-off value
Green area/Fill volume: the area and volume below the given cut-off value
Empty area/Planar area N/A: the area where no elevation data was available.
If the area selection intersects with multiple inspections, the volume calculation process is repeated for every inspection and the total areas and volumes are summed up. Note that any overlapping inspections in the calculation area are included multiple times in the overall results. You can use the toggle switches for excluding or including inspections in the calculation.
Once you have drawn the area of interest for volume calculation the tool will find all inspections that intersect with the selected area. Select the dataset you want to use in the calculation and then choose the comparison dataset from the dropdown list. After selecting the datasets, the tool will calculate:
Red area/Cut volume: the area and volume above the comparison dataset surface
Green area/Fill volume: the area and volume below the comparison dataset surface
Empty area/Planar area N/A: the area where no elevation data was available.
The digital elevation models used by the system use the coordinate system of the respective inspection. Firstly, the selected calculation area is projected into the inspection’s coordinate system and the volume calculation is performed using that coordinate system. Lastly, the results are converted to metric values if necessary.
When the volume calculation has been completed, the calculation area on the map is also updated to reflect the area of the volume calculation.
Bathymetric chart, contours, and soundings
Bathymetric chart tool allows you to visualise the depth levels within your survey area region.
To get the chart visible on the map:
Activate the bathymetric chart tool from the top left corner menu.
Select the elevation model and the dataset from the drop-down menu or by clicking the area on the map.
You can select the auto-scale colormap option to use min and max values of the dataset
You can also set contours and soundings to be visible on the map.
For contours, you can set the wanted interval from the slider.
For the soundings you can use depth chart values or manually placed Z-values. Z-values have no relation to the selected elevation model. You can edit Z-values in 3D. Read more about it here.
There is an option to show both sounding types in nautical format.
Deactivate the tool by clicking the menu button again or by closing the panel.
Clearance depth
Clearance depth tool is for highlighting depth deviation from the desired level. With the clearance depth tool, it is very easy to visualise under keel clearance in the surveyed area.
Activate the clearance depth tool from the top left corner menu.
Select the elevation model and the dataset from the drop-down menu or by clicking the area on the map.
Adjust the position of the reference level using the slider.
You can also choose contours and soundings to be visible on the map.
Deactivate the tool by clicking the menu button again or by closing the panel.
Dataset comparison
Comparison tool is for comparing two overlapping survey areas and visualising the difference between them.
Activate the comparison tool from the top left corner menu.
Select the elevation model and two overlapping datasets from the drop-down menu or by clicking the area on the map.
First, select the dataset with which you want to compare another dataset with.
Secondly, select the other dataset which you want to compare the firstly selected dataset with.
Define the maximum difference and the comparison width to visualise the difference between the datasets.
Deactivate the tool by clicking the menu button again or by closing the panel.
Export soundings and contours
Export contours and soundings in DXF format by using the Export tool.
Select Export from the bathymetric tools in the top left corner menu.
Select the elevation model and the dataset from the drop-down menu or by clicking the area on the map.
Choose what you want to export and set the wanted interval for contours and spacing for soundings.
You can also set a different coordinate system unless you want the original one to be exported.
Export the files.
Deactivate the tool by clicking the menu button again or by closing the panel.
The adjustment of the sliders will not have a visual representation on the map, but the changes will be included in the exported file.
Volume calculation
Volume calculation tool allows you to check the volume between a dataset and a set cut height or two dataset surfaces easily with just a few clicks.
Activate volume calculation from Bathymetric tools dropdown list
Select either Shallowest or Mean elevation model
Either import area as a DXF or draw it on top of the dataset
After the area has been defined, select the Reference surface
Cut height – calculate volume between a dataset and set cut height
Compare – calculate volume between two dataset surfaces
Control the reference surface
Cut height – Adjust wanted cut height from left side panel
Compare – Choose the comparison dataset from the drop down list
Preview or download full report from right side panel
Deactivate tool by clicking the tool icon or by pressing ESC
Note that you can also type in a value outside of the shown slider min/max values and this will be used in the calculation
Before you can import the DXF file, you need to select a coordinate system from the list
More information on volume calculation
Volume calculation is based on Digital Elevation Model (DEM) that has been generated or included alongside inspections. A DEM is a raster – i.e. a grid of squares – where each grid cell has a height value. You can read more info on how the elevation model is calculated here. You can see the density of the DEM grid and other detailed parameters in the volume calculation report.
Reference surface – Cut height
Once you have drawn the area of interest for volume calculation the tool will find all inspections that intersect with the selected area. You can adjust the wanted cut-off height by using the slider on the volume calculation tool. After changing the volume calculation parameters, the tool will calculate:
Red area/Cut volume: the area and volume above the given cut-off value
Green area/Fill volume: the area and volume below the given cut-off value
Empty area/Planar area N/A: the area where no elevation data was available.
If the area selection intersects with multiple inspections, the volume calculation process is repeated for every inspection and the total areas and volumes are summed up. Note that any overlapping inspections in the calculation area are included multiple times in the overall results. You can use the toggle switches for excluding or including inspections in the calculation.
Reference surface – Compare
Once you have drawn the area of interest for volume calculation the tool will find all inspections that intersect with the selected area. Select the dataset you want to use in the calculation and then choose the comparison dataset from the dropdown list. After selecting the datasets, the tool will calculate:
Red area/Cut volume: the area and volume above the comparison dataset surface
Green area/Fill volume: the area and volume below the comparison dataset surface
Empty area/Planar area N/A: the area where no elevation data was available.
Further details
The digital elevation models used by the system use the coordinate system of the respective inspection. Firstly, the selected calculation area is projected into the inspection’s coordinate system and the volume calculation is performed using that coordinate system. Lastly, the results are converted to metric values if necessary.
When the volume calculation has been completed, the calculation area on the map is also updated to reflect the area of the volume calculation.
Updated on: 03/02/2025
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