Description
The AddSmoothedBand process adds a new smoothed elevation band to an existing coverage by applying smoothing operations to an existing elevation band. The Expand Shoals method pushes a distance-decaying value from all shoal points to expand spikes. The Laplacian method iteratively compares every point in the DEM to the weighted average of the surrounding neighbourhood, and raises all points that are deeper than their neighbourhood average.
Update
A raster or variable resolution surface in CSAR format.
Outputs
An updated raster or variable resolution surface in CSAR format.
Command Line Syntax
carisbatch --run AddSmoothedBand [options] <update>
User Interface Command
Add Smoothed Band
Options
The following table describes the parameters available for this process.
Parameter |
| |||
|---|---|---|---|---|
Long | Short | Description | Can Repeat | Notes
|
Common Options | ||||
--method | The algorithm applied to produce smoothed elevation values. • LAPLACIAN: Applies Ravi Peters iterative smoothing to the partitioned surface. • RESTRAINED_LAPLACIAN: Applies conservative Ravi Peters iterative smoothing to the partitioned surface. • EXPAND_SHOALS: Expands shoals to limit the steepness of the slope around them, producing a smoother surface. • CONSTRAIN_SLOPES: Updates the surface to ensure that no slope is steeper than a given constraint. • ROLLING_COIN: Uses disc-based smoothing to generalize around noise, producing a smoother surface. | FALSE | ||
--input-band | i | A string specifying the name of the input raster band that will be classified. This must be an elevation band. | FALSE | This must be specified explicitly. |
--smoothed-band | A string specifying the name of the output band. If an existing band is specified, values in that band are overwritten. | FALSE | This must be specified explicitly. | |
Method = LAPLACIAN Options | ||||
--iterations | The number of times the local averaging process is applied. The default value is 20. The value can be any number between 1 and 1000. The higher the number of iterations, the longer the processing time. | FALSE | ||
Method = RESTRAINED LAPLACIAN Options | ||||
--iterations | The number of times the local averaging process is applied. The default value is 20. The value can be any number between 1 and 1000. The higher the number of iterations, the longer the processing time. | FALSE | ||
Method = EXPAND_SHOALS Options | ||||
--radius-type | The type of radius used for smoothing. • FIXED: A single specified distance is used as the radius. • MULTIPLIER: A multiple of surface resolution is used as the radius. • HYBRID: The sum of a specified distance and a multiple of surface resolution is used as the radius. The default value is MULTIPLIER. The use of MULTIPLIER and HYBRID are most relevant when smoothing on a variable resolution surface. | FALSE | ||
--radius | A number and unit specifying the fixed distance component of the smoothing radius. The default value is 0.0m. The value can be any positive number. This value is ignored if RadiusType is MULTIPLIER. Supported units: cable, ch, cm, fm, ft, in, inm, km, m, mi, mm, nm, usfm, usft, usmi, usnm, usyd, yd. | FALSE | ||
--multiplier | A number specifying the resolution multiplier component of the smoothing radius. The default value is 5. The value can be any positive number. This value will be ignored if RadiusType is FIXED. | FALSE | ||
--radius-coefficients | The depth-dependent values used to add to the radius around each point. <LinearFactor> - A scale factor applied to depth values. Use CARIS:NONE or 0 to use a fixed radius. LinearFactor * depth is interpreted as a distance with the same unit as Radius. <QuadraticFactor> - A scale factor applied to the square of depth values. Use CARIS:NONE or 0 to use a fixed or linear radius. QuadraticFactor 2 * depth * depth is interpreted as a distance with the same unit as Radius. <DepthUnit> - Depth values are converted to this unit for this calculation. Defaults to m, i.e. metres. The following types of radii can be used: • Fixed radius = <Radius> and/or <Resolution>*<Multiplier> • Linear radius = (<Radius> and/or <Resolution>*<Multiplier>) + <LinearFactor> * depth • Quadratic radius = (<Radius> and/or <Resolution>*<Multiplier>) + <LinearFactor> * depth + <QuadraticFactor> * depth^2 If a depth value is negative, only the fixed radius (<Radius> and/or <Resolution>*<Multiplier>) is used. Supported units: cable, ch, cm, fm, ft, in, inm, km, m, mi, mm, nm, usfm, usft, usmi, usnm, usyd, yd | FALSE | ||
--isolations-only | If set, shoal points will only be expanded if they are shoaler than their immediate neighbourhood. If not set, slopes will be expanded as well. | FALSE | ||
--dropoff-slope | A negative number specifying the steepest allowed slope around shoals. The default value is -0.125. Values are unitless as they represent depth value decrease per unit of distance. | FALSE | ||
--scale | s | A number specifying the scaling applied to distance values (1:scale). The default value is 1, meaning that Radius will be treated as a ground distance. A scale of 1000 means that Radius is the radius of a shoal on a 1:1000 scale map. | FALSE | |
Method = CONSTRAIN_SLOPES Options | ||||
--vertical-rise | A number and unit specifying the maximum vertical distance of a slope. The default value is 10.0m. The value can be any positive number or zero. Supported units: cable, ch, cm, fm, ft, in, inm, km, m, mi, mm, nm, usfm, usft, usmi, usnm, usyd, yd. | FALSE | ||
--horizontal-run | A number and unit specifying the minimum horizontal distance of a slope. The default value is 10.0 m. The value can be any positive number. Supported units: cable, ch, cm, fm, ft, in, inm, km, m, mi, mm, nm, usfm, usft, usmi, usnm, usyd, yd, deg and rad. | FALSE | ||
--scale | s | A number specifying the scaling applied to distance values (1:scale). The default value is 1, meaning that Horizontal Run will be treated as a ground distance. A scale of 1000 means that Horizontal Run is treated as a distance on a 1:1000 scale map. Specifying a contour interval as Vertical Rise and a map distance as Horizontal Run can be used to guarantee a minimum spacing between contour lines. | FALSE | |
Method = ROLLING_COIN Options | ||||
--multiplier | A number specifying the resolution multiplier for the smoothing radius. The default value is 5. The value can be any positive number. | FALSE | ||
--radius-coefficients | The depth-dependent values used to add to the radius around each point. <LinearFactor> - A scale factor applied to depth values. Use CARIS:NONE or 0 to use a fixed radius. LinearFactor * depth is interpreted as a distance with the same unit as Radius. <QuadraticFactor> - A scale factor applied to the square of depth values. Use CARIS:NONE or 0 to use a fixed or linear radius. QuadraticFactor * depth * depth is interpreted as a distance with the same unit as Radius. <DepthUnit> - Depth values are converted to this unit for this calculation. Defaults to m, i.e. metres. The following types of radii can be used: • Fixed radius = <Resolution>*<Multiplier> • Linear radius = <Resolution>*<Multiplier> + <LinearFactor> * depth • Quadratic radius = <Resolution>*<Multiplier> + <LinearFactor> * depth + <QuadraticFactor> * depth^2 If a depth value is negative, only the fixed radius (<Resolution>*<Multiplier>) is used. Supported units: cable, ch, cm, fm, ft, in, inm, km, m, mi, mm, nm, usfm, usft, usmi, usnm, usyd, yd | FALSE | ||
To use this command, refer to the following examples.
Example: Expand Shoals Smoothing
Example | ||
|---|---|---|
Objective | You want to apply smoothing to a surface, expanding the size of shoals with a more gradual drop-off around them, before later creating smoother, hydrographically safe contours. | |
Description | Command Line Syntax | |
The EXPAND_SHOALS smoothing algorithm is to be applied. | --method EXPAND_SHOALS | |
The Depth band is to be smoothed. | --input-band Depth | |
The new band in which to store the smoothed values will be called DepthSmoothed. | --smoothed-band DepthSmoothed | |
A hybrid radius will be used for the smoothing. | --radius-type HYBRID | |
The radius distance is 5m. | --radius 5m | |
The resolution multiplier value is 4. | --multiplier 4 | |
The resulting slopes are to be no steeper than -0.25. | --dropoff-slope -0.25 | |
Smoothing will be applied to the SmoothSurface.csar coverage in the D:\BatchSample directory. | D:\BatchSample\SmoothSurface.csar | |
Command Line |
| |
Outcome | A new DepthSmoothed band is added to the input surface containing the smoothed elevation values. | |
Extra Notes | N/A | |
Example: Laplacian Smoothing
Example | ||
|---|---|---|
Objective | You want to apply smoothing to a surface to eliminate unnecessarily deep points and achieve a more uniform surface depth while maintaining the shoaler points. | |
Description | Command Line Syntax | |
The Laplacian smoothing algorithm is to be applied. | --method LAPLACIAN | |
The Depth band is to be smoothed. | --input-band Depth | |
The new band in which to store the smoothed values will be called DepthSmoothed. | --smoothed-band DepthSmoothed | |
The algorithm should be applied 30 times. | --iterations 30 | |
Smoothing will be applied to the LaplacianSurface.csar coverage in the D:\BatchSample directory. | D:\BatchSample\LaplacianSurface.csar | |
Command Line |
| |
Outcome | A new DepthSmoothed band is added to the input surface containing the smoothed elevation values. | |
Extra Notes | N/A | |
Example: Constrain Slopes Smoothing
Example | ||
|---|---|---|
Objective | You want to apply smoothing to a surface to eliminate unnecessarily steep slopes and achieve a more uniform surface depth while maintaining the shoaler points. | |
Description | Command Line Syntax | |
The Constrain Slopes smoothing algorithm is to be applied. | --method CONSTRAIN_SLOPES | |
The Depth band is to be smoothed. | --input-band Depth | |
The new band in which to store the smoothed values will be called DepthSmoothed. | --smoothed-band DepthSmoothed | |
The resulting slopes are to be no steeper than 5 metres. | --vertical-rise 5m | |
The resulting slopes are to be at least 10 metres wide. | --horizontal-run 10m | |
Smoothing will be applied to the ConstrainedSlopes.csar coverage in the D:\BatchSample directory. | D:\BatchSample\ConstrainedSlopes.csar | |
Command Line |
| |
Outcome | A new DepthSmoothed band is added to the input surface containing the smoothed elevation values. | |
Extra Notes | N/A | |