Isis 3 Application Documentation
Creates cubes that have slope data or aspect data
Overview
Parameters
Example 1
Description
This program takes a cube in which the DN values represent elevations. This program
will calculate either the slope at every point, or the direction of the slope at
every point in radians or degrees. These directions are relative to the image (not
relative to north), which can be different in various projections and cameras.
Categories
History
Brian Peck 2006-12-25
Original version
Steven Lambright 2008-10-06
Changed slope and aspect algorithms
Parameter Groups
Files
Name
Description
FROM
Input cube
TO
Output cube
Options
Name
Description
OUTPUT Type of output requested
DEGREES Output in degrees
CONVERSION Conversion factor (resolution to meters)
Files :
FROM
Description
Use this parameter to select input cube. All bands of the cube within the file
will have the shade applied.
Type
cube
File Mode
input
Filter
*.cub
Files :
TO
Description
Output cube for your process.
Type
cube
File Mode
output
Pixel Type
real
Options :
OUTPUT
Description
This determines the type of output that will be created.
Type
string
Default
SLOPE
Option List:
Option
Brief
Description
SLOPE Create Slope Cube
This creates a slope cube. In other words, every DN value will
be set to its slope. The algorithm is explained
here .
ASPECT Create Aspect Cube
This creates an aspect cube. In other words, every DN value will
be set to the direction of the slope. The algorithm is explained
here .
Options :
DEGREES
Description
When set to true, the output image will be in degrees. If this is false,
the output image will be in radians.
Type
boolean
Default
false
Options :
CONVERSION
Description
Since the slope algorithm depends on cancelling out the units, the
conversion factor from the input unit to meters should be set. For
example, if the input image DN values mean kilometers, then this
value should be 1000 because there are 1000m in one kilometer.
Example 1
Creating an aspect cube
Description
This example creates an aspect (shows the direction of the slope) cube of Vallis Marinaris
Command Line
slpmap from=vallis_marinaris.cub to=aspect.cub output=aspect
In this examples we will create an aspect cube.
GUI Screenshot
Angle Gui
Example Gui
Screenshot of the GUI with parameters filled in to create a steepest slope cube.
Input Image
Input image
Image of Vallis Marinaris
Parameter Name:
FROM
This is our input image of Vallis Marinaris. The DN values are the angle, in radians, the slope is facing relative to the image.
Output Image
Output image showing angle cube.
The cube holding angle data
Parameter Name:
TO
This is the cube that holds the angle data.
