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Extract Terrain Keypoints

Overview​

Extracts terrain keypoints, such as peaks and valleys, based on the Gaussian filter coefficient.

Method​

The tool smooths the input DEM according to the Gaussian filter coefficient, identifies key terrain features, and writes the result to a new raster dataset. Output keypoint cells retain their original elevation values.

Use Cases​

  • Extract peaks, valleys, and other terrain keypoints for terrain interpretation.
  • Use terrain keypoints as intermediate data in a longer GIS processing workflow.
  • Improve efficiency in batch processing, repeatable analysis, or standardized delivery workflows.

Parameters​

ParameterDescriptionNotes
Input DEM raster fileInput digital elevation model (DEM) raster file.Required
Gaussian filter coefficientControls Gaussian smoothing strength. Recommended range: 0.5 to 2.0. Smaller values, such as 0.5 to 1.0, preserve more detailed features. Larger values, such as 1.5 to 2.0, produce stronger smoothing.Required; default: 1.0
Output keypoint raster fileOutput terrain keypoint raster file. Feature cells retain their original elevation values.Required

Steps​

  1. Start the tool: Open the Geoprocessing Toolbox, go to Thematic Analysis > Terrain Analysis, and start the Extract Terrain Keypoints tool.
  2. Prepare the input: Select the Input DEM raster file and confirm that the input data is complete and readable.
  3. Set core parameters: Configure the Gaussian filter coefficient according to the analysis objective.
  4. Set the output: Specify the Output keypoint raster file and confirm that the output path, format, and naming rules meet later workflow requirements.
  5. Run and inspect results: Click Run to execute the task. After it completes, check whether the result range, value distribution, and spatial location are as expected.

Notes​

  • When multiple rasters are used together, first confirm that their coordinate systems, resolutions, extents, and grid alignment are consistent.
  • Voids, noise, and abnormal elevation values in the DEM directly affect terrain factors such as slope, aspect, and curvature.