Analytical Hillshade
Combines local slope/aspect with illumination geometry.
H = 255[cos Z·cos S + sin Z·sin S·cos(Asun−Aslope)]
Best used when: terrain visualization and qualitative relief interpretation are needed.
Hillshade
Simulate terrain illumination from a chosen light azimuth and altitude using DEM slope and aspect.
Terrain / ElevationEnd-User DocumentationTheory + Formula + Parameters1. What This Feature Does
Simulate terrain illumination from a chosen light azimuth and altitude using DEM slope and aspect.
Cloud workflow: choose data → configure the scientific method → run → review the resulting layer/report. No programming is required.
2. Recommended Workflow
Choose DEM band.
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Set sun/light azimuth and altitude.
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Set vertical exaggeration if available.
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Generate hillshade.
3. Theory, Methods & Equations
4. Input Data
| Input | Type | Requirement | Description |
|---|---|---|---|
| DEM Raster | raster | Required |
5. Parameters Available in the Application
| Parameter | Default | Choices / Range | How to Use It |
|---|---|---|---|
| Elevation Band | — | — | |
| Sun Azimuth | 315 | 0 to 360 | |
| Sun Altitude | 45 | 0 to 90 | |
| Z Factor | 1 | 1e-06 to — |
6. Output & Interpretation
The result should be interpreted according to the selected method and the physical meaning of the input data. Preserve source units, coordinate reference information, NoData meaning, acquisition date, and preprocessing level when comparing results.
Scientific interpretation: an algorithm can produce a numerically valid result even when the input data are unsuitable. Always check masks, units, sensor characteristics, spatial resolution and reference data.
Important: Hillshade is a visualization, not elevation. Dark cells are not necessarily low terrain.
7. Best Practices
- Use analysis-ready inputs and remove invalid/cloud/noise artifacts that are not part of the target phenomenon.
- Choose parameters from the physical scale of the data, not only from visual appearance.
- Keep categorical and continuous rasters conceptually separate when selecting interpolation/resampling methods.
- Compare the result with the source image and independent reference information.
- Document the settings used when results will be compared across dates, sensors or study areas.