Today, I will explore raster datasets in ArcGIS Online and compare what they show to vector data.
I can add a raster layer in ArcGIS Online, describe the information it shows, and explain one strength and one limitation of rasters compared to vectors.
Rasters and vectors show the world in different ways. Practicing with rasters helps us understand how patterns like land cover, vegetation, or elevation are represented — and why perspective matters in data.
💡 Think back to Julia’s lesson yesterday. What’s one thing about rasters that made sense to you, and what’s one thing you still want to understand better?
| Term | Definition | Example | Why It Matters |
|---|---|---|---|
| Land Cover Raster | Grid showing forest, water, urban, etc. | Satellite data classifying ground surfaces. | Helps track environmental change. |
| DEM (Digital Elevation Model) | Raster storing elevation values in cells. | Hillshade map of mountains. | Key for flood planning, 3D terrain. |
| Resolution | Size of each raster cell/pixel. | 10m vs 30m elevation grid. | Impacts accuracy and detail. |
✅ Check for Understanding #1
Ask: What does the raster show clearly that the vector doesn’t?