Video Lecture
Watch the lecture video for this module. Runtime: approximately 55 minutes.
Lecture Slides
Lecture Notes
Two Ways to Represent the World
GIS uses two fundamental data models to represent geographic features:
Vector Data
Uses discrete points, lines, and polygons to represent features with clear boundaries.
- Points: Cities, fire hydrants, sample locations
- Lines: Roads, rivers, power lines
- Polygons: Countries, parcels, lakes
Raster Data
Uses a continuous grid of cells (pixels) to represent surfaces and imagery.
- Satellite imagery
- Elevation models (DEMs)
- Temperature/precipitation surfaces
- Land cover classification
Coordinate Systems
Every GIS dataset must have a defined coordinate system to accurately locate features on Earth.
- Geographic Coordinate Systems (GCS): Use latitude and longitude (degrees) on a 3D spheroid. Example: WGS 1984.
- Projected Coordinate Systems (PCS): Flatten the Earth onto a 2D plane using mathematical transformations. Measured in feet or meters. Examples: UTM, State Plane.
Map Projections
All map projections involve trade-offs. They can preserve:
- Shape (conformal) - Mercator
- Area (equal-area) - Albers
- Distance (equidistant) - Azimuthal Equidistant
- Direction - Gnomonic
No projection can preserve all properties simultaneously!
Common File Formats
| Format | Type | Description |
|---|---|---|
| Shapefile (.shp) | Vector | Most common exchange format (actually 3-7 files) |
| GeoJSON | Vector | Web-friendly format based on JSON |
| File Geodatabase | Both | Esri's modern native format |
| GeoTIFF | Raster | TIFF image with embedded georeferencing |
| GeoPackage | Both | Open standard, SQLite-based |
Lab Assignment
Lab 1: Exploring GIS Data in ArcGIS Pro
Objectives
- Navigate the ArcGIS Pro interface
- Add and explore vector and raster data
- Examine attribute tables
- Change map projections and observe distortion
- Create a simple map layout
- Lab 1 Instructions (PDF) 1.2 MB
- Lab 1 Data Package (ZIP) 45 MB
- Lab 1 Submission Template (Word) 85 KB
Due Date
Friday, January 24 at 11:59 PM
Submit via D2L Dropbox. Late submissions will lose
10% per day.