Coordinate Systems

Purpose

Explain how coordinate reference systems, projections, and grids determine where geospatial data lands on Earth.

Outline

• Geographic coordinates, projected coordinates, and datums
• Projection distortion in area, distance, shape, and direction
• Pixel grids, affine transforms, and alignment
• Reprojection, resampling, and analysis scale
• Common causes of misalignment between datasets

Later Examples

• Checking whether two layers align before analysis
• Comparing area estimates in different projections
• Resampling imagery onto a common grid