Georeferencing
Definition
The process of assigning real-world coordinates to a raster image or survey grid using known control points. A ground-penetrating radar grid, for example, is georeferenced by matching survey pin positions in the data to their GPS coordinates in the GIS.
- Purpose
- Assign real-world coordinates to a raster or grid
- Method
- Matching known control points
- Example
- GPR survey grid aligned to GPS pin positions
- Field
- GIS integration for search management
Common questions
Why is georeferencing necessary before analyzing survey data in GIS?+
Without real-world coordinates, survey grid data exists only in its own local reference frame and cannot be accurately overlaid with maps, other survey data, or GPS-recorded features.
What happens if the control points used are inaccurate?+
Positional error in the control points propagates into the final map, potentially misplacing anomalies or evidence relative to their true ground position.
Can georeferencing be applied to historical maps, not just survey grids?+
Yes, the same control-point matching process is commonly used to align old maps, aerial photographs, or scanned documents to a modern coordinate system for comparison over time.
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