All products
Change Detection
Know what changed, where, and by how much — between any two dates.
change-detection
The problem
Large areas change constantly, and most of the change is irrelevant. Watching everything manually does not scale, so change is usually noticed late — after construction, after encroachment, after the damage.
How it works
Change Detection compares imagery from two or more dates, isolates real change from noise like season, illumination, and viewing angle, then classifies what kind of change occurred and measures it. Output is a set of change polygons, each with a type, an area, and both source images available for review.
Inputs
- Multi-temporal satellite or aerial imagery
- Area of interest
- Optional base layers: parcels, permits, land use
- The change classes you care about
Outputs
- Georeferenced change polygons with type and area
- Before and after imagery pairs per change
- Change statistics over time
- Alerts and periodic monitoring reports
Applications
- Construction and project monitoring
- Unpermitted construction and encroachment
- Urban expansion and land-use change
- Vegetation and environmental monitoring
- Demolition and site clearance tracking
In your GIS
Change polygons can be joined against permit or parcel layers, turning a stream of change into a much shorter list of changes that need attention.