Change on the earth's surface can occur because of human activity, abrupt natural disturbances, or long-term climatological or environmental trends. Detecting that change is one of the fundamental applications in imagery and remote sensing. Change detection is the comparison of multiple raster datasets, typically collected for one area at different times, to determine the type, magnitude, and location of change. This can take the form of image-to-image change detection, or change detected across a stack of images or time series of images.
ArcGIS provides a variety of tools to perform change detection. The Change Detection toolset in ArcGIS Pro contains tools that perform change detection between raster datasets. ArcGIS Pro also includes the Change Detection Wizard, which combines tools and functions to guide you through three possible change detection workflows:
- Categorical change, which identifies the type of change between two thematic or categorical rasters, such as land cover
- Pixel-value change, which calculates the difference in pixel values between two continuous rasters, such as temperature rasters or multiband imagery
- Time-series change, which identifies the date of change in a time series of images using either the Continuous Change Detection and Classification (CCDC) method or the Landsat-based Detection of Trends in Disturbance and Recovery (LandTrendr) method
Change detection can also be scaled up using distributed processing with ArcGIS Enterprise and ArcGIS Image Server.
Explore the following resources to learn more about change detection in ArcGIS.
Note:
To work with the Change Detection Wizard and tools and raster functions in ArcGIS Pro, you need ArcGIS Image Analyst. To work with the change detection tools through ArcGIS REST API or ArcGIS Enterprise, you need ArcGIS Image Server.
ArcGIS help
Review the following links on reference materials for ArcGIS products:
- Read an overview of change detection in ArcGIS Pro, including tools and functions.
- Read about the Change Detection toolset in ArcGIS Pro.
- Read an overview of the Change Detection Wizard.
- Read about categorical change detection in ArcGIS Pro, which identifies the type of change that has occurred between two thematic or categorical rasters.
- Read about pixel-to-pixel change detection in ArcGIS Pro, which identifies differences in continuous data, such as optical imagery or modeled data, on a pixel-by-pixel basis.
- Read about time-series change detection in ArcGIS Pro, which models a pixel's history over many images to find the date when change occurred.
- Read about the Pixel Time Series Change Explorer, which allows you to generate a chart that identifies changes in a single pixel value over time using the CCDC or LandTrendr method.
ArcGIS blogs, articles, story maps, and technical papers
Review the following supplemental guidance about concepts, software functionality, and workflows:
- In this blog, read about using the change detection wizard to evaluate land cover and vegetation changes in Ethiopia.
- Read this blog to learn about two algorithms for performing time series change detection: CCDC and LandTrendr.
Videos
Review the following Esri-produced videos that clarify and demonstrate concepts, software functionality, and workflows:
- Watch this video to see how to monitor change in the environment using time-series imagery. (3 minutes)
- Watch an overview of the Change Detection Wizard. (4 minutes)
- Watch a video showing how to extract long-term change information using the LandTrendr algorithm. (6 minutes)
- Watch a demo theater introducing change detection tools in ArcGIS Pro. (28 minutes)
Training and tutorials
Review the following guided lessons and tutorials based on real-world problems and key ArcGIS skills:
- Use the Change Detection Wizard in ArcGIS Pro to analyze different types of land cover change in Ethiopia. (50 minutes)
- Assess hail damage in cornfields using satellite data and the pixel-to-pixel change workflow in ArcGIS Pro. (30 minutes)
Developer resources
Review the following resources and support for automating and customizing workflows:
- Review the raster analysis service tasks, such as the Compute Change Raster task, which is used to evaluate the difference between two input rasters and generate a change raster output service.
Esri Community
Use the online imagery community to connect, collaborate, and share experiences:
- Visit the Esri Imagery and Remote Sensing community to connect, collaborate, and share experiences regarding image change detection.