OpenTopography is pleased to announce a visualization enhancement for topographic differencing results that allows users to visually compare the change between two overlapping datasets using an image slider to compare hillshades. This slider is produced by default for all differencing jobs and is displayed at the bottom of the results page. In regions with multi-temporal lidar coverage, topographic differencing can be used to quantify the change in the surface environment for a variety of tectonic, geomorphic, and anthropogenic processes including earthquakes, volcanic eruptions, river erosion, landslides, sand dune migration, urban development, agriculture, and mining. Vertical differencing is the subtraction of overlapping gridded elevation data (a.k.a. raster or digital elevation models [DEMs]).
This new vertical differencing Juxtapose slider allows users to visually examine the change between the two hillshade images by dragging the slider. Users can drag the slider to see how the pre-event hillshade image ('compare' dataset) has changed relative to the post-event hillshade image ('reference' data).
Slider image showing change at a quarry near Washington, Indiana between 2013 and 2018. Difference these datasets here.
Slider image showing change at Kīlauea caldera in Hawaii Volcano National Park on the Big Island of Hawaii during eruptions in Summer 2018. Difference these datasets here.
Slider image showing a rockfall fall near Half Dome in Yosemite National Park between summer 2006 and summer 2010. Difference these datasets here.
Learn more about topographic differencing here
How can I access datasets for differencing?