We’ve been working so hard this past year that we forgot to keep our blog up to date! Never fear, we are here now to bring you up to speed on all of the new and shiny features and layers we provide in Worldview.
The most recent and most exciting update: We’ve added a comparison feature! Compare the same imagery from two different dates, compare different imagery for the same date or whatever combination of the above that you like! The comparison feature provides 3 different tools to investigate the imagery – swipe, opacity, and spy. The comparison feature aids in investigating changes between two time periods or quickly comparing different types of imagery on the same date.
Getting Started with the Comparison Tool
Click on “Start Comparison”
The layer list on the left will now show two tabbed layer lists labeled “A” and “B”. Tab A shows the current day, and tab B shows the previous day. The timeline also has “A” and “B” selectors to show which date you are on.
The map now shows the Swipe mode: A vertical line has appeared on the map with the left side labeled “A” and the right side labeled “B”. Click and hold your mouse on the line and move the line left and right to see the changes from one date to another.
You can also change the Compare Mode to Opacity and Spy. Opacity fades from one day’s image to another; spy positions a circular looking glass on the map showing the B state within the circle.
Click on “Exit Comparison” to get out of Comparison mode. You’ll be left on the last tab you had active - maintaining the layers and the date you were last on.
Some interesting comparisons to start you off:
- Agricultural expansion from 2000 - 2018 in Paraguay: https://go.nasa.gov/2NhTIZk
- Fires in California (Spy) - Same day, different imagery: https://go.nasa.gov/2DJGDbR
- Fires in California (Swipe) - Different days, same imagery: https://go.nasa.gov/2QYGaoy
- Snowfall in Lesotho (Swipe): https://go.nasa.gov/2Nj4GO5
- Changes in the Aral Sea (Opacity): https://go.nasa.gov/2RnnTkU
This animated GIF demonstrates Worldview's Comparison feature, using the Opacity mode. It demonstrates changes in the Aral Sea in Kazakhstan and Uzbekistan, between 31 July 2000 (A) and 24 August 2017 (B).
This screenshot demonstrates Worldview's Comparison feature, using the Swipe mode. Snowfall (shown in red using the Corrected Reflectance, Bands 3-6-7 combination) in Lesotho in southern Africa is shown on the left hand side (A) on 11 August 2018, and no snow a few days before on the right hand side (B) on 8 August 2018.
-- Stay tuned for an update on our other new features and abundant new imagery layers!
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