NOTICE: ltar.nal.usda.gov (this site) will be retired on May 31, 2021.
Please use the new LTAR site at ltar.ars.usda.gov instead. Please also update your bookmarks and references.
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The USDA Agricultural Research Service (ARS) Long-Term Agroecosystem Research (LTAR) network consists of 18 Federal and university agricultural research sites with an average of over 50 years of history. LTAR was established to build the knowledge required for sustainable intensification of agriculture, increasing yields from the current agricultural land base while minimizing or reversing agriculture’s adverse environmental impacts.
This feature lets you compare aerial imagery from different dates.
Select different images/layers from the two dropdown lists at the top of the window. The one chosen on the left will be shown with blue borders. The one on the right with a red border.
Swiper and Spy View are two ways to compare parts of the two images from different years.
Move the slider (dot or bar) in the grey bar at the bottom of the map frame to shift the dividing line across the area of interest. The red and blue progress lines show where the swiper is. The black dividing line shows where comparison is about to happen as you move the sliding bar.
The left (blue) image is displayed. Move the mouse (or your finger) over the image and a red square will replace the image within the square with the right (red) layer. To to change the size of the square, use the up and down button on your keyboard.
To make it easier to tell what part of the display shows the layers selected on the left and right, the list border, image boundaries, spy view, and swiper progress lines are all color coded. Left is always blue, and right is always red.