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Sunday, August 20, 2017

LIDAR, Connecticut Forests, and Iowa Marching Bear Effigy Mounds

       Dr. Katharine Johnson from the University of Connecticut (UConn) focuses on uncovering  
hidden remnants of the past using LIDAR imaging. The name LIDAR, sometimes considered an acronym of Light Detection And Ranging (sometimes Light Imaging, Detection, And Ranging), was originally a portmanteau of light and radar. Johnson and her colleagues have been piercing dense forest cover to uncover historic sites in New England (as seen here in Plainfield, Connecticut).

      

     Many of the tree-covered landscapes of modern New England were not always so green. In the 17th century, the region was the site of widespread deforestation, as European colonists built farms and homesteads. Between 60 to 80 percent of the land was cleared for fields, pastures, and orchards; these were surrounded with stone walls, houses, outbuildings, and roads.



      The natural-color photograph above was shot during an aerial survey in 2012. The monochromatic light detection and ranging (LIDAR) image, captured in 2010, shows the same area with greater contrast and reveals features on the ground. 




      LIDAR instruments send out rapid pulses of laser light that reflect off of solid surfaces (such as tree limbs or the ground). A receiver detects the photons that bounce back to the instrument, parsing out subtle variations in land elevation and allowing researchers to distinguish bumps and surfaces on the terrain.




      LIDAR has been used by archaeologists in other landscapes, perhaps most famously in Belize, where researchers have used it to uncover ancient Maya sites. The startling Marching Bear Effigy Mounds in northeastern Iowa were highlighted with LIDAR as well.

        


     “You can see patterns people made as they were dividing the landscape and farming,” said Johnson. LIDAR imaging helped them uncover traces of stone walls, dams, abandoned roads, building foundations, farm structures, and relict charcoal hearths—all of which have been slowly hidden over the past two centuries as the forest reclaimed the land.




 “The biggest surprise was being able to see the extent to which historic land use had impacted the landscape, which is not something that is readily visible in high-resolution aerial photos.”



Happy 24th birthday to Zoë today! Here she is celebrating with fellow Peace Corps volunteers in Ethiopia.



Have you used LIDAR?
Steph

Eclipse photos. Moonshadow. Moonshadow. . .How was your solar eclipse experience?








Eclipse at the Great Sand Dunes, Colorado--whoa!



17 comments:

  1. Happy birthday, Zoë!

    I'm a little unclear on how lidar can show subtle elevation changes in terrain that's heavily forested, when direct sunlight doesn't penetrate to the forest floor.

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    1. I'm a little unclear as well, jan. Here's a recent article (6/17) that explains some of the newer techniques within LIDAR, and the way it penetrates to the forest floor.

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  2. West coast "goes first" for solar eclipse viewing--yeehaw! ;-)

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  3. I added a couple of solar eclipse images. How was your eclipse experience?

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    Replies
    1. I made a pinhole projector/viewer with an empty cereal box and a little aluminum foil, which gave me a fair image of our 70% eclipse. Someone in the office had a pair of eclipse specs, which worked better. But really, it's the rarity of the event that was notable, not the spectacle.

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    2. ;-)

      Yeah, the solar specs worked great. It was fun to hang with the kindergartners and watch their reactions.

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  4. Replies
    1. Those are great, jan. Thanks.

      I find it weird that the Wash Post chose to order their favorite eclipse photos from east to west.

      The "Wyoming" image is my favorite.

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    2. Thanks for those, do these things make you want to break out in song?

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    3. eco, the Moonshadow song ran through my head during the entire few hours.

      I have Portland friends who lived on Moonshadow Court. I've always thought it was a cool name.

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    4. I was also thinking of this song at the very end of the eclipse.

      When the Japanese poet Ishikawa Jozan built his retreat, called Shisen-do, in Kyoto he included a Tower for Whistling at the Moon, an ever evocative image.

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    5. The Baily's beads effect is cool. Glad you were treated to diamonds!

      Lovely spot to commune with the moon. . .

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  5. Oooh, I just added an image of the eclipse at the Great Sand Dunes of Colorado. Be still my heart!

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  6. New post on "Trig Warning: 3700-Year-Old Babylonian Tablet" is now up. Enjoy!

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