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Posts Tagged: Maggi Kelly

Visualizing the forest

‘Visualizing’ forests from computer and other technological data is common practice in the field of forestry. Forest visualization is used for stand and landscape management and to predict future environmental conditions. Currently, most visualization software packages focus on one forest stand at a time (hundreds of acres), but now we can visualize an entire forest, from ridge top to ridge top. The Sierra Nevada Adaptive Management Project (SNAMP) Spatial Team principle investigators Qinghua Guo, associate professor in the UC Merced School of Engineering; Maggi Kelly, UC Cooperative Extension specialist in the Environmental Science, Policy and Management Department at UC Berkeley; graduate student Jacob Flanagan and undergraduate research assistant Lawrence Lam have created cutting-edge software that allows us to visualize the entire firescape (thousands of acres).

Lidar point cloud
This software uses data collected from a relatively new remote sensing technology called airborne lidar. The word lidar stands for “light detection and ranging” and it works by bouncing light pulses against a target. A portion of that light is reflected back to the airborne sensor and recorded. The time it takes the light to leave and return to the airplane is converted into distance. This measurement, along with position and orientation data from the plane, allows us to calculate the elevation at which the light pulse was reflected, thereby creating a three-dimensional map of the forest vegetation and ground surface. The raw lidar data is seen as a cloud of points from which we can extract meaningful representations. See our lidar FAQ here: http://snamp.cnr.berkeley.edu/documents/251/.

Our new forest visualization software begins by pulling out individual trees from the point cloud. From these individual trees, we extract the tree height and width data. Canopy base height data helps describe the shape of each tree. Then, each individual tree is modeled, and the whole forest is constructed. Visual details such as needles or smooth edges can be added in. This helps to provide a more realistic perspective of the forest than from point clouds alone.  

 

      

      

A forested landscape in the Sierra Nevada (left: a photograph taken with a camera) compared to lidar derived virtual forest (right: simulated scene based on the actual location of trees, tree height, and crown size derived from our lidar data, minus the rocks in the lower left-hand corner)

 

Forest visualization with lidar is useful for helping us understand the complexities in forest structure across the landscape, how the forest recovers from fuels reduction treatments, and how animals with large home ranges might use the forest.

These images, created from lidar data, are still two-dimensional, and thus they lack a sense of depth. To alter that, we have been actively working to bring the created virtual forest into the 3D realm that we are accustomed to seeing in movies or television.  Our proposed 3D system relies on stereoscopic imaging to allow individuals to see in 3D. Stereoscopic imaging refers to an optical illusion created by allowing two offset images to be seen by the viewer’s two eyes, independently. The difference in perspective between the left eye and the right eye causes the brain to process the image with depth, which is how current active stereoscopic images are produced in movies or television. By utilizing the fact that the projected forest is virtual, we can then render two offset images to create a new stereoscopic object. From there, a 3D TV easily overlays the two images on top of the other, alternating an image for the left and then right eye, creating an illusion of 3D and depth for the viewer. Again, these visualizations are not of simulated forests, but of our real Sierra Nevada forest, with every tree in the correct place with respect to the other trees, and seen with the correct height. 

Viewing a virtual scene in 3D. Students Jacob Flanagan and Lawrence Lam at the UC Merced Spatial Lab.

SNAMP links:

 

Posted on Wednesday, June 13, 2012 at 8:43 AM

Want to report SOD? We’ve got an app for that!

When the great outdoors is your research laboratory, gathering data can be a challenge. To get a broader perspective on the extent of damage caused by sudden oak death, a UC Berkeley Cooperative Extension geographer is using crowd sourcing to enhance her research on the disease that has killed over a million of California’s iconic oak trees since 1995.

Maggi Kelly, UC Berkeley Cooperative Extension specialist, started collecting data from community members through her OakMapper website in 2001. Now she has a mobile application for smartphones

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While out in a park or forest, iPhone users can use the new OakMapper mobile app to report sightings of trees killed by Phytophthora ramorum, the plant pathogen that causes SOD. Onsite, participants can note the symptoms they see, such as seeping, bark discoloration, crown discoloration, dead leaves, shoot die-back, fungus, beetle frass and beetle bore holes.

The OakMapper app, created by scientists in the UC Berkeley Geospatial Innovation Facility, uses the phone's built-in GPS to identify the participant’s location when the data is submitted.

They also can describe the environmental setting, such as residential landscape or natural forest.

“Many of the challenging natural resource problems that we face today – like invasive species, fire, climate change – are large in spatial scale and impact diverse public groups,” said Kelly, director of the UC Berkeley Geospatial Innovation Facility. “Addressing these challenges often requires coordinated monitoring, efficient data collection, and increased communication and cooperation between scientists and citizens.

Science can benefit from your powers of observation. We all benefit by becoming informed about problems such as sudden oak death.

If you are like me, a person who sometimes doesn’t recognize coworkers outside the office, you may choose a spectator role. You can use the app to look at the maps to see where SOD is taking down trees.

For more information about OakMapper and its app, visit oakmapper.org. The OakMapper app can be downloaded for free from the iTunes app store.

I’ve heard of two other apps developed at UC to collect natural resources-related data from other scientists and interested members of the public.

You can use UCLA’s What’s Invasive apps to report locations of top invasive plants and animals, which compete with California’s native fauna and flora. By submitting location data and setting up top invasive lists for your area, you can assist scientists monitoring the spread of the destructive invasive plants and animals. Images and brief descriptions in the app help with identification. The apps are free and available for the Android and iPhone.

Soon you will be able to report roadkill sightings on your iPhone. The UC Davis Road Ecology Center has submitted to the iTunes store an iPhone app for reporting roadkill. Until the app becomes available sometime in January, you can report your observations to the California Roadkill Observation System via the Web at http://roadecology.ucdavis.edu/CROS.html.

Another cool app has been developed by the UC Davis Soil Resource Laboratory to deliver information to scientists, growers and gardeners about the properties of their soil. While standing in the field, the user can receive location-based information on a GPS-enabled cell phone. The app is available for free for iPhone and Android OS platforms.

Which science-related apps are you using? You can share them in the comments section or e-mail me at pskanrice@ucdavis.edu.

Posted on Wednesday, December 22, 2010 at 6:33 AM
Tags: apps (2), invasive species (19), Maggi Kelly (7), roadkill (3), soil (18), sudden oak death (33)

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