Archives for January 2016

Visualization of Tree Crown using Airborne Laser Scanner Data in Tropical Forest

Download Free version on : http://appliedimagery.com/

The term “landslide” describes a wide variety of processes that result in the downward and outward movement of slope-forming materials including rock, soil, artificial fill, or a combination of these. The materials may move by falling, toppling, sliding, spreading, or flowing. Figure 1 shows a graphic illustration of a landslide, with the commonly accepted terminology describing its features.

The various types of landslides can be differentiated by the kinds of material involved and the mode of movement. A classification system based on these parameters is shown in figure 2. Other classification systems incorporate additional variables, such as the rate of movement and the water, air, or ice content of the landslide material.

Figure 1: An idealized slump-earth flow showing commonly used nomenclature for labeling the parts of a landslide

Figure 2: Types of landslides. Abbreviated version of Varnes’ classification of slope movements (Varnes, 1978).

Read more on :  (http://pubs.usgs.gov/fs/2004/3072/fs-2004-3072.html)

The Oso landslide in Washington state is the subject of research to better understand the likelihood of this kind of event happening again.

A team of scientists from the University of Washington has published a new study concluding that the deadliest landslide in US history, which killed more than 40 people in Oso, Washington, was not a fluke. In fact, they estimated that over the past 2,000 years, the same stretch of valley has been slammed by a major slide every 140 years, on average.

Using lidar images, the scientists zoomed in on old slides and quantified how rough their surfaces were. Then they compared slides of known ages to slides of unknown ages to come up with an approximate scale.

According to UW Today post, LaHusen, a University of Washington doctoral student and lead author on the paper published online by the journal Geology, said “This is the first time this calibrated surface dating method has been used for landslide chronologies, and it seems to work really well.”

– See more at: http://blog.lidarnews.com/#sthash.8RNgQCJq.dpuf

Let’s kick off the new year (2016) with a heads up about a portable scanner that I have not heard of. It’s the EinScan-S from Shining 3D and it claims to “scan both people and objects in high resolution, down to the smallest detail, thanks to its interchangeable settings that allow for high-accuracy scanning of both large and small objects.”

They report, “If positive reviews from award-winning visual effects artists aren’t enough, the EinScan-S also recently passed the vigorous iMakr test. iMakr, the retailer of all things 3D, is famous for its high standards, putting every product through rigorous and extensive tests before accepting them into its stock. After about a month and a half of assessment, iMakr accepted the EinScan-S, which will be sold from the retailer’s online store as well as its two brick-and-mortar locations in London and New York.

– See more at: http://blog.lidarnews.com/#sthash.8RNgQCJq.dpuf

This is an excellent presentation on the future of lidar data acquisition and processing by Dr. Qassim Abdullah who works for Woolpert, Inc. He discusses all of the major topics including single photon counting and Geiger mode as well as full waveform and flash. Qassim also contrasts the benefits and limitations of each system. He also looks into the future to predict what the state of the art might be in five years.

This is an important reference for all topics related to airborne lidar data collection.

– See more at: http://blog.lidarnews.com/#sthash.7Q0CcsbM.dpuf

The hotter the water temperature in a river the less oxygen that is carried. This can cause problems for certain fish species such as rainbow trout. The slower the river is flowing the more it heats up.

Idaho Power hired Quantum Spatial to map the Snake River using bathymetric lidar. In order to model the velocity of the river the contours of the river bottom must be known.

On of the challenges with topo bathy is the depth of penetration of the laser usually as a result of turbidity of the water. They really won’t know until the data is processed whether they were able to reach the bottom.

– See more at: http://blog.lidarnews.com/#sthash.7Q0CcsbM.dpuf