OpenTopography Blog

Information and discussion related to high-resolution LiDAR topography for the Earth sciences

---

Posts from May 2010

---

Terrestrial Laser Scanning: Applications in Geology and Geomorphology session at GSA 2010

Posted on Sun, May 23, 2010 by Chris Crosby in Meetings • TLS

TLS session at the 2010 Geological Society of America Meeting in Denver, CO announced.  Via the GEOMORPHLIST:

Dear Colleague-

With apologies for cross-posting, I encourage you to submit abstracts for Session T.125 Terrestrial Laser Scanning: Applications in Geology and Geomorphology at GSA 2010 in Denver, Colorado.  This session is co-sponsored by the GSA Engineering Geology Division and the GSA Quaternary Geology and Geomorphology Division.

Contributions describing the applications of this technology, as well as discussions of critical issues associated with the implementation of TLS to geomorphic and geologic studies are encouraged.

Feel free to contact me if you have any questions.

Thanks,

Dennis M. Staley
U.S. Geological Survey
1711 Illinois St
Golden, CO 80401
303.273.8568

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Session Description:

The characterization of surface features at multiple spatial scales is fundamental to understanding the process-form interactions and to the progression of geomorphic and geologic research.  Terrestrial laser scanning (TLS, commonly referred to as terrestrial LiDAR) permits the development of topographic data at unprecedented spatial and temporal resolutions over large areas. TLS data in the form of point clouds and/or digital terrain models are used to assess topographic boundary conditions, enhance geomorphological mapping by identifying spatial patterns and morphometric changes in landforms at various spatial scales, quantify rates of sediment transport through morphological DTM of differences approaches, and serve as benchmark datasets to test numerical and physical models of surface processes.  Repeat TLS surveys also permit the detection of fine scale changes in topography associated with geomorphic processes.

Advancing our understanding of geomorphic processes by incorporating TLS methodology presents new challenges: evaluation of scalar variability and dependencies in process-form relationships; linking process mechanics to high resolution topographic data, and data storage and transfer issues are also important considerations in TLS analytics.  While similar topics have been previously addressed at professional conferences (e.g. the LiDAR oral and poster sessions at the previous GSA meeting), these sessions have largely focused upon airborne LiDAR applications. Very little discussion has centered on TLS applications.  The growing popularity of TLS use in the geosciences necessitates a session devoted to the development of TLS methodology and data analysis in geology and geomorphology.  This session seeks to bring together researchers using TLS to identify and discuss critical issues concerning the application of TLS in the geosciences, as well as highlight cutting edge research that utilizes this methodology to further our understanding of the processes that sculpt the surface of the Earth.

---

LiDAR data for N. Baja, Mexico in Google Earth: pre-M 7.2 El Mayor - Cucapah earthquake

Posted on Tue, May 04, 2010 by Chris Crosby in 2010 Baja EQ • Data • Google Earth

Thanks to a close collaboration with OpenTopography colleague Alejandro Hinojosa at CICESE in Ensenada, Mexico, we have obtained 5 meter resolution LiDAR topography data for the epicentral region of the Sunday, April 4th 2010 magnitude 7.2 El Mayor - Cucapah earthquake in northern Baja, Mexico.  These data, which cover an area of over 2,000 square kilometers southwest of Mexicali, were acquired in 2006 by the Instituto Nacional de Estadística y Geografía (INEGI), a Mexican government agency.  We’ve been told that these data were collected from an elevation of 6000 m with GSD of 10 to 12 meters. 

As I’ve done for the EarthScope LiDAR hosted by OpenTopography as well as the data collected following the January Haiti Earthquake, I’ve generated hillshade and slopeshde imagery from the DEM data and produced a network linked Google Earth KMZ file that can be used to access the imagery.  Download the KMZ file using the button below and open in Google Earth to get started:

At the moment, we have not obtained permission from the INEGI to release the actual DEM data (and we do not have the point cloud data), but we hope that the derived imagery accessed via Google Earth will be helpful for researchers currently investigating ground rupture and other phenomena associated with last month’s earthquake.  To assist groups working in the field who won’t have network access to connect to the imagery stored on OpenTopography servers, KMZs with the imagery stored locally can be downloaded below:

• KMZ with 315 degree imagery
• KMZ with 45 degree imagery
• KMZ with slopeshade imagery

We anticipate that higher-resolution LiDAR topography will be collected along the ground rupture in the next few weeks.  Clearly these pre-event data, although lower resolution than forthcoming data in the region, present an exciting opportunity for comparing pre- and post-event data to calculate near-field deformation along the rupture.  We’re optimistic that we’ll be able to obtain permission to distribute both the DEM and point cloud INEGI data in the future so that they can be used for these types of analysis.

NOTES:

• The LiDAR topography data set from which these images were derived was acquired by INEGI and kindly provided to OpenTopography by Alejandro Hinojosa at CICESE.  Citation for the LiDAR topography data is: ”INEGI 2006, Modelo digital de elevación de alta resolución Lidar, Tipo TERRENO”.
• The extent of the LiDAR data is shown by the cyan colored outlines.  The images will load once the user has zoomed into an area of interest.  The imagery becomes progressively higher resolution as you zoom in.
• All of the imagery is accessed via “Network Link” to servers in San Diego, thus a strong and consistent internet connection is required.  Alternatively, you can download the individual KMZ files above where the imagery is stored locally, removing the need for a network connection.  Note however that access to the default imagery and map layers in Google Earth requires a connection.
• The transparency of the LiDAR hillshades can be adjusted using the slider bar at the bottom of the PLACES menu in the left hand navigation bar.

EXAMPLES:

---

New Point Cloud Processing and Custom DEM Video Tutorial

Posted on Mon, May 03, 2010 by Chris Crosby in Education • OpenTopography Updates

Thanks to the ASU Capstone team - a group of senior undergraduate School of Computing and Informatics students at Arizona State supervised by OpenTopography Co-I Ramon Arrowsmith - we now have a very nice video tutorial on how to use OpenTopography to download and process LiDAR point cloud data to digital elevation models:

This is the first of what we hope will be a series of instructional videos that will appear on the OpenTopography Tutorials page and the OpenTopography YouTube channel.  Stay tuned for more soon.

---

Page 1 of 1 pages

RSS