OpenTopography Blog

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

---

Geomorphology: Understanding earth surface processes from remotely sensed digital terrain models

Posted on Tue, January 19, 2010 by ccrosby in Publications • Resources

I’m a bit late on this, but the December 1, 2009, Geomorphology special volume: Understanding earth surface processes from remotely sensed digital terrain models, edited by Paolo Tarolli, J Ramon Arrowsmith and Enrique Vivoni is an excellent collection of papers related to the study of geomorphic processes with terrestrial laser scanning, airborne lidar, and satellite-based topographic remote sensing. 

Ramon kindly provides a link to the volume’s preface for those who are interested.

---

AAPG Rocky Mountain Section Meeting Lidar Session

Posted on Mon, January 11, 2010 by ccrosby in Meetings

An interesting Lidar-oriented session at the AAPG Rocky Mountain Section Meeting in Durango Colorado June 13-16, 2010.  Announcement via the GEOMOD-LIDAR-L and ASU LIDAR listservs:

Greetings all,

The AAPG Rocky Mountain Section Meeting will be held in Durango Colorado June 13-16, 2010. In addition to a broad range of technical sessions, the meeting features a session “Multi-scale Observations and the Application of Remoting Sensing and Lidar to Rocky Mountain Petroleum Exploration”.  This technical session is being co-chaired by Tim F. Wawrzyniec (tfw@unm.edu) and Gary Weissmann (weissman@unm.edu).

We invite contributions from all geologic and geophysics disciplines centered around the principle theme of field-based studies that are combined with digital geospatial characterization as applied to geologic problems.  Although lidar technology is of specific interest, we encourage the submission of talks that include studies where seismic, ground-pentrating radar, or other remote sensing approaches that have been deployed to build imagery to enhance our understanding of geologic process.

If you are interested in contributing, please contact either of the technical chairs if you have any questions.  Otherwise, follow either of the following links:

http://www.fourcornersgeologicalsociety.org/meeting_2010/index.asp

or

http://www.aapg.org/meetings/rms/

The deadline for submission is February 1, 2010.

On behalf of the technical committee thanks for your attention and hopefully we will see you in Durango!

Cheers
Tim & Gary

---

LAS Conversion Tools:  LAStools and LASUtility

Posted on Wed, January 06, 2010 by ccrosby in Software

The ASPRS LAS format has become the standard for delivery of lidar point cloud data.  However, because LAS is a binary format, a reader of some kind is necessary to ingest the data, visualize it, or perform additional analysis.  Many of the major GIS software packages now support LAS (e.g. ArcGIS) and all of the commercial lidar specific software read and write LAS data.  Some users however lack access to software that will read the LAS format and thus would like to view lidar point cloud data in ascii format.  In these situations I typically recommend the excellent and free LAStools (or LAStools’ Open Source Geospatial foundation relative libLAS), a package of utilities for reading and writing LAS files.  The downside to LAStools is that the utilities are command line-based, which tends to scare away some users.  If you are interested in LAStools, take a look at the short LAStools tutorial that we’ve used in past OpenTopography short courses.

Today I learned about an alternative to LAStools, called LASUtility from an Indian company called GeoKno.  Like LAStools, LASUtility offers the ability to view LAS headers, convert LAS data to ascii and vice versa, merge or subset LAS files, etc.  However, LASUtility is a Java application that includes a graphical user interface (gui) to the commands unlike LAStools.  The fact that it is a Java app also means that in theory LASUtility will run on platforms other than windows (the readme says Windows, Linnux, Solaris), but the download only includes a Windows executable.  LASUtility is a free download, and a free 5 day license is available (read the “Readme.txt” file in the downloaded directory for info on obtaining a license).  It is unclear to me if longer term licenses are free or require payment.

A quick test drive of LASUtility using a sample LAS file (~220 MB .las) indicated that it generally works as promised but is quite a bit slower than the command line LAStools.  There also seems to to be less control over how file conversions are done - for example, the “LAS to XYZ” and “LAS to text” commands don’t allow you to define the delimiter in the ascii file (files are written as tab delimited).  On the plus side, LASUtility provides a simple (but slow) 3D viewer for the LAS file and claims to offer graphical sub-setting of files (allowing users to draw a bounding box), but I couldn’t get the interface to launch.

LASUtility:

If you are working with lidar point cloud data in LAS format, LAStools is a set of utilities that should definitely be part of your tool kit.  If you are command line averse, LASUtility may also be worth a look.

---

Pardon Our Dust

Posted on Fri, November 20, 2009 by ccrosby in OpenTopography Updates

OpenTopography is taking advantage of the expected lower than normal visitor traffic over the upcoming holiday week to make some site updates.  We will be rolling out a new logo, site skin, and modified navigation among other things.  We apologize in advance if you visit over the next week or so and things seem a little off - rest assured that the site should be back to normal by the first week in December.  Here’s a sneak peek at what the site will look like when we are done:

Also in the coming weeks, OpenTopography plans to release quite a bit more data and to roll out some new features.  Stay tuned…

---

USGS LiDAR Funding Opportunity

Posted on Wed, November 04, 2009 by ccrosby in Data • News

Last week the USGS released its much anticipated LiDAR and Orthoimagery RFP.  The ARRA (American Recovery and Reinvestment Act of 2009) funded RFP will award 15 grants of up to $500,000 each for the “collection and processing of high resolution elevation data and orthoimagery”.  The grant is only open to institutions of higher education and state, local and Indian tribal governments.  Federal agencies and the private sector are not eligible.

Priorities for the grant are relatively specific with a focus on coastal portions of the country: ”Priorities for the program include collecting elevation data over those coastal areas of United States most susceptible to storm and hurricane flooding, earthquake damage, and coastal erosion”.  All data collected by organizations funded via this grant will ultimately be ingested into the USGS National Elevation Dataset (NED) to expand the extent of available 1/9 arc second (roughly 3 meter) topography data.  The announcement also specifies that all raw LiDAR point cloud data will be added to the archive maintained by the USGS Center for LIDAR Information Coordination and Knowledge (CLICK).  The announcement includes the following map, which shows the regions of the country that are deemed highest priority for ARRA topography funds.  The map also shows the extent and status of 1/9 arc second topography in NED - most of which is data derived from state, local and federal LiDAR data collections - and may therefore be interesting for folks curious about where LiDAR data may be available in their region or area of research.  Regional, zoomed views, of the map below can be downloaded as a supplement to the grant announcement.

Although this grant is an exciting opportunity to acquire a significant amount of new LiDAR data, there has been significant debate about the quality of the data specified by the RFP.  The grant announcement specifies “high resolution (1 point per square meter (ppsm)) lidar”, which is significantly lower resolution than the 6-8+ shots per square meter data that is being delivered by projects such as the EarthScope (data hosted here on OpenTopography), and the Oregon and Puget Sound LiDAR Consortia.  Therefore, there is concern that these USGS-funded data will be of less utility to Earth science researchers, especially in areas of steep terrain and dense vegetation.

---

Oregon LiDAR Viewer

Posted on Tue, October 06, 2009 by ccrosby in Data • News

A few weeks ago I wrote a post on the release of Oregon’s LiDAR Data and Map Series.  Now, Ian Madin at DOGAMI reports that they have released a new LiDAR data viewer to allow the general public to easily view the data and for GIS users to preview the data before purchasing it.

The new Orgeon LiDAR viewer can be accessed here:
http://www.oregongeology.org/sub/lidardataviewer/index.htm

The viewer allows users to see hillshade and slopeshade images and contours derived from lidar collected by DOGAMI with Oregon Lidar Consortium funding.  The viewer currently has data from three surveys, and more will be added as new data is finalized.  The intent of the viewer is to allow the general public to see the data without the need for GIS software, and to allow GIS users to preview the data that they may then obtain through our LDG publication series.

Here is a quick screen capture of the viewer:

---

Request for NCALM Seed Proposals from Graduate Students

Posted on Wed, September 30, 2009 by ccrosby in Data • News

NCALM‘s annual announcement for their seed proposals went out yesterday via various email listservs.  This an an excellent opportunity for graduate students to obtain free LiDAR data for an area related to their research.

The National Center for Airborne Laser Mapping (NCALM) invites graduate students who are interested in research grade airborne laser swath mapping (ALSM or lidar) data to make use of the center’s facilities through the Seed projects program. This year the program will support 10 seed projects covering an area no more than 40 sq. km. each. These projects are intended to provide data to graduate students early in their research program, so that availability of such data may seed further research and support, building upon discoveries made possible by ALSM technology.

The proposals can be submitted electronically by visiting the center’s website http://www.ncalm.org. The submission deadline is November 16, 2009.

---

An Update on Southern California LiDAR Coverage of Active Faults

Posted on Tue, September 15, 2009 by ccrosby in Data • OpenTopography Updates

OpenTopography has released yet another round of GeoEarthScope LiDAR data for active faults in southern California.  The most recent release includes the Elsinore fault, the Burro Flats segment of San Andreas fault, and the Crater Mountain portion of the Owens Valley, adding to the existing SoCal fault coverage that includes the Garlock, the San Andreas and San Jacinto and a number of faults in the Eastern California Shear Zone in the Mojave.  At the Southern California Earthquake Center Annual Meeting in Palm Springs this week, I presented a poster that provides an update on the status of LiDAR coverage for active faults in southern California available via OpenTopography.  The image below comes from my poster and nicely summarizes the southern California LiDAR data currently available via OpenTopography as well as what will be available in the near future.

As you can see, if the area is shown in yellow, those data were collected by GeoEarthScope and are currently available via OpenTopography.  Likewise, areas outlined in orange are also available via OpenTopography, but these data were collected by campaigns other than GeoEarthScope (e.g. the B4 and the ECSZ projects). Finally, areas shown in green are GeoEarthScope data that have not been delivered to OpenTopography for distribution to the community but that we expect to arrive in the next few months.  As always, you can use the data overview page in OpenTopography to see what data is available in the system.

---

LiDAR-Specific Sessions at Fall AGU Meeting

Posted on Fri, August 28, 2009 by ccrosby in Meetings

There will be two sessions at the 2009 Fall American Geophysical Union (AGU) Meeting in San Francisco (December 14-18, 2009) specifically targeted at Earth science applications of LiDAR.

One session is focused on terrestrial LiDAR (TLS):

G17: Ground Based Geodetic Techniques and Science Applications
Conveners:  Gerald W Bawden- US Geological Survey, Benjamin Brooks - University of Hawaii, David Phillips - UNAVCO

Ground-based geodesy is a rapidly expanding and evolving technology and because of their portability, relative ease of use, long acquisition ranges, and sub-cm spatial resolution, tools such as terrestrial laser scanners (TLS) and/or ground-based radars (GBR) promise to expand our detailed understanding of the fundamental processes that drive a broad range of spatial (3D) and temporal (4D) science applications. This special session invites contributions that discuss both the technical aspects of the technology and process-based geoscience studies using ground-based geodetic tools such as, but not limited to, TLS and GBR. What are the strengths, weaknesses, and limitations of the technologies? How is the technology being used to address static and dynamic scientific problems? We envision contributions from many disciplines such as natural hazards, geomorphology, structural geology, glaciology, hydrology, snow science, biological science, tectonic, and volcanology.

while the other emphasizes airborne data:

G13: Airborne Geodetic Imaging: Advances in Instrumentation and Methods
Conveners:  William Eugene Carter - University of Florida, Ramesh L Shrestha - University of Florida, Mahta Moghaddam - University of Michigan

Modern airborne geodetic imaging sensors, including airborne laser swath mapping (ALSM), interferometric synthetic aperture radar (InSAR, UAV SAR), multi-band digital photography, and hyperspectral imaging make it possible to collect high resolution (few meters down to sub-meter scales) topographic data over areas of hundreds to thousands of square kilometers, in time periods of hours. The resolution of these geodetic images is sufficient for developing and testing theories pertaining to land surface processes, and are increasingly being used for such other applications as surface-water hydrology, bathymetric mapping, landscape ecology, mapping of wildlife habitats, and forestry research and management. The focus of this session will be on recent advances in geodetic imaging technologies and methods, and more specifically on advances in the state-of-the-art of the instrumentation, operating procedures, processing, and filtering of observations to achieve the highest resolution and accuracy. Also of interest will be presentations focusing on possible improvements to the information content that might be achieved by combining observations from different geodetic imaging sensors (particularly of different resolutions), and combining geodetic imaging data with other types of observations. Presentations reporting scientific results obtained using geodetic images will be welcome, but the emphasis should be on the geodetic aspects of the research as opposed to discoveries more appropriate for presentation in sessions organized under other disciplines.

The AGU abstract submission deadline is September 3rd, 2009, 23:59 EST

---

Oregon Releases LiDAR Data and Map Series

Posted on Wed, August 26, 2009 by ccrosby in Data • News

This week the Oregon Department of Geology and Mineral Industries (DOGAMI) released a new digital map series and a new digital data series featuring LiDAR data collected in the Portland Metro area by the Oregon Lidar Consortium.  Details about the release are available in a press release [PDF] and on their new LiDAR Publications page.

The Lidar Imagery Series (LIS) publications are PDF format maps showing bare earth and first return ("highest hit” in DOGAMI parlance) surfaces.  20 ft contours are shown on the bare earth images while the “highest hit” surface has the vegetation colored by height.  Both maps are quite attractive and appear positioned to replace the iconic USGS 7.5 minute quad maps.  Each LIS quad map costs $30 and can be ordered on CD ROM.

Although the LIS maps are pretty, more exciting is the actual data that was used to generate the maps.  DOGAMI is releasing these data as Lidar Data Quadrangles (LDQ) where each quad includes bare earth, first return and intensity images of the data.  Unfortunately, these data are not available for direct download and instead must be ordered on DVD at a rate of $200 per 7.5 quad.  The good news is that DOGAMI has made the all point cloud data available for free via the NOAA Topographic Change Mapping site and therefore it is possible to access custom gridded products in addition to the point cloud data.

UPDATE (08/27/09 @ 12:40 PM):
I ran a few quick jobs on the NOAA Topographic Change site to extract some of the new DOGAMI LiDAR data.  Below is point cloud data for the Willamette River through downtown Portland, OR.  The bridge in the center of the image is the Burnside:

It appears there may be an intensity calibration issue with these data based on the fact that the intensity of the points in the distance in the image are significantly darker than those in the foreground - the intensity difference appears to be along a tile edge - here is another look :

UPDATE: Ian Madin at DOGAMI reports that this intensity difference is due to the fact that there were two different sensors in use during the survey: ”Some of our data was flown with an Optech and Leica sensor, and the intensity images from those overlap areas often show significant differences.  The Optech also produced noisier data which shows up in a slopeshade map of the same area”


2 meter first return DEM of the same data that I also generated via the NOAA site:

---

Page 2 of 5 pages  <  1 2 3 4 >  Last »

RSS