OpenTopography Blog

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

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Category: Data

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Haiti LiDAR imagery in Google Earth

Posted on Thu, February 11, 2010 by ccrosby in Data • Haiti EQ • News

As discussed in previous blog posts (here and here), LiDAR data have been collected over parts of Haiti following the January 12th earthquake.  The data collected by the Center for Imaging Science at Rochester Institute of Technology (RIT), Kucera International, and ImageCat, Inc., has recently become available via an FTP site maintained by the USGS that is hosting geospatial data acquired in response to the Haiti earthquake.  These data were collected during a campaign between January 21st and the 27th.

In order to make these data easier for all users to access, I downloaded and processed the filtered (bare earth) and unfiltered DEM data into hillshade images (315 degree illumination angle, 1 meter resolution) that can be viewed in Google Earth.  The approach used was similar to what I’ve done for all of the EarthScope LiDAR imagery available via KML (more info is available in this AGU abstract).  The result is roughly ~1.5 GB of hillshade imagery for Haiti hosted on OpenTopography servers that can be browsed seamlessly in Google Earth.  Download the KML file using the button below and open in Google Earth to get started:

NOTES:

• The LiDAR topography data set from which these images were derived was provided by the Center for Imaging Science at Rochester Institute of Technology (RIT) and Kucera International, respectively, under contract to ImageCat, Inc. The Haiti campaign was funded by the World Bank and the Global Facility for Disaster Recovery and Recovery (GFDRR) and have made all data available in the public domain. More information about these data can be found at the RIT Information Products Laboratory for Emergency Response (IPLER) 2010 Haiti Earthquake page.
• 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.
• 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:

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ILMF meeting will highlight Haiti LiDAR

Posted on Tue, February 09, 2010 by ccrosby in Data • Haiti EQ • News

The International LiDAR Mapping Forum (ILMF), a LiDAR industry conference in Denver next month, has just announced in a press release the addition of two presentations related to LiDAR data collected over Haiti (see this post and this post for previous discussion of Haiti LiDAR).

One presentation will be by Ken Hudnut of the USGS, who will discuss the application of post-earthquake LiDAR to evaluation of the ground rupture - or in this case the lack of rupture - associated with the event:

Imagery of the region damaged by the M 7 Haiti earthquake, including high-resolution photography and airborne LiDAR, has revealed a variety of ground failure that resulted from shaking. Surprisingly, the Enriquillo Fault seems to have not ruptured at the ground surface, so the negative result obtained from imagery has significant implications. The USGS issued a statement, based on imagery analysis, that because it is clear that the rupture of the Enriquillo Fault was clearly farther west than Port-au-Prince, and because rupture was buried deep on the fault, there is a significant risk of not only regular aftershocks, but also the threat of a subsequent large event that could occur even closer to Port-au-Prince. The probability of one or more subsequent earthquakes of M 7 or greater increased by about 3% for the 30 days following 21 January 2010. Although this is a low probability, it would be a potentially very high impact event. High-resolution imagery was crucial to this assessment.

Ken is a friend of OpenTopography and was a co-instructor at our Southern California Earthquake Center-sponsored short course on application of LiDAR data to studying active faults this past December.

The second ILMF presentation will be by representatives of Kucera International Inc. who, in collaboration with the Rochester Institute of Technology (RIT) and ImageCat, with funding from the World Bank, performed a high resolution aerial LiDAR and multispectral survey of primary earthquake damaged areas and fault zones:

Kucera’s presentation will review the performance of the aerial survey, the expedited processing and distribution of the aerial data, and potential future refinement and applications of the data.

I’ll be attending the ILMF meeting and I look forward to both of these presentations.  The Haiti earthquake is an important event in terms of being a model for rapid collection of LiDAR following a large earthquake, and I look forward to hearing about the lesson’s learned by both the science users of the data, and the acquisition and processing team.

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A quick look at NGA LiDAR from Haiti

Posted on Wed, January 27, 2010 by ccrosby in Data • Haiti EQ • News

As I pointed out in my last post, there has been a concerted effort by a number of groups to acquire LiDAR data over Haiti in the wake of the January 12th earthquake.  In addition to the Rochester Institute of Technology and Navy groups operating in Haiti, the National Geospatial-Intelligence Agency (NGA) is also collecting data using the ALIRT instrument (described here I think).  Some NGA LiDAR data products are available via the NGA Haiti Earthquake Crisis Relief site.  The LiDAR data products are available in a somewhat haphazard form via the Haiti Filtered LiDAR subpage.  Most of the “data” on this page are actually PDFs and PowerPoint files showing images of the data.  However, there are a few actual data files - one LAS point cloud file and a few DEMs in 32-bit GeoTIFF format.

Since this is the first post-earthquake data I’ve seen available to the public, I pulled a few of these files and have been looking at them.  Below is a screen capture of the LAS file (320,900 pts), which is described as the National Palace, but appears to actually be data from a neighborhood just NW of the Palace:

(UPDATE 02/04/10 - NGA has apparently removed this file so this link is no longer valid) You can download the actual LAS file from NGA here: ALIRT_LIDAR_HTI_NationalPalace_20100120_0218_L3L.las

I gridded the point cloud data above at 25 centimeter resolution and exported it along with the data set footprint to Google Earth.  Shown here:

Download the Google Earth image overlay shown above.

These data are pretty impressive, especially when viewed in tandem with the post-earthquake Google Earth images.  There appears to be misalignment between the lidar and the imagery, but that may have been introduced when I gridded and exported the data to Google Earth (there is no metadata associated with these file, only the coordinate info in the LAS header (UTM z18N)).

The GeoTIFF DEMs produced by NGA and available on the site are also interesting to look at.  Here is a 40 cm DEM overlain in Google Earth:

Download the KMZ file shown above.

Comparison of the LiDAR data above, acquired January 25th, with the Google Earth imagery which was presumably acquired in the days immediately after the earthquake, shows that there is now a set of large tents (field hospital?) in the middle of the athletic fields that isn’t present in the imagery.

It is unclear at this point how much of the data that NGA is collecting over Haiti will be made available to the public.  I hope that they intend release the full data set in an easy to access manner (e.g. all the DEMs, the las files, or both).  OpenTopography has been in contact with NGA and we’ve offered to host whatever portion of this data set they are willing to share with the scientific community and the general public.  Stay tuned.

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Haiti LiDAR

Posted on Fri, January 22, 2010 by ccrosby in Data • Haiti EQ • News

Recent reports indicate that there is LiDAR data being collected by a number of groups over Haiti in the wake of the 12 January magnitude 7.0 earthquake.  These data will potentially be powerful for earthquake relief workers and the scientific community, and should be an important geospatial resource in the recovery and rebuilding of Haiti.

This news article describes the work being done by the Naval Meteorology and Oceanography Command out of Stennis Space Center in Mississippi to acquire LiDAR around Haiti.  These collections are apparently hydrographic surveys of ports and other areas in Haiti using the CHARTS (Compact Hydrographic Airborne Rapid Total Survey) system.  More information about the CHARTS system and the National Coastal Mapping program is available here.

Today, a press release entitled, Rochester Institute of Technology Captures Haiti Disaster With High-Tech Imaging System; World Bank Funds Five-Day Mission, was issued that describes the data collection being conducted by a team out of RIT who are acquiring LiDAR, high-resolution color imagery, and thermal infrared data using a platform called WASP (Wildfire Airborne Sensor Program) designed to detect wildfires.  The press release provides quite a bit of information about the acquisition, data products, and logistics of the collection.  Specifically on the topic of the LiDAR data, the press release states:

The LIDAR capability detects and measures collapsed buildings and standing structures damaged by the earthquake. At the request of the U.S. Geological Survey, Faulring is using LIDAR to map the fault line to estimate how much the earth moved. This information is critical to refinement of earthquake-risk prediction models.

Application of these data to investigations of co-seismic ground rupture is logical and given the tropical vegetation in Haiti I would expect that the data may prove quite useful for locating and documenting surface rupture associated with the earthquake.  This is also a potentially interesting test case for application of LiDAR to post-earthquake scientific investigations, but is not the first time that airborne LiDAR has been collected immediately following an earthquake.  That honor goes to the LiDAR data collected following the 16 October 1999 Hector Mine, CA Earthquake and available for download here.

My understanding is that the RIT WASP data will made publicly available as soon as it has been processed.  At this time I don’t have specific information on how they intend to distribute the data products, but we’ve offered OpenTopography as a potential access point for the data if there is a need to host it someplace.  When we know more about how to access these data we’ll provide an update.

Finally, I understand that the scientific community has deployed at least one terrestrial laser scanner (TLS) instrument to Haiti for post-earthquake investigations.

UPDATE (January 24): Wired Science has a nice article with more information and preliminary images of the RIT LiDAR data discussed above:  New 3-D Aerial Images of Haiti Will Aid Recovery and Research

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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.

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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:

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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.

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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.

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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:

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Comparison of ASTER GDEM to SRTM

Posted on Mon, August 03, 2009 by ccrosby in Data

The recently released ASTER Global Digital Elevation Map (GDEM) from NASA and Japan’s METI has been widely publicized on geospatial data blogs, email lists and in the mainstream media.  At 30 meter resolution, these data promise relatively high-resolution DEM coverage for most of the globe (coverage falls between 83N and 83S latitudes).  These data can be accessed either via NASA’s EOS archive or Japan’s Ground Data System

OpenTopography team member Ramon Arrowsmith has a preliminary comparison of the ASTER GDEM data with 90 m Shuttle Radar Topography Mission (SRTM) data on his blog.  Ramon notes that due to various artifacts and high-frequency noise, the GDEM data may not be as impressive as one would hope relative to the SRTM data.

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