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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LiDAR Beginning to Appear in Google Maps Terrain Layer

Posted on Fri, July 30, 2010 by C. Crosby in Data • Google Earth • Google Maps

One of my favorite features in Google Maps is the terrain layer, which provides a shaded relief (aka hillshade) view of the topography derived from a digital elevation model.  Google has done a nice job generating a visually pleasing terrain layer, and we use it for all of our Google Maps-based interfaces in OpenTopography.  Google appears to use a range of digital elevation model data sources to derive the terrain layer.  Throughout the US, it appears that the terrain layer comes from either 10 or 30 m (1/3 arc-second & 1 arc-second respectively) DEMs from the USGS National Elevation Dataset (NED).  Globally the terrain data appear to be derived from either Shuttle Radar Topography Mission (SRTM) data or something like the NOAA Global Land One-km Base Elevation Project (GLOBE) dataset.  Recently however, I’ve begun to notice higher resolution data in the Google Maps terrain layer.  These higher-resolution data are localized, and are patched into the terrain layer among the standard 10 and 30 m derived images, but they are impressive when you find them.  Based on the location of these patches of high-resolution terrain, and their appearance, it is pretty easy to deduce that Google is now incorporating bare earth LiDAR digital elevation models into the Google Maps terrain layer.

Thus far, I’ve noticed high-resolution data in downtown Portland, OR, the greater Los Angeles area, and Mount Saint Helens in Washington.  There may be other examples of LiDAR-derived terrain in Google Maps since I haven’t searched very hard.  If you are aware of other areas leave a comment.

Below are a few sites in Google Maps where you can clearly see the high-resolution data.

Downtown Portland, OR.  Data are sourced from the Oregon LiDAR Consortium managed by the Oregon Department of Geology and Mineral Industries (DOGAMI).  Note obvious building foundations, hillslope modifications, etc.:

View Larger Map

Edge of LiDAR near Washington Park in Portland - bare earth LiDAR on the east side, 10 m (?) data on the west:

View Larger Map

LiDAR bare earth data near Beverly Hills, CA.  I’m not sure of the origin of these data - does anyone know if the original LiDAR point cloud and DEM data are publicly available?:

View Larger Map

Obvious seam between LiDAR grids and lower resolution terrain data north of Yorba Linda, CA:

View Larger Map

Finally, the very impressive Mount Saint Helens data.  Presumably these are the data collected by NASA in partnership with USGS in 2003-2004 during a period of significant volcanic activity:

View Larger Map

It is really nice to see these high-resolution terrain datasets making it into such a common and easily accessible platform like Google Maps.  OpenTopography provides network-linked KMZ files to deliver LiDAR derived imagery data to Google Earth so that they are available to non-expert users, and direct incorporation of these data into the Google Maps terrain layer takes the accessibility of these data one step further.  As the number of public domain LiDAR data collections increases, I’d expect that we’ll see more examples of LiDAR appearing in maps and online visualizations accessible to the general public. 

An interesting, and logical follow on question to LiDAR in Google Maps, is when will Google will tackle the integration of high-resolution terrain data into the topographic mesh in Google Earth?  For the Earth science community, 1 meter terrain data in Google earth would be revolutionary.

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Recap: Accessing Haiti Earthquake LiDAR Data

Posted on Mon, June 21, 2010 by C. Crosby in 2010 Haiti EQ • Data

Following the January 12th, 2010 Haiti earthquake I wrote a number of blog posts related to the post-earthquake LiDAR data that were collected by the Center for Imaging Science at Rochester Institute of Technology (RIT), Kucera International, and ImageCat, Inc (with funding from the World Bank), and the National Geospatial Intelligence Agency (NGA).  As a result of these posts OpenTopography gets quite a bit of traffic from people looking for information about these data.  Although discussed in previous posts, we still get emails asking how to access the data.

Given that there appears to be some confusion, here is a quick summary of how to access the publicly available Haiti lidar data products.  If you are aware of other pathways to the data leave a comment and I’ll update the list.

Point cloud data:

The World Bank funded data are available from the RIT Information Products Laboratory for Emergency Response (IPLER) Haiti earthquake page.  Available products include classified point clouds in LAS format and first return (SEM) and bare earth (DEM) terrain models in GeoTIFF formats.  From the IPLER Haiti page:

Data can be DOWNLOADED: Anonymous FTP (not an SFTP) using thor.cis.rit.edu OR the WASP HTTP Site

UPDATE August 5th, 2010: OpenTopography is now hosting the full World Bank - ImageCat Inc. - RIT Haiti Earthquake LiDAR point cloud dataset.  You can access these data HERE.


Gridded Products (DEMs):

First return (SEM) and bare earth (DEM) terrain models in GeoTIFF formats (derived from the LAS point cloud data) are available via the IPLER Haiti FTP and HTTP sites listed above, or from an FTP site hosted by the USGS that was deployed to host earthquake-related data: http://edcftp.cr.usgs.gov/pub/data/disaster/201001_Earthquake_Haiti/

Google Earth Image Overlays:

Using the gridded World Bank LiDAR data downloaded from the USGS FTP site above, I generated a cache of hillshade imagery and a network linked KML file to access these images in Google Earth.  Download of the KML file and more information can be found in this blog post: Haiti LiDAR imagery in Google Earth

NGA ALIRT LiDAR:

Access to NGA ALIRT LiDAR data are via the NGA Haiti ALIRT page, which provides an overview map of the collection area and a link to download ”Geospatial Data Files”.  Products range from movies and PDF visuals of data to DSMs in GeoTIFF format.

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

Posted on Tue, May 04, 2010 by C. 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:

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Golden Gate LiDAR Project

Posted on Mon, April 05, 2010 by C. Crosby in Data • News

Another new LiDAR data collection funded with stimulus dollars that I recently became aware of is the ARRA Golden Gate LiDAR Project.  Led by San Francisco State University and funded by USGS ARRA, this project will collect data in coastal regions around San Francisco:

The project extent is based upon the watershed boundaries for all watersheds that contain the lands of Marin County and San Francisco County. It also includes the watersheds that contain Point Reyes National Seashore and the Golden Gate National Recreation Area.  The area of interest includes watersheds that are also located in southern Sonoma County and northern San Mateo County and when combined total ~835 square miles (planimetric estimate) of area. The project area includes the Marin Peninsula and San Francisco Peninsula that form the western edge of San Francisco Bay and San Pablo Bay.

Like the Northeast ARRA data collection I just posted about, the Golden Gate data sound like they will be collected to the meet the USGS-NGP Base LiDAR Specification with 2m nominal point spacing.  The data will be available via the USGS CLICK archive and will be incorporated into the USGS 1/9 arc-second NED layer.  The project website indicates that data collection may have begun last month.

For the OpenTopography community, these Golden Gate data are likely of great interest given that they expand upon the existing Bay Area LiDAR coverage provided by the OpenTopography-hosted Northern California EarthScope LiDAR and are designed to capture full watersheds.  Although lower resolution than the data collected by EarthScope, these data should be very interesting to a large number of users.

Map of the collection area from the Golden Gate LiDAR project website:

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LiDAR for the Northeast Project Funded

Posted on Mon, April 05, 2010 by C. Crosby in Data • News

A proposal for an extensive LiDAR collection of coastal regions of the Northeastern U.S. (New York, Connecticut, Rhode Island, Massachusetts, New Hampshire, and Maine) has been funded by the USGS with American Reinvestment and Recovery Act money.  The proposal, led by the Maine Office of GIS, is to collect LiDAR data over ~13,500 square miles.  MEGIS has an announcement about the funding.  From the LiDAR for the Northeast proposal (PDF):

Full or partial county lidar collections for all coastal areas in New York, Connecticut, Rhode Island, Massachusetts, New Hampshire, and Maine, including many coastal watersheds and subwatersheds. The total area proposed is 13,561 square miles in a continuous swath with no gaps, including all coastal towns in the region, towns adjacent to major tidal rivers, and other adjacent areas deemed important to the stakeholders. Of this area, 8979 square miles is new data, 1056 square miles is being collected by FEMA, and 3526 square miles of other existing data (not in CLICK or NED). Only 58 sq. mi. of this entire region is currently in CLICK and only 410 sq. mi. are in the 1/9th arc-second NED

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Map of the project area from the LiDAR for the Northeast proposal:

Data will be collected to the meet the recently released USGS-NGP Base LiDAR Specification, and thus will have 2m nominal point spacing.  As is required by the ARRA LiDAR RFP, all of these data will eventually end up in the USGS CLICK archive and will be incorporated into the USGS 1/9 arc-second NED layer.

It appears that the proposal pulls together an impressive collection of federal and state agencies and non-profit organizations to build a consortium and generate matching funds.  This looks like a great project and will produce a lot of new and valuable data. 

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Haiti LiDAR imagery in Google Earth

Posted on Thu, February 11, 2010 by C. Crosby in 2010 Haiti EQ • Data • Google Earth

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 C. Crosby in 2010 Haiti EQ • Data • 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 C. Crosby in 2010 Haiti EQ • Data • 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 the actual LAS file)

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 C. Crosby in 2010 Haiti EQ • Data • 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 C. Crosby 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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