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Created on March 07, 2010
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Written by Matt Ball
The attendees at ILMF 2010 had their choice of a good variety of sessions that were delivered by a good mix of industry, academia, policy creators and practitioners. The primary track centered on bathyetric LIDAR, data fusion, data acquisition and mobile LIDAR. The fact that LIDAR processing is still in its infancy, with hardware far exceeding the capability of software, was very apparent at the event. With each detailed use case presentation the focus of the question and answer period largely revolved around process issues as users quizzed each other to learn methodology and best practices.
Keynote Highlights Steps to a National Standard
The opening address by H. Karl Heidemann seemed somewhat of an odd choice to lead off the event with its in-depth focus on the LIDAR Base Specification that is being developed by the USGSONGP. The presentation highlighted the need for a unified national standard in its promotion of a national LIDAR dataset that is gaining momentum in Washington. I worried a bit about the interests of an international audience, and got bogged down a bit in an alphabet soup of acronyms, but the need for the specification was also well covered to give an understanding of the policy and technology issues that are being debated.
ASPRS Presents Hot Topics
The ASPS Hot Topics session on the first morning of the event provided a good introduction about emerging areas of interest including, mobile LIDAR, data collection, high-performance computing for better performance, and training and education initiatives.
In the mobile session, we learned of the considerable expense of these systems, and also some of the paradigm-shifting possibilities from this technology. This introductory session was followed by a whole series of talks that delved into various applications of the technology.
Matt Bethel, the manager of systems engineering at Merrick and Company, provided a good overview of computer performance issues in the data-intensive LIDAR application space at the ILMF conference in Denver. Merrick has benchmarked a lot of different approaches in their need to increase throughput and decrease processing time for faster results. A good portion of investment is on the hardware/software side in a LIDAR shop, but time to process also factors in greatly to bottom-line costs in this process-centric industry.
Haiti Effort Benefits from LIDAR
Ken Hudnut of the U.S. Geological Survey discussed the use of LIDAR for both the Chilean and Haiti earthquakes at the ILMF event. Using the same scale, he showed the dramatic difference in size and shake pattern between these quakes. The Chilean fault size area was 60,000 sq km vs. 600 sq km in Haiti. He overlaid the PAGER product and combined with population centers, showing that the shaking patterns happened greatest in the densest areas in Haiti.
The Chilean earthquake was 500 times more energetic than in Haiti, although there were 300 times more deaths in Haiti, making it the sixth most lethal in recorded history. Given the level of deaths, the U.S. Geological Survey is studying Haiti in detail, with funding from USAID to understand what happened there, particularly since the global hazard map didn’t pinpoint the Haiti fault as a significant hazard area.
The LIDAR and imagery combination provides a means to quantify land changes, and to assess in the field when different land changes occurred. Feature offsets give a sense of the slip rate along the fault over time. LIDAR is tremendously powerful for the assessment of offset features to understand where damage occurred in the past.
The USGS will be doing an overall hazard map of the area, and LIDAR has been very helpful to assess damage, understand coastal deformation issues, and has enabled the determination of the location of the fault in areas where it wouldn’t be detectable before.
Fusion Points to New Possibilities
The fusion of both LIDAR and hyperspectral imagery for the creation of realistic urban models for simulation purposes was the focus of a presentation this morning at ILMF by Raul Campos-Marquetti, senior hyperspectral scientist at Merrick & Company. The ultimate purpose of this model was a simulation for military training purposes by the U.S. Army’s RDECOM.
Hyperspectal provided the means to classify features and to create a spectral library of road surface types, roof types, vegetation classifications, and an understanding of different building types. The hyperspectral classifications were then used to do a pixel by pixel, point to point fusion to create an informed 3D model with real world features and land cover/land use classifications.
The “physical morphology” model informed the synthetic creation of building exteriors and interiors based on real observation of different material types. The resulting large-scale city model was more of a true modeled reality than what can be accomplished with simply point clouds, because the classifications informed more realistic simulation that could take into account the physics of the different material types.
Monitoring Aids Environment Understanding
A combination of aerial and terrestrial LIDAR are being used to monitor forests in the research work conducted by Monika Moskal, professor at the University of Washington and director of the Remote Sensing & Geospatial Analysis Laboratory, who spoke this week at the ILMF conference about the unique and well-suited contributions of LIDAR for forest study. The detailed modeling of forests in the Pacific Northwest are being used for a variety of purposes, including the close study of the riparian forest/water interface and function for the suitability and sustainability of salmon habitat.
Moskal emphasized the repeatability of LIDAR measurements for ongoing observations that far exceeded the accuracy of field observation as well as the ability to observe large areas. The high-resolution forest modeling is proving superior for modeling Leaf Area Index or the roughness of the forest canopy as well as dbh for the size of tree trunks. Armed with this data, foresters can determine wood supply potential, forest fire potential, and better understand the forest/water intersection.
The ongoing study of the riparian areas extends beyond the suitability of habitat toward the ecosystem services of the forest for quality drinking water. Water is seen one of the leading potential marketplaces according to Ecosystem Marketplace, and in order to begin trading on the services that the forests provide for greater water quality, we will need to fine tune our means to model and monitor this valuable service.
Overall the event provided a good overview of the exploding use of LIDAR collection, processing, visualization and analysis. LIDAR is rapidly gaining favor over traditional photogrammetry and other applications, but there are still plenty of technological hurdles that need to be overcome in order to spur wider adoption.
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