TRACK 1 Airborne Surveying
Wednesday, June 24 10:30 am – 11:00 am
Horizontal Accuracy Assessment and Adjustment Tools for Airborne Lidar Data
Lewis Graham (GeoCue), John Ray (Ohio DOT), Martin Flood (GeoCue)
| Historically, vertical accuracy has been the primary figure of merit reported for airborne lidar data sets. Typically this analysis has been done by comparison to known ground check points. Both commercial software and proprietary tools have been developed to make adjustments to data sets based on minimizing vertical errors, with the assumption that if the vertical error is minimized, the horizontal accuracy specification should be met as well. Horizontal accuracy, when reported separately, has not been as rigorously measured and there are fewer tools available for calculating and applying purely horizontal corrections to large point data sets. However, with the increasing use of lidar-derived “images” such as lidar orthos and lidar synthetic stereo models, knowledge of the horizontal accuracy of the data is essential to project error modeling. We will present new assessment tools and techniques for assessing the horizontal geometric accuracy characteristics of lidar data and for applying global data adjustments without any apriori knowledge of, or access to, the sensor hardware. The techniques presented are based on research done in conjunction with the Ohio Department of Transportation and Ohio State University and commercially available in GeoCue Corporations’ “Feature Matching and Adjustment System”. Application of these and similar tools show great promise for deploying lidar as engineering tool of choice. We provide practical examples in highway project analysis as well as ideas for future work. |
| back to agenda |
Wednesday, June 24 11:00 am – 11:30 am
Laser Point Block Adjustment – Empirical Results
Peter Friess, Optech
| Airborne laser mapping provides as primary product a 3D point cloud. A methodology is presented for controlling and verifying the accuracy of the point cloud, not just locally for control areas, but for the entire project area. The approach is analogous to the photogrammetric block adjustment. It is assumed that a project area is covered with flight lines which overlap to some extent, as well as with an additional cross flight line. The overlap areas provide redundancy, not on a point to point basis, but with respect to the surface scanned. Planar surface features are detected and used as tie- and control features. A least squares adjustment is formulated that minimizes the weighted quadratic sum of the observation residuals at the tie- and control planes by estimating correction parameters of the mathematical model for the laser point computation. The goal is a geometrically correct laser point cloud, one that is free of systematic errors and for which the accuracy is given in form of standard deviations for the individual laser points. The approach is completely automated. Empirical results demonstrate its capabilities. |
| back to agenda |
Wednesday, June 24 11:30 am – 12:00 pm
POSPac MMS for Increased Accuracy and Productivity
of Airborne Lidar Mapping
J. Hutton, Applanix
| GNSS-Aided Inertial Navigation for Direct Georeferencing of lidar point clouds is a well accepted technology that has been in use since the mid 1990’s. Position accuracies of better than 10 cm RMS horizontal and 15 cm RMS vertical are routinely achieved using post-processed kinematic ambiguity resolution (KAR) differential GNSS processing along with specific operational restrictions that are necessary due to the nature of the airborne environment. These include: flying slow rate turns of less than 20 deg bank angle, flying less than 30 km from a reference GNSS receiver in order to correctly fix integer ambiguities, and keeping the maximum baseline separation to less than 75 km once the ambiguities are fixed. Each of these restrictions significantly reduces the efficiency of airborne lidar mapping, and hence increases the overall cost. This presentation introduces the new tightly coupled Applanix IN-FusionTM technology and Applanix SmartBaseTM Post-processed Virtual Reference Station module implemented in POSPac MMS 5, that together not only solve these problems, but also increase the overall accuracy and reliability of the positioning solution. |
| back to agenda |
Wednesday, June 24 1:00 pm – 1:30 pm
Powerline Surveying: New Software Tools for Production Processing
Eugene Medvedev, Altex Geomatica
|
The modern aerial lidar productivity and accuracy have increased
greatly recently, which makes it possible to achieve principally
new results while their applauding for power line survey. This field
of investigation is typical for Altex Geomatica company since 90th
decade.
The new modules on power line processing are included into software package Altexis 7.1 and are commercially available currently. New program modules provide the following new possibilities: - Almost 100% probability of wire detection, geopositioning and
vectoring thru lidar points processing; The new software features are achieved by applying of new mathematical methods, in particular Kalman filter. |
| back to agenda |
Wednesday, June 24 1:30 pm – 2:00 pm
Aerial camera systems in corridor survey
Tobias Toleg, Rollei
| Rollei Metric, since October 2008 part of the Geospatial division of Trimble, started around six years ago with aerial digital medium format metric camera solutions. Especially, the medium format camera solutions found their way very early into the corridor survey applications, like power- and pipeline and road and highway survey, mostly in combination with lidar systems, e.g. ALTM. Where large format analogue cameras cover wider flight passes and opening angles cannot be aligned with lidar systems, medium format become the first alternative. Digital images are in this case much more cost effective and much faster in post processing. The Rollei Metric solution AIC (Aerial Industrial Camera) found their way early into this new product segment and was optimized in the following years to serve the needs of corridor mapping applications much better than any other solution. Rollei Metric/Trimble has sold around 120 systems, which are in operation world-wide. The main focus of these camera systems is reliability, efficiency and a modular design, which allows operators to configure the camera to the mission. In these configurations the camera can be used for RGB or IR imagery, which in power- and pipeline applications is a standard today. The modular design allows upgrading the camera to any new sensors or optical lens systems, without replacing the complete camera. Even adding single camera heads to a system to increase efficiency or capture new targets is possible with the Trimble AC. Technically the Trimble AC operates the latest CCD sensors and electronic shutters, can be coupled to IMU/GPS and FMS systems, and is embedded into high class lidar systems. |
| back to agenda |
Wednesday, June 24 2:00 pm – 2:30 pm
Applications and Benefits of Airborne Lidar Technology
for Transmission Line Asset Management
R. Valerie Ussyshkin, Michael Sitar
Optech Incorporated
|
Being the fastest and most efficient means of acquiring high-density,
high-accuracy, geo-referenced spatial data, airborne lidar technology
is today a widely accepted and popular tool among power utility
companies. As the supply of non-renewable energy sources has dwindled
over the last few decades, the demand for energy has begun to outpace
the available supply in many countries. In response to this growing
imbalance, the power utility industry is challenged not only to
develop new energy sources, but also to maximize the efficiency
of existing power line corridors by improving, upgrading and managing
their transmission line assets and infrastructure. An important
information source enabling comprehensive analysis of power line
networks includes accurate spatial data of the transmission wires
themselves, the underlying surface terrain and surrounding vegetation
throughout the transmission corridor.
This paper describes applications and benefits of airborne lidar technology for transmission line asset management and the typical workflow of lidar data collection and analysis used in power line corridor applications. The key advantages of ALTM lidar systems manufactured by Optech Incorporated are discussed in the context of corridor applications. |
| back to agenda |
Wednesday, June 24 3:00 pm - 5:00 pm
The Global Market for Airborne Lidar Systems and Services
Tina Cary, Cary and Associates
|
Marketing professional services is always challenging, especially in highly technical fields, and tough economic times increase the challenge. This 2-hour workshop will provide information and tools to help participants meet the challenge.
The following topics will be presented:
The section on marketing basics provides an overview of marketing as a process, and covers such traditional topics as SWOT analysis, sales funnels, and the marketing mix with examples in the geotechnologies. The next component of the workshop describes the market for airborne lidar services in terms of applications and market segments, and demonstrates the role market intelligence can play in developing a marketing plan. The final component covering tips and tactics will include suggestions particularly appropriate for tough times. |
| back to agenda |
Thursday, June 25 10:30 am – 11:00 am
Quality Control of Lidar Data
Ayam F. Habib, Ana Paula Kersting, Ki-In Bang
The University of Calgary
| Lidar systems have been widely adopted for the acquisition of dense and accurate topographic data over extended areas. Although the utilization of this technology has increased in different applications, the development of standard methodologies for quality control of the derived data has not followed the same trend. In other words, a lack in reliable, practical, cost-effective, and commonly-acceptable methods for quality evaluation is evident. A frequently adopted procedure for quality evaluation is the comparison between lidar data and ground control points. Besides being expensive, this approach is not accurate enough for the verification of the horizontal accuracy, unless specifically-designed targets are used. This contribution is dedicated to providing an accurate, economical, and convenient quality control methodology for the evaluation of lidar data. First, a brief discussion of the lidar mathematical model will be presented together with an analysis of possible random and systematic errors and their impact on the resulting surface. Based on this discussion, a tool for evaluating the quality of the derived surface is proposed. In addition to the verification of the data quality, the proposed method can be used for evaluating the system parameters and measurements. Experimental results from simulated and real data will be used to demonstrate the feasibility of the proposed tool. |
| back to agenda |
Thursday, June 25 11:00 am – 11:30 am
Real-time In-flight Lidar Quality Control
Stephan Landtwing*, Roland Stengele, BSF Swissphoto AG (Switzerland)
Philipp Schaer, École Polytechnique Féderale de Lausanne (Switzerland)
| The last years have seen at least two major trends in the context of airborne lidar projects: The dramatic increase in scanner hardware capabilities (i.e. PRF) and the ever-increasing demand for rapid turn-around times and elevated levels of quality control. Combined, these call for reliable quality assessment of massive data volumes within or shortly after the airborne survey campaign – an area where today’s ALS systems are sadly lacking. This has led some lidar service provider – such as BSF Swissphoto – to construct their custom QA/QC tools for quickly checking the collected data with respect to gross errors, complete area coverage and point density. This task is even more important in rugged terrain, when operating from a high-dynamic helicopter platform or when scanning in a tilted configuration. In cooperation with the Swiss Federal Institute of Technology in Lausanne, BSF Swissphoto has now developed an in-flight quality monitoring tool that allows assessing the quality of recorded data “on the fly”, featuring real-time processing of the GPS/INS data and subsequent georeferencing of the laser returns. The tool is capable of displaying the scanning progress in real-time and detecting data gaps immediately after terminating the strip. We will present the adopted strategy for data processing and communication in order to achieve scalable distribution across a network of computers and explain how the architecture of the program components and interface definitions allow portability of the tool to any ALS system. Further we discuss first experiences with this tool within airborne survey projects using a custom-built hand-held scanning system (“Scan2Map”) that demonstrate its successful application in practice. |
Thursday, June 25 11:30 am – 12:00 pm
3-D Urban Feature Extraction
James S. Blundell, David W. Optiz, Overwatch Geospatial Systems
| Government and industry require automated feature extraction (AFE) software to collect 3-D urban features from terrestrial and airborne lidar data in a timely and cost-effective manner to support the ground-based Warfighter operating in the urban battlespace. Vehicle-mounted terrestrial lidar systems have the capability to capture very accurate 3-D measurements of the urban environment, with spatial resolution on the order of 5 centimeters or less. The 3-D imaging capability of these collection systems is negated, however, by a lack of commercial software tools capable of exploiting terrestrial lidar datasets with a high degree of automation. Current approaches for creating high-resolution 3-D urban models are expensive, requiring thousands of man-hours to digitize feature geometries, assign textures to features, and then attribute features. Overwatch Geospatial Systems (Overwatch) has developed a unique capability to automatically extract 3D urban features from terrestrial lidar data including building facades, doors, windows, poles, trees, vehicles and other urban features of interest. The Urban 3D Modeling Toolkit, designed as a plug-in for the LIDAR Analyst software, provides the geospatial community with a comprehensive and automated 3-D extraction solution for urban environments. |
| back to agenda |
Thursday, June 25 1:00 pm – 1:30 pm
Geo-referencing Hyperspectral Imagery Using Lidar Data
Ashley Tam and Tyler Ivanco, ITRES Research Limited
| Geo-referencing airborne or satellite-borne imagery requires surface height information. For conventional aerial photography, the primary concern is the surface object height data, which can be extracted from the stereoscopic imagery manually or automatically. Use of external height data is not mandatory for the geo-referencing process, however, digital hyperspectral imagery are monoscopic in nature as the main interest is the surface spectral information, thus external surface height information is required for geo-referencing hyperspectral imagery. The quality of the input information is one of the main factors that directly affect the positional accuracy of the geo-referenced images. A lidar system provides high precision and high-resolution height data, which is critical for processing monoscopic imagery. The accuracy differences between hyperspectral images processed using coarse DEM data and lidar data are compared. The software used to generate geo-referenced ITRES’ hyperspectral image data is presented. Example process results from actual projects are discussed. |
| back to agenda |
Thursday, June 25 1:30 pm – 2:00 pm
CZMIL: A New Bathymetric Sensor Design for Environmental Mapping
Grady Tuell, Ph.D., Optech International
| The Coastal Zone Mapping and Imaging Lidar (CZMIL) is a new airborne coastal mapping system designed to produce high-resolution, 3D, environmental data. The project is in the detailed design phase, with anticipated delivery of the first system to the U.S. Army Corps of Engineers in the fall of 2010. The CZMIL Data Acquisition System (DAS) and Data Processing System (DPS) have been designed following a data fusion paradigm to exploit a new topo/bathy lidar, spectrometer, and metric camera to maximum advantage. Anticipated data products are: continuous topo/bathy point clouds, DEMs, and reflectance images; high-resolution orthophoto mosaics; seafloor and beach classification maps; chlorophyll and CDOM concentration maps; suspended sediment maps; and shoreline vectors. The lidar component of the DAS is designed for continuous topo/bathy operation, and to achieve high performance in shallow, turbid waters. It will employ a narrow pulse, 10 KHz green laser, a segmented detector, and a circular scanner to produce sub-meter sampling on the beach and in shallow waters, and two meter sampling in deeper waters. In this presentation, we will show the conceptual design of the CZMIL DAS and DPS, the concept of operations, and illustrate anticipated data products using data acquired by the CHARTS system. |
| back to agenda |
Thursday, June 25 2:00 pm – 2:30 pm
MAPLE and PULSE: One Terrestrial and One Submarine Portable Device for Ground Calibration of Bathymetric and Aerial Lidar Survey Data
B. Long*, D. Cantin**, V. Robitaille* and F. Généreux**
* INRS-ETE, **INO
|
In recent years, Airborne Laser Bathymetry (ALB) has proven to
be a time and cost effective method for surveying extensive coastal
regions (Wozencraft and Irish, 2000). Along with gathering precise
topographic and bathymetric data, ALB systems are now being considered
for other applications like nearshore environmental classification,
small target detection, water column characterization, and sediment
budget evaluation. But, in general, the lack of ground truthing methods to investigate the fundamental principles of airborne lidar technology limits the mapping of sedimentary facies and biological habitats. It is a raison that INRS-ETE in collaboration with INO, develop two portable laser system prototypes that relate to different aspects of ALB technology. The first system, the multi-beam autonomous portable laser equipment (MAPLE) is a terrestrial and very shallow water system (0 to 3 m). MAPLE is mounting on a tripod and emiting two continuous laser signals of 532nm and of 1064nm. MAPLE is developed to improve the classification of geological facies and biological habitats, the optical signatures in heterogeneous environments, the evaluation of bioturbation, the characterization near bottom turbidity layers and seafloor sedimentary features. The second system, the portable underwater lidar system equipment (PULSE), is dedicated for shallow-water environment (2 to 30m). PULSE uses a submarine optical module and the lidar technology to emit a pulsed laser signal of 532 nm. PULSE is designed to study the variations in laser pulse waveforms in function of the different physical characteristics of the water column and the seafloor reflectance signal function of the sedimentary facies and biological habitats. |
| back to agenda |
Friday, June 26 10:30 am – 11:00 am
Individual Tree Crown Delineation using Combined Lidar Data and Optical Imagery
Wen Zhang a,*, Baoxin Hu a, Linhai Jing a, and Murray E. Woods b
a Department of Earth and Space Science and Engineering, York University
b Senior Analyst Forested Landscape, Ontario Ministry of Natural Resources
|
The development of advanced high-spatial resolution optical imager
and small foot-print lidar instruments provide a good opportunity
to identify forest species identification at the individual tree
levels. It also challenges to develop advanced methodologies to
take fully use of the high information content in the data. For
high-spatial resolution imagery, a pixel covers only a small part
of a tree canopies. As a result, the traditional pixel-based data
analysis is not effective any more. It is important and critical
to segment individual pixels into meaningful objects, such as individual
tree crowns. As a result, individual tree crown delineation is a
critical step in automatic forest species classification.
Individual tree crowns are conventionally segmented mainly based on the spectral variations of forest canopies derived from multi-spectral data. With this aspect, full tree crown segmentation is negatively affected by the anisotropic reflectance property of tree canopies. This effect is especially significant for the open canopies. On the other hand, tree crowns tend to have a distinct edge in the 3D data clouds collected by a lidar instrument, especially for open canopies. For close canopies, trees grow together, which makes the distinction between crowns in the lidar data are less evident. To make advantage of the complementary information provided by optical imagery and lidar data in individual tree segmentation, a novel algorithm is proposed. With this method, individual trees are first identified by intelligently using the height information derived from lidar data. After the seed points are generated, as each seed point represent each of the identified trees, an advanced regional growth segmentation method is used to delineate individual tree crowns using combined multispectral imagery and lidar data. The proposed method is validated using the optical and lidar data collected over the Petawawa and Swan Lake Research Forests, Ontario. Based on visual comparison, 90% of the tree crowns have been successfully segmented on an automatic basis. Also, results have been compared with commercial software Definiens with a better segmentation for high density stands has been shown. |
| back to agenda |
Friday, June 26 11:00 am – 11:30 am
Airborne Laser Scanning Based DTM Production Workflow in the National Land Survey of Finland
R. Ilves, National Land Survey of Finland
|
National Land Survey of Finland has started a new
national digital terrain model project using airborne laser scanning.
The new production line workflow is described. The description includes:
project planning, mission planning, specifications, quality control,
system calibration, georeferencing, strip adjustment, automatic
point classification, interactive point classification and final
products.
For the data processing, TerraSolid, Espa Systems and in-house software were used. TerraSolid and Espa Systems are Finnish companies, located in close proximity to the NLS’s main office. It has been a good and productive software developing period between NLS and the companies. The whole production line is quite unique. There is direct connection to the national topographic database and stereomodels are used in the interactive work. The main products are classified point cloud and 2 m grid DTM and the coverage will be nationwide. The production has started well and many clients have communicated to us that the new dataset is perfect for their use. Some examples of the different customer cases will be introduced in this presentation. |
Friday, June 26 11:30 am – 12:00 pm
Using LiDAR data for small hydroelectric power plants pre-feasibility studies
Mauricio Müller, Daniele Felix Zanodona, LACTEC
|
During the last years, the world has been faced with an imminent
crisis of energy and the global warming issue, making strategic
the exploration of new sources. Alternatives like oil or even nuclear
plants have adverse reactions from the society and researchers.
Renewable sources like wind, solar and hydro are becoming more and
more demanded.
South America still has many sites for hydropower generation.
Since the bigger sites are all exploited, the new trend is the small
power plants located near small waterfalls. The crucial information for the analysis of the feasibility of a particular hydropower site is the presence of a minimum fall and water flow. However, in development countries, the lack of information is common. The topographic data available came from surveys carried 40 years ago. When available, the standard scales are around 1:100.000 and 1:50.000 providing topographic contours with 40 to 20 meters intervals. Hydrological data is also a problem, with incomplete series and unsatisfactory geographic distribution. lidar technology came to fill the gap of topographic data, with more accurate and reliable data. This work presents how a detailed Digital Terrain Model - DTM can be generated and used to find small waterfalls that have potential for hydropower generation. These DTM can also feed hydrometeorological regionalization models
enabling the determination of long term medium discharge, maximum
and minimum discharges, and |
Friday, June 26 1:00 pm – 1:30 pm
Using large Lidar datasets with the new Oracle 11g Spatial 3D data types
Roberto Orsi, ABACO
|
This presentation shows how ABACO’s technology helped to use large
scale lidar datasets in the new 3D data types of Oracle 11g Spatial.
The results were obtained under some projects, and we will provide
a live demo using billions of points stored in the Oracle Point
Clouds data model.
ABACO has included this new functionality into its own Web 3D navigation viewer, which includes navigation using TINs (surface modeling), point clouds (lidar) and 3D building models. The results are greatly impressive and allow amazing real-time Web3D navigation through a large scale 3D data types stored within Oracle 11g and supporting also simple and/or topology features data, as well as georaster data. |
| back to agenda |
Friday, June 26 1:30 pm – 2:00 pm
CoCo® A patented innovative technology for Co-Mounting and Co-Registering Imaging Sensors with LiDAR and Other
Dr. J. Armando Guevara, Joe McCoy, M7 Visual Intelligence LP
|
GeoImagIng the World Online! In 1998 M7 Visual Intelligence (“M7 VI”) designed and made operational its first generation of digital aerial imaging and mapping sensors. In 2001 it acquired its first lidar. Since then, M7 Visual Intelligence has been at the leading edge of innovation by improving the operational use of lidar technology tightly coupled with aerial digital cameras (medium to larger frame format) in general, and recently in specific, with its 3rd generation imaging sensor technology, Iris One®. CoCo®, the “Vehicle Based Data Collection and Processing System and Imaging Sensor System and Methods Thereof” U.S. Pat. App. No. 11/581,235, is a technology made operational in 2002 and which M7 VI in working with its patented camera systems, found that errors in imagery were greatly reduced if the sensors were rigidly mounted and registered to each other. As an improvement to the technology, U.S. Pat. App. No. 11/581,235 (“the Co-Co Application”) was filed on October 11, 2006. The Co-Co application was filed as a continuation-in-part of U.S. Pat. App. No. 10/664,737, which granted as U.S. Pat. No.7,127,348. The claims are directed toward an incorporation of the co-mounted and co-registered nature into M7 VI’s system for terrain mapping, and with that obtain unprecedented sensor integration performance for large scale and large geographic area mapping. This paper describes the CoCo® technology, its implementation and the operational improvements (data collection, time, cost) obtained by flying in tandem the Iris One sensor and lidar. |
