2003 INTERNATIONAL CONFERENCE AIRPORTS: PLANNING, INFRASTRUCTURE & ENVIRONMENT

Transcription

1 AIRPORTS: PLANNING, INFRASTRUCTURE & ENVIRONMENT AIRBORNE AND SPACEBORNE REMOTE SENSING TERRAIN MAPPING FOR PLANNING AND DESIGN OF TRANSPORTATION INFRASTRUCTURE ASSETS Waheed Uddin Associate Professor of Civil Engineering and Director, CAIT The University of Mississippi, Carrier 203 University, MS , USA Voice: (662) Fax: (662) Henrique Garcia Momm Graduate Research Assistant, CAIT Department of Civil Engineering The University of Mississippi, Carrier 203 University, MS , USA Paper

2 ABSTRACT This paper discusses integration of innovative airborne laser mapping technology, spaceborne high-resolution satellite imagery, and traditional aerial photography with geographical information system (GIS) applications for producing digital terrain models and databases for applications in transportation planning, design, monitoring, and environmental assessment. Results of a recent NASA study are presented, evaluating data accuracy, efficiency, time saving and cost-effectiveness of the remote sensing laser technology as compared to the conventional ground-based methods for terrain data acquisition and mapping. Airborne terrain mapping laser technology permits 15-cm elevation accuracy and 1-ft contours. There are less operating constraints such as cloud and vegetation cover, traffic and usage, or time of day. Modern spaceborne remote sensing satellite imagery is very attractive because of its low cost and high resolution. Appropriate data analysis techniques and imagery data analysis can provide up-to-date information on airports, highway corridors, and surrounding areas. The digital terrain database developed from these remote sensing methods can be easily integrated with an existing infrastructure management system. Examples of three-dimensional visualization of these remote sensing data are presented for selected highway and airport infrastructure assets. KEY WORDS Remote sensing, laser, satellite, transportation, infrastructure, terrain, mapping, airport 2

3 BACKGROUND AND OBJECTIVE Overview of Transportation Infrastructure Management The quality of life of a nation is directly related to the level of infrastructure development. Infrastructure includes all facilities that provide essential public services of transportation, utilities, energy, telecommunications, waste disposal, park lands, recreation, and housing (1). Transportation infrastructure is responsible for the transportation needs of the public, distribution of all goods throughout a nation, and economic development. Transportation infrastructure can define the competitive level of a nation s performance regarding time and cost. The combination of transportation infrastructure assets, as can be seen in the metropolitan areas, constitutes a challenge for the infrastructure management process, where the inventory and condition assessment data are considered a fundamental part of this system. In order to provide this data, modern airborne and spaceborne remote sensing technologies have made it possible to collect accurate georeferenced digital terrain data efficiently in a proper format (1). Overview of Computer-Aided Design Tools Engineering designs are communicated through a technical drawing process. The graphical utilization of engineering drawings has changed over the years following the developments of the microcomputer in the past two decades. Along with the computers advancement, a new graphical methodology of computer-aided drawing and design (CAD) was introduced, which improved the revisions and reproductions with immense time and cost savings. One powerful tool of the CAD systems is the three-dimensional (3-D) drawing and solid modeling capability, offering all the advantages of the two-dimensional (2-D) drawing with the addition of spatial visualization and detailing process. In a 2-D drawing, the third dimension is implied and left to the imagination of the viewer. The 3-D drawing offers the option of generating standard 2-D multi views and several isometric views, which can be shaded, rendered, and then used as models for animations, structural analysis, and prototype generation. Objective The major objective of this paper is to demonstrate the use of new remote sensing technologies and CAD tools to improve the design and visualization of new and existing transportation infrastructure assets. Applications of the new remote sensing terrain data and 3- D visualization include the development of dedicated programs for roadway and airport design. Several 3-D computer visualization examples are included in this paper, showing flythrough animations over roadway right-of-way and airfield runway. COMPUTER VISUALIZATION TECHNOLOGIES FOR TRANSPORTATION INFRASTRUCTURE The CAD technologies are able to improve the productivity and skill of drafters and engineers by using digital data formats to create, revise, print, and store the drawings on computer storage media with reductions in paper storage needs. It also improves the communication between the users, who can send and receive the data through computer networks and the Internet. Through the combined use of CAD systems with word processing and spreadsheets programs, 3-D solid rendering, and animations programs, different visualizations and virtual 3

4 reality applications can be developed. In engineering design the CAD drawings can be used along with finite element programs to simulate and evaluate the structural behavior of the designed elements. Transportation infrastructure assets promote significant influence in the environment where they are constructed. New design policies are being developed by many transportation agencies to minimize the impact of construction projects and preserve environmental, scenic, aesthetic, historic, and natural resource values of the area. Depending on the type and level of importance of the project, it might be needed to present the project to the non-engineering public such as planners, researchers, environmentalists, and other citizens. In order to provide a better understanding of the future project, visual aids like pictures, charts, drawings, and computer animations are used. Computer visualization and animations deserve special attention because of their capability of changing the viewer s perception. This can help nonengineers and the general public in understanding the project and the technical part involved in the design to identify future conflicts and issues regarding the construction and implementation of the infrastructure facility. GIS BASED DECISION SUPPORT SYSTEMS FOR TRANSPORTATION PLANNING, DESIGN, AND ASSET MANAGEMENT Database development and management programs that offer temporal and spatial identification of the data have gained widespread acceptance in the area of transportation planning, design, and asset management. Temporal data identification represents a historical record of construction, maintenance, and evaluation data. Spatial data identification relates the data to the physical location of the facility in the infrastructure by using geocoding (geographical coordinate description). These tasks can be performed through the use of a geographical information system (GIS) software. The GIS software is a powerful geospatial tool to engineering applications that links an attribute database to map features through logical relationships. GIS plays an important role in the transportation planning, design, and asset management as shown in Figure 1. It connects all elements of the asset management process, providing important information flux and storage (1,2). The use of GIS in integrated infrastructure asset management systems can reduce the cost of its implementation and maintenance within a public works agency. This provides an important source of information for the decision-support process. Additionally, all agency users can access geospatial data by sharing visual display on electronic maps and Internet sources. New technologies constitute multi-discipline concepts that not only involve the facility itself but also link it to the environment where it is located, to different issues that may be related to the asset, and to cost-effective data collection from innovative remote sensing noncontact technologies. 4

5 Traffic Signal and Control System Roadway and Roadside Inventory & Condition System LIDAR GIS ITS & Asset Management Traffic System Bridge and Drainage Inventory and Condition System Public Transit System Figure 1. Integration of transportation planning, design and asset management using GIS (2) REMOTE SENSING TECHNOLOGIES Conventional technologies such as aerial photography and ground survey have been used for photo record, land parcel management, route location of transportation corridors, topographic survey, digital terrain modeling, and contours generation for years in connection with transportation projects. Aerial photography suffers from several operating constraints. At present new remote sensing technologies such as airborne laser terrain mapping (ALTM) and high-resolution satellite imagery are being used for transportation applications as shown in Figure 2. These can be used to extract terrain elevations, contour maps, and the spatial location of infrastructure assets like right-of-way, edge of pavements, road centerlines, bridges, culverts, signs, and overpasses (3,4). Depending on the size of the infrastructure, the collection of georeferenced inventory and condition data by manual methods may require substantial investments. In the case of natural or orchestrated disaster, the assessment of damage and rebuilding can be costly and time-consuming if the inventory and terrain model data are not easily available (4,5). Spaceborne satellite remote sensing and airborne laser ALTM represent alternative solutions to aerial photography, offer relatively inexpensive data collection, and provide up-to-date information related to transportation infrastructure assets. Some of the advantages of the new remote sensing technologies over the conventional mapping methods are: a) Data is collected and stored in digital format. 5

6 b) Time is saved for data collection and treatment. c) Greater area of coverage is possible. d) Data collection is subjected to lesser topographic and weather operating constraints. Aerial Photography Aerial photography presents a broader spectral resolution than that of the human eye, increasing the identification of objects by using tone, texture, size of object, shape, shadow, pattern, and association. The aerial camera is a passive sensor that operates in the visible band of the electromagnetic spectrum of light. After traveling in space and reaching the earth s surface, the light is reflected in various wavelengths. The amount and frequency of the wavelength are defined by the physical properties of the element, such as water content, chemical composition, and density. Visible light consists of blue ( µm), green ( µm), and red ( µm). Similarly, the other divisions are ultraviolet ( µm), middle-infrared (1.3 3µm), thermal infrared (3-14 µm), and microwave (1mm 1m) (2). Aerial photography collected over a time period provides historical record of data, offering the possibility of observing changes in the landscape with time. There are many applications where these bands are sufficient. In other cases specific bands are required to study particular features. Some of these sensors have been mounted under spaceborne remote sensing platforms. Figure 2 shows some examples of orthophoto products from aerial photography. (a) (b) Figure 2. (a) Aerial photograph of Atlanta (Hartsfield International Airport), Georgia, USA (6) (b) Orthorectified georeferenced digital photo mosaic from the Raleigh Bypass project, (c) Zoom-in showing the details of georeferenced orthophoto for the Raleigh Bypass project, Mississippi, USA (7) Photogrammetry, the science of making topographic measurements from the aerial photography, has long been used for terrain mapping data collection and interpretation. Some of the photogrammetry techniques used in the process include the scale of the photography, object dimensions (height and length), area, and perimeter. In addition when multiple overlapping aerial photographs are used, precise ground coordinates (x, y, and z) can be (c) 6

7 obtained. A grid of elevations can be generated by performing an aero-triangulation of the photography using photogrammetric systems, ground-control points, and camera-calibration information. The use of aerial photography for terrain mapping data can produce an accurate terrain corrected orthophoto that can be also directly used in GIS and CAD systems for different applications covering large areas with a minimum of ground control points. For highresolution topographic mapping applications, the aerial photographic mission is flown at low to medium altitude (500 to 1,000 m) to provide 15-cm elevation accuracy during the leaf-off period in early winter or early spring when there is no snow on the ground. The aerial photography productivity may be influenced by other operating air constraints such as vegetation cover, bad weather, time of day, and aviation regulations. The time of processing the aerial photos until the final product of the DTM can be considered as another disadvantage of this method when compared to the modern remote sensing technologies such as highresolution satellites and LIDAR (7,8). Spaceborne Satellite Imagery The basic working principle of spaceborne remote sensing is that the electromagnetic energy, after being reflected from the earth s surface and passed through the earth s atmosphere, reaches the sensor. In the sensor this energy is recorded as an electrical signal and converted to digital data by an analog-digital converter. This data is then sent by telemetry to ground stations for post-processing which provide geometric and atmospheric correction and data restoration due to possible minor failures of the sensor. This is done with specific digital image processing algorithms. The spaceborne satellite system presents a broad number of spatial and spectral resolutions. The spatial resolution can vary from kilometers of the stationary satellites to meters of the new high-resolution satellites. Figure 3 shows some examples of the modern high-resolution IKONOS commercial satellite imageries collected over Oxford in northern Mississippi. The satellite system has some advantages over other remote sensing methods. It can cover larger areas due to the high altitude position during the imagery collections and can be considered cost-effective when used for large areas. It also offers the possibility of historical data evaluation because of the continuous data collection over the years. Considering the different sensors available, this technology can be considered a multi-sensor system with capabilities of spectral and spatial resolution. Because it is a remote sensing technology, it can reach inaccessible areas and directly provide digital data. However, for accuracy and reliability, it generally needs ground-truthing and verification, does not provide enough details for small areas (for example detection of cracks on a pavement), and requires professionals and dedicated software to interpret the images. 7

8 (a) MS Highway 6 intersection near West Oxford exit (b) Oxford Airport, close up of runway 9-27 Figure 3. IKONOS 1-meter imagery collected over Oxford in northern Mississippi on March 27, 2000 (imagery courtesy of Space Imaging, Inc.) Airborne LIDAR With the use of low-powered lasers and modern positioning instruments, the airborne LIght Detection And Ranging (LIDAR) technology (ALTM technology) has become a competitive low-cost, time-efficient alternative for topographic surveys and terrain mapping projects. The LIDAR technology uses the near-infrared (NIR) band of the electromagnetic spectrum (2,8,9) and measures the laser pulse travel time from the transmitter to the target and back to the receiver. Because the light speed is known, the distance can then be calculated. In this process an accurate timing system is needed to guarantee the resolution since the laser pulses are generally sent at 3,000 to 10,000 times per second. The aircraft positioning is recorded using an inertial navigation unit associated with avionics systems, a high accuracy global positioning systems (GPS) receiver system in the aircraft, and GPS base stations installed in known locations. With these combined equipments, it is possible to determine threedimensional georeferenced coordinates for each pulse and then correct the aircraft positioning in terms of roll, pitch, and heading, thus improving the accuracy of the system. The density of the ground points depends on the aircraft elevation, the number of pulses per time, the scanner angle, and the aircraft speed. To cover dense areas, multiples flights can be combined. For high-resolution topographic data, the LDAR mission is flown at low altitude as shown in Figure 4. After the field data collection process is completed, the data points already in the digital format are easily loaded in computer stations for processing and interpretation. Depending on the application, specific software can be used for final revision and analysis. An example of the use of special software is to remove vegetation to determine bare-earth ground elevations. This data is used to generate a digital elevation model (DEM). LIDAR measurements can archive DEM with horizontal accuracy better than 30 cm (12 in), and vertical accuracy of 15 cm (6 in) or less (3,8,9). 8

9 LIDAR mission at 500 m (1,500 ft) for 1-ft contour mapping Path of Laser Pulse Aerial photogrammetry at 3,000 m (10,000 ft) Mission flown at 730 m for Raleigh Bypass topographic mapping project H H Line of Flight Path Figure 4. Principles of air borne LIDAR and aerial photography field missions (7) The airborne LIDAR topographic technology presents several advantages over the traditional methods of photogrammetry and Total Station ground survey. Data collection using the field survey can produce accurate information. However, this method demands a team to measure distances and angles in the field and is thus time consuming and expensive. Photogrammetry uses stereoscopic analysis of aerial photos to generate the DEM in the post-processing step, which can also be time consuming. Using the LIDAR method, time consumption can be considerably reduced, since the data collection speed is very high, (up to 81 sq km or 20,000 acres per day), and the data is collected and stored directly in digital format (3). Furthermore, it can operate in difficult terrains with cloudy weather and at night. One important characteristic is the capability of canopy vegetation penetration -- even though most of the pulses reach the vegetation canopy and are backscattered, there are points that go to the ground. With this capability it is possible to generate a bare-earth DEM and digital terrain model (DTM) by using specific software to remove the vegetation obstruction (points backscattered from the vegetation canopy). INTEGRATION OF REMOTE SENSING AND GEOSPATIAL TECHNOLOGIES Comparison of Data Resolution 9

10 Earth observation and study have been conducted using data collected from remote sensing sources. Basically, these sources were operated from high-altitude and were used only for state and national level evaluations. Recently, new generation of remote sensing technology improved resolution significantly, and as a consequence new applications have been developed. Table 1 shows a comparison of the new high-resolution spaceborne and airborne remote sensing technologies (8,9). Airborne LIDAR, as described before, offers an important source for digital terrain mapping of infrastructures assets. Spaceborne satellites can be used for regional and national levels with a low cost and high spatial and temporal resolution. One of these new commercial satellites, IKONOS launched by Space Imaging in 1999, can offer spatial resolution of 1x1 meter for the panchromatic and 4x4 meters for the multispectral, and a temporal resolution of 3.5 to 5 days (10). The QuickBird 2, launched by Digital Globe in 2001, has a higher resolution of 62 cm (11). The combination of these resolutions with the selection of the appropriate remote sensing sensor based on the project needs can become an important tool for infrastructure design, planning, and management covering such subjects as land use and land change, the environment, transportation corridor, and disasters evaluation. Table 1. Comparison of the new high-resolution spaceborne and airborne remote sensing technologies (8,9) Temporal Satellite/ Spatial Spectral Footprint Resolution Airborne Resolution Resoltion (km x km) (days) Landsat 7 15 m 7 bands x 185 IKONOS 1 m 3 bands x 11 QuickBird m 3 bands x 16.5 ASTER VNIR: 15m IR: 30-90m 14 bands In Space Shuttle Variable Obrview 4 1 m 4 bands 3 8 x 8 SPOT m (A,B) 20 m (Mid R) 4 bands x 60 Aerial 9 2 x 2 9 at 3,000 Up to 0.15 m Visible band On Demand Photo m Airborne Very Dense Up to 0.15 m NIR band On Demand LIDAR * IR = Infrared, NIR = Near Infrared, VNIR = Very Near Infrared * LIDAR measurement at 500 m above terrain level: about 1 m x 1 m on ground Traditional methods of ground data collection and mapping generally produce data that must be imported or treated before being converted to digital format for the final product generation. Unfortunately, this process may result in errors, a poor level of detailing, and an increase in processing time. New technologies where the data is collected, treated, and the final product generated directly in digital format, reduce the time between each step considerably with improvements in accuracy and detailing. Combining different sources of data collection in digital format, as shown in the Raleigh Bypass Alignment Project in the 10

11 following section (7,8), can generate final products for multiple purposes, and these products can be easily stored and accessed by different users by using computer networks and Internet. SR35 Raleigh Bypass Alignment Project This remote sensing technology evaluation study was sponsored by the National Atmospheric and Space Administration (NASA), Stennis Space Center through the Mississippi Space Commerce Initiative (MSCI), and supported by the Mississippi Department of Transportation (DOT). The objectives, major topics, and results of this project are presented elsewhere (4,5,7,8). The Raleigh Bypass Alignment Project ( ) was conducted by the Center for Advanced Infrastructure Technology (CAIT) at the University of Mississippi to evaluate the airborne LIDAR remote sensing against Total Station and aerial photogrammetry. The area of study was a 9-km (5.8-mile) long highway alignment project near Raleigh in Smith County, Mississippi. This project s objective was to evaluate and to compare the data accuracy, efficiency, time saving, and cost-effectiveness of the airborne laser LIDAR and aerial photography, using a total station survey as ground truth. The LIDAR survey method collected the terrain data and GPS information in a two-hour flight. After the data collection, the data was then loaded into computer stations for future treatment and final products generation such as DEM, contour lines, color-coded map, flythrough, and 3-D visualization images. For this project 1-ft contour lines were generated from the DEM formed from the bare-earth data points, saving considerable time and reducing cost when compared to the other sources (7,8). Figure 5 shows the 0.3-m (1-ft) contours and DTM developed from the Raleigh Bypass LIDAR data ft contour (b) 3-D view of DTM Figure 5. Raleigh Bypass Project (CL stations to 60+00): contour and DTM (7) This flux of information can be managed by using a central database system with some advantages such as reduction of redundancy, data that can be accessed by different applications, increased update speed, and application of security polices. As mentioned before integrated infrastructure systems formed by different agencies can provide a valuable, effective gain on information management. GIS represents the central integration platform of this system linking georeferenced and attribute data from the different agencies. Each decision 11

12 can be based on technical criteria with information from design, construction, and history of interventions (maintenance, reconstruction, and rehabilitation) of the infrastructure asset (1). Roadway Alignment Design Program (RAD) Different commercial software packages for the geometric roadway design are available with various features and capabilities. The idea of the RAD program development started with the possibility of implementing a program through the use of the AutoLISP programming language under the AutoCAD environment where the entire CAD features available in AutoCAD can be used, reducing the need for graphical programming. The RAD program reads terrain data file from total station survey or LIDAR-generated contours. It reads or draws a roadway centerline using a set of user-defined designed criteria, and plots centerline profile and cross-sections along the proposed centerline. At the end, the program performs an earthwork calculation and plots the mass diagram (12). For brevity this program is not presented in detail here. 3-D Flythrough Animations Using 3D Studio Max Different agencies have been developing new policies to minimize the adverse impact of infrastructure development and also to preserve the landscape for environmental, scenic, aesthetic, and historic reasons. This implies that the proposed project needs to be evaluated by a multidisciplinary team and accepted by the general public. Computer animations offer an alternative solution for presentation and visualization of the project from concept to construction because of its capability of showing the designer s and audience s points of view. The use of CAD software to generate 3-D digital models and animations constitutes an important tool to enhance the understandability of complex engineering projects to a wide range of individuals who might not be involved with the design process. The 3-D CAD models offer 3-D views by using shading and rendering techniques. These CAD models, satellite imageries, photo, and LIDAR digital terrain models can be enhanced for virtual flythrough visualizations by using the 3D Studio Max software. The flythrough animations improve the visualization effects and also can serve as an important tool for the project understanding, especially for the non-engineering community. The output is generated in Audio-Video Interleaved (AVI) format, which is the Windows standard file extension for movie files. Figure 6 shows a screen capture from the animation files generated using the LIDAR data and orthophoto from the Raleigh Bypass project (12). 12

13 After draping digital orthophoto over the LIDAR-generated DEM/DTM (with no vegetation removal and vertical exaggeration factor of 1.5) Figure 6. Flythrough over a part of Raleigh Bypass project in Smith County, Mississippi AIRPORT APPROACH SURFACE AND OBSTRUCTION-FREE SPACE Airport planning and management is such a complex process because of the great number of variables that need to be observed. In the last few decades, air traffic has increased considerably, resulting in an economic stimulation in the surrounding areas of airports generating radical residential and industrial growth. These new activities in the vicinity areas of the airports demand special attention for the safety operation of the airport. Obstructions in the navigable air space are identified through the use of an obstructions free imaginary surfaces methodology with reference to the airport classification. Runway category: Precision-instrument runway Conical Surface Horizontal Surface Transitional Surface Transitional Surface Approach Surface Primary Surface Note: the conical surface slope was increased to highlight the surfaces differences for explanation purposes. Figure 7. FAR part 77 imaginary surfaces for airport obstruction space An Airport Terrain Model, Approach Surface, and Obstruction Free Space Design (AAD) program has been developed in the AutoCAD environment. This program can plot the 13

14 imaginary surface on the airfield over the satellite imagery and LIDAR-generated DTM for the airport area. Details of the obstruction space specifications and regulations by the Federal Aviation Administration (FAA) in the United States and by the International Civil Aviation Organization are presented by Uddin and Al-Turk (13). Figure 7 shows a schematic of the FAA imaginary surface according to the federal aviation regulations (FAR) part 77 (12,13). Figure 8 shows an application of the imaginary surface generated by the AAD program for the Oxford Airport in northern Mississippi. The 3-D flythrough is developed for the obstruction free imaginary surface over the background of IKONOS imagery (12). Figure 8. Examples of the flythrough animation frames showing the obstruction imaginary surfaces for the Oxford Airport in northern Mississippi (12) CONCLUDING REMARKS The engineering analysis and design process is in constantly changing because of technological innovations and development. Transportation infrastructure design, planning, and maintenance directly depend on correct, timely data to support the decision-making system. Remote sensing is one of these sources of data collection that can be directly applied in the area of transportation to support cost-effective decision-making on the project-level and network-level. Some of e major advantages of the modern remote sensing satellite imagery and airborne laser mapping data collection have been discussed with examples. Modern computer-aided drawing and design tools, computer visualization, and remote sensing data collection are some interdisciplinary methodologies that constitute a modern roadway and airport design process. High-resolution satellite imagery and airborne LIDAR are new remote sensing technologies that are used to improve the 3-D digital terrain data models in terms of accuracy and economy during the planning and design processes. These new applications can enhance the practice of managing of infrastructure assets. The Airport Terrain Model, Approach Surface, and Obstruction Free Space Design (AAD) generates airport terrain models and airport obstructions free imaginary surfaces using the terrain elevation data, airport classification, and runway geometric characteristics. The usefulness of 3-D 14

15 visualization of transportation projects is illustrated using several example applications of virtual flythrough animations. REFERENCES (1) Uddin, W., Ralph Haas, and W. Ronald Hudson. Infrastructure Management. McGraw- Hill, New York, (2) Uddin, W. Application of Remote Sensing and Spatial Technologies for Oxford ITS Integration Project, CD Proceedings, 9th World Congress on Intelligent Transportation Systems, Session SP5: Traffic Surveillance, Chicago, Illinois, October 14-18, (3) Al-Turk, E. and W. Uddin. Infrastructure Inventory and Condition Assessment Using Airborne Laser Terrain Mapping and Digital Photography. In Transportation Research Record 1690, Transportation Research Board, National Research Council, Washington, D.C. 1999, pp (4) Al-Turk, E. and W. Uddin. Infrastructure Inventory and Condition Assessment Using Airborne Laser Terrain Mapping and Digital Photography. In Transportation Research Record 1690, Transportation Research Board, National Research Council, Washington, D.C. 1999, pp (5) Uddin, W., Li Yiqin and Lucy D. Phillips. Integrating of Remote Sensing and Geospatial Technologies for Managing Transportation Infrastructure Assets. CD Proceedings, 2 nd International Symposium on Maintenance and Rehabilitation of Pavements and Technological Control, Auburn, Alabama, July 29 August 1, (6) USGS. (7) Uddin, W. Transportation Industry Application Utilizing Airborne Laser Terrain Mapping Technology. Final Report Center for Advanced Infrastructure Technology, The University of Mississippi, February (8) Uddin, W. Evaluation of Airborne Lidar Digital Terrain Mapping for Highway Corridor Planning and Design, CD Proceedings, International Conference Pecora 15/Land Satellite Information IV ISPRS, American Society for Photogrammetry & Remote Sensing, Denver, November 10-15, (9) Turner, A. K. and Jack Hansen. Remote-Sensing and Data Capture Technologies for Transportation. Proceedings of a workshop prepared by TRB Committee A2A01 Photogrammetry, Remote Sensing, Surveying and Related Automated Systems, Transportation Research Board 82 nd Annual Meeting. Washington DC, Sunday, January 12, (10) SpaceImaging images. (11) DigitalGlobe images. (12) Momm, Henrique. Applications of Remote Sensing Terrain Data for Improved Design and 3-D Visualization of Transportation Infrastructure Assets. A Graduate Project Report, The University of Mississippi, May (13) Uddin, W. and Emad Al-Turk. Airport Obstruction Space Management Using Airborne LIDAR Three-dimensional Digital Terrain Mapping. CD Proceedings, Federal Aviation Administration Technology Transfer Conference. Atlantic City, May