Applications

Background

Technology 1: SI-SFAP (Spatial Information-Small Format Aerial Photography) SI-SFAP, specifically refers to the integrated applications of high-resolution (sub-inch) small format aerial videography/photography with commercial off-the-shelf GIS application software for highway bridge system monitoring. SI-SFAP can enhance existing inspection requirements of highway systems and provide long-term safety performance/structural performance improvements. In order to capture high-resolution aerial imaging of highway bridges and pavements at low costs, SFAP aerial photographs are typically taken from a much lower altitude (approx. 1,000 ft) such that higher resolution digital images can be captured for smaller areas. Since these photos are from a lower altitude and only small areas of coverage are needed, the orthogonal rectification of the imagery was not performed, nor deemed necessary. The resolution of the digital images is defined as the ratio of the actual physical dimension of the sensor pixel to the physical dimension of the object in the photo. The SI-SFAP technology is an integration of low-flying aerial photography, coupled with high definition video and photo recording instrumentation, onboard GPS systems, and SI-based information management systems (or, GIS) such as Google Earth ® and ArcReader ®. The integrated solution can provide sub-inch resolution photo and video imagery that allows highway engineers to manage their assets and monitor construction progress. Figure 1 shows progress of bridge construction monitored using SI-SFAP technology, which includes the use of a Cessna 210 Airplane and a Canon 5D Digital Single Lens Reflex (DSLR) camera. The aerial photos show detailed, georeferenced and time-stamped documentation of the construction project in North Carolina, including the site condition and construction progress at a resolution of 1”.

Figure 1 SFAP Images of Bridge Demolition and Construction

Using SFAP, special considerations including punching shear, corner cracking, spalling, pot holes, and other damage of the bridge, can also be identified easily. Another important feature of the SFAP method is the potential of quantifying bridge relative movements by measuring expansion joint openings. Current inspection reporting does not require exact measurements of expansion joints. As a result, no documentation of bridge movements has been included in the national bridge inventory database. However, using periodic, high-resolution aerial photography such as SFAP, it is possible to establish temporal records of bridge joint movements.

Bridge Health Monitoring / Data Visualization (IRSV)

IRSV 2.0, a web-based interactive visual analytics system for bridge management.

Welcome to IRSV 2.0, a web-based interactive visual analtyics system for bridge managment. IRSV is a prototype Integrated Remote Sensing and Visualization system. Our system is designed under the scope of our multi-year research project on developing and validating Commercial Remote Sensing (CRS) applications that can enhance current bridge management systems (BMS). A longer-range objective is to enable the IRSV components to be integrated into PONTIS and other state and local BMS applications. Full deplyment of IRSV will contain a high resolution visual database using, in part, on-site bridge inspection data. Additional data that is not included in semi-annual bridge inspections includes LiDAR imaging, sub-inch aerial photography, and Infrared images. Partners in this first phase research project have included the City of Charlotte DOT and the North Carolina DOT. The multi-disciplinary research team includes the UNC Charlotte Center for Transportation Policy Studies (lead), the Charlotte Visualization Center, ImageCat, Inc., Boyle Consulting Engineers PLLC, and Dr. C. Michael Walton, P.E. This project is supported by a Cooperative Agreement with the U.S. Department of Transportation, Research and Innovative Technology Administration.

IRSV, the web-based visual analytics system is still an on-going project that is conducted by students and researchers in both civil engineering and computer science departments of UNC Charlotte. The current vernilla version of IRSV only presents basic functions, such as data exploration, view coordination and basic annotation. Higher functions as ‘evidence collection’, ‘analytical reporting’ and ‘collaboration’ are disabled for stability purposes. With future updates, IRSV will re-enable this functions and present to the public with a more comprehensive working environment.

Screenshot of the application:

IRSV 2.0

‘WorkSpace’: is the same concept as a ‘desktop’ for a windows/Macintosh computer. However, the novel design of IRSV allows you to create multiple workspaces at one location. So you can start different analytical processes based upon the needs. In a workspace, you can see multiple coordinated visualizations. You can ‘maximize’ or ‘minimize’ individual workspace by clicking corresponding icons on its upper right corner. Workspace can be collective as evidence through dragging it onto the ‘orange drop box’ to the right on the screen.

Example of an IRSV 2.0 Workspace

Credits

IRSV is implemented by Xiaoyu Wang (viztang@gmail.com) at Charlotte Visualization Center. The visaul analytics framework IRSV resides on is an on-going research between Xiaoyu Wang and Dr. William Ribarsky. Dengsong Shi has contribute tremendously in the development process.

Acknowledgements

This project is supported by grant number DTOS59-07-H-0005 from the United States Department of Transportation (USDOT), Research and Innovative Technology Administration (RITA). The views, opinions, findings and conclusions reflected in this publication are the responsibility of the authors only and do not represent the official policy or position of the USDOT, RITA, or any State or other entity. The authors also would like to acknowledge the guidance and contributions of Mr. Caesar Singh, the Program Manager at USDOT; and the technical assistance of Dr. Moy Biswas of the North Carolina DOT (NCDOT), Mr. Garland Haywood of NCDOT Division 10, and Mr. Jimmy Rhyne of Charlotte DOT.

BridgeLocator

Locate bridges near you in the United States using your location obtained from GPS or Wifi (Database contains thousands of bridges directly from the NBI – National Bridge Inventory). Get driving directions to the bridge from your current location and see a satellite view of it. Save bridges to a favorites list (accessed by pressing the Settings key) so you can come back to the bridge later. If available, see detailed inspection data for the bridge (currently only for bridges in North Carolina).