Terrestrial Photogrammetry: Development of Capabilities and Exploring Applications for Three-dimensional (3D) Measuring from Photographs
* How can scientists and engineers very accurately and quickly perform surveys and make measurements using only digital photographs?
* How can the gradation and size of sediments in a river bed be measured to sub-millimeter accuracy for fluvial geomorphology studies using only digital images?
* How can infrastructure like bridges be surveyed to sub-millimeter accuracy in a fraction of the time that conventional surveys would require?
* How will surveying be revolutionized by digital photogrammetry as the new software becomes faster and simpler to use?
* How can Reclamation take advantage of this incredible technology and establish a multi-discipline photogrammetry analysis team to speed up and improve the quality of data acquisition?
* How can this information be disseminated throughout Reclamation so all offices have the opportunity to understand and use this new technology?
* How can the safety risks associated with surveying in steep terrain or dangerous areas be eliminated?
Need and Benefit
In the last two years, Reclamation's Dam Safety Office has invested over $200,000 to develop digital photogrammetry capabilities for measuring the orientation of geologic structure in steep areas downstream of concrete dams and for precisely measuring the cracks in concrete dams without the need for expensive surveys or climb teams. The ability to develop topography using photogrammetry is also being studied. The geologic aspect was successfully completed in December 2004. We now can do more accurately in a few days for minimal cost what used to take weeks of work with a climb team. The topographic and crack mapping aspect of the current research is scheduled for completion by the end of fiscal year (FY) 2004. This research has been remarkably successful beyond any of the original goals and has lead to the possibility of applying this technology to more diverse problems and programs.
We are developing the capability to produce 3D images and topography using readily obtained photographs. Through the ongoing dam safety research, investments in hardware and software have allowed advancements of this revolutionary capability not possible without research commitments. Many partnerships have been developed, includin the Bureau of Land Management, the Colorado School of Mines, and the Commonwealth Scientific and Industrial Research Organization (CSIRO) in Australia . These new capabilities have been shared with some of Reclamation through the construction and geologic conferences. Several projects have been successfully completed (East Canyon Dam, Dulce Dam and Crystal Dam), and major safety issues during surveying were completely eliminated. The commitment to establish photogrammetry capabilities to perform dam safety work is successfully nearing completion.
The potential for applying this technology throughout Reclamation to countless other applications outside of the dam safety function is enormous and limited only by our imagination. Funding additional research would allow further development of the technology by researching better software that is being developed quickly, directly integrating the photogrammetry terrain models with computer-aided design and drafting (CADD) and geographical information systems (GIS). A new partnership with the Technical Service Center (TSC)'s Remote Sensing Group and continuing partnerships with the Photogrammetry group at the Bureau of Indian Affairs (BIA) along with software engineers at CSIRO and "PhotoModeler" and Reclamation's Regional Offices would allow this technology to perform work such as fast 3D modeling of bridges and other infrastructure, fast modeling of powerplants or pumping plants to measure and verify construction accuracy, fast modeling and measurement of streambed sediment sizes to facilitate fluvial geomorphology data needs, rapid measurements of borrow pits or borrow stock piles, collection of 3D images for any structure foundations, rapid collection of geologic information underground in tunnels, deformation of walls and floors, etc.
In the next five years, this new technology will completely revolutionize the way surveys are performed. It is a common belief in the industry that photogrammetry will render many or most laser survey operations obsolete due to the increased accuracy, speed of acquisition, and the shear volume of data that can now be collected with simple photos. Reclamation cannot afford to ignore the potential for this technology to save time and money. Just as importantly is defining limitations of this tool and how verification and accuracy decisions and planning are an essential element of photogrammetry.
The goal of this research is to educate Reclamation and spread the technology within and outside the organization by expanding the capabilities and communicating and demonstrating its potential.
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