PE and RS PUBLIC November 2011 : Page-1079Mississippi River Alluvial Floodplain, Mississippi – The Delta (USACE) The U.S. Army Corps of Engineers has been leading the way in developing lidar data for areas of need for fl ood protection, levee management, and fl ood control structures, as well as coastal areas within their jurisdiction. The Corps also leads the way in developing lidar technologies for advanced data acquisition. The Vicksburg District Corps acquired lidar data and updated ortho photos for the area commonly called “The Delta”. This area is the Mississippi River Alluvial Floodplain in the state of Mississippi and is an area of both historical and recent severe fl ooding. The area covers many counties in Mississippi and the lidar dataset required over 11,000 tiles (at 5000 × 5000 feet per tile) to cover the project area. The broad geographic extent of the Delta (Figure 9), the mostly fl at-lying terrain, and the complex nature of the stream networks, waterbodies, oxbow lakes, levees, and fl ood control structures created challenges in data collec-tion and processing. Projects such as this lidar project for “The Delta” will provide data and derived products of unprecedented accuracy and quality that will strengthen capabilities to plan infrastructure and to help protect our nation’s resources and population from the potentially disastrous impacts of fl ooding and other natural disasters. Figure 9. View of elevation data and absolute accuracy verifi cation testing of LAS data by Fundamental Vertical Accuracy for quantifying accuracy to the 95 percent confi dence level. Conclusions New lidar guidelines and specifi cations imply that incremental products must be verifi ed to ensure the accuracy, quality, com-pliance, and completeness of fi nal products. The implication of incremental product verifi cation makes apparent the need for a set of best practices, not just for verifying fi nal products, but for verifying products developed across the lidar project life cycle. Incremental product verifi cation and best practices introduce an opportunity to transform industry practices for delivery and acceptance of products. Key to the transforma-tion of industry practices would be the defi nition of specifi c interim deliverables defi ned as project milestones as well as best practices and mechanisms for engaging the producer and customer in “real time” verifi cation of incremental products as data fl ow through the project. Acceptance of incremental products opens the door to partial payment of project fees for partial completion of project deliverables. This transformation would improve project and product visibility and management capabilities for customers while improving data producers’ capabilities to improve cash fl ow during lengthy and cost-intensive lidar projects at the expense of verifying and delivering incremental products. The sum of these factors should have the cumulative effects of improving projects and products, providing a consistent set of best practices, and advancing industry and mapping community practices; ultimately leading to improvement in lidar data and derived mapping product quality, accuracy, and cost-benefi ts. Figure 7. View of Michigan project elevation data and absolute accuracy verifi cation testing of LAS as well as DEM data by Fundamental Vertical Accuracy for quantifying accuracy to the 95 percent confi dence level. Author Charles O'Hara, Spatial Information Solution, Inc. Spatial Information Solution, Inc. (SIS) was formed as a spin-out from Mississippi State University with a focus on the commercialization of software technologies for map data accuracy and quality verifi cation. Accuracy Analyst and Topo Analyst are an automated QA software solution for orthophoto verifi cation and a software solution for automated accuracy verifi cation and quality assurance of elevation data respectively. Figure 8. View of Tuck Mapping DOT demonstration project elevation data and absolute accuracy verifi cation testing of LAS data by Fundamental Ver-tical Accuracy for quantifying accuracy to the 95 percent confi dence level. cgohara@spatialis.com http://www.spatialis.com/ Photogrammetric engineering & remote SenSing November 2011 1079 Publication List Using a screen reader? Click Here |
