Tuck Mapping Solutions of Big Stone Gap, Virginia sought the best available digital camera and position and orientation tools to provide Eagleeye with the ability to acquire exceptional vertical accuracy levels (as precise as one inch), while maintaining the flexibility to offer lesser accuracy levels as required to match client needs. Tuck demanded the reliability and full support of off-the-shelf components, while retaining the flexibility of an easily-tailored system, one that could be used for Power Utility Mapping and many other mapping applications.
The Solution
Tuck chose the Trimble DSS 322 precision digital camera with custom optics, the Applanix POS AV (position/orientation technology) specifically designed for airborne applications, and the Applanix POSTrack flight management system for eagleeye. DSS is the only medium format solution with USGS certification to produce mapping grade products. Unique to Applanix POS AV, direct georeferencing eliminates the requirement for aero-triangulation and a complete ground control survey, simplifying Tuck's operations and reducing post-mission processing time considerably.
The Trimble camera obtains 3.0" pixel resolution at 1000 feet AGL. The Inertial Measurement Unit (IMU) chosen was the Applanix 200 Hz POS AV V5 Model 410, which collects orientation data 200 times per second to provide the precise location of the sensors at the time of data acquisition. The positional accuracy of the unit is .05 - .3 meters: angular accuracy is 0.008 degrees in pitch and roll and 0.015 degrees in heading: velocity accuracy is 0.005 m/s.
The Applanix POSTrack was chosen as the navigation system, giving Tuck the Industry's leading GNSS-aided inertial direct georeferencing and advanced flight management system. It is used to plan LiDAR swaths and digital camera centers, and the data it collects is exported to the helicopter computer system for flight guidance. POSTrack ensures accuracy by directly controlling both the LiDAR data recording and the digital camera.
The Result
Tuck Mapping Solutions and eagleeye have developed an exceptional record of success in aerial mapping. Power Utility Mapping has become a major source of business for Tuck Mapping Solutions. Here is a brief summary of some of the successful missions of the eagleeye system using Applanix technology:
Duke Energy Transmission Line Survey - North and South Carolina
Tuck Mapping Solutions utilized the eagleeye mapping system to complete a LiDAR survey of approximately 125 miles of transmission lines for Duke. Some of the right-of-ways were mapped for new line construction and others for re-rating of existing lines. LiDAR data was acquired at 300 feet AGL to ensure highly accurate line, structure and ground points. Corridors were also flown at 1200 or 2000 AGL to acquire data and imagery for color stereo digital models. The lines and ground were mapped from the LiDAR data to approximately 3-inch accuracy and planimetrics were compiled from the digital imagery. Color orthos were produced for the corridors and rectified color images were also provided in PLS CADD format for the design of the lines.
Virginia Coalfield Expressway
The project consisted of approximately sixty miles of mountainous terrain that the Virginia Department of Transportaton is planning to put a four lane highway to connect Pound, VA to Beckley, WV. We flew a one mile wide corridor for the length of the project and then flew several connectors along the way. The area was very rugged and had a large number of conifer trees in the alignment. The highway department was delightfully surprised that there were no areas that had to be filled in by the field crews due to dense vegetation. When they checked the accuracy of the project, they determined that the mapping was within about .15 feet of the check survey. The corridor was flown at 500 feet AGL with the eagleeye mapping system and then was flown with a RC-30 in our Navajo aircraft with color imagery.
Route 460 Corridor
This project was a project in the eastern portion of Virginia between Petersburg and Suffolk, VA. The area is very flat and the new alignment traversed 75 miles of farmland. The corridor was flown with the eagleeye mapping system with a Riegl 560 scanner operating at 240kHz and was then flown with the RC-30 camera in the twin engine Navajo for the color imagery. We opted to use the RC-30 for the imagery because the eagleeye with the DSS 322 would have had thousands of images to work with on this large of a project. When the accuracy of the LiDAR was verified by the VDOT survey contractor, it was found that Tuck Mapping Solutions has achieved a vertical accuracy of .15 feet over the length of the project.
North Anna Nuclear Plant and Wetlands Area - Virginia
Tuck mapped Dominion's North Anna Power Plant in northern Virginia. Tuck flew over the nuclear power plant with the helicopter at 500 feet AGL. The helicopter obtained both the LiDAR data and the color digital imagery for planimetrics and orthos.
In addition to the plant site, wetland areas around North Anna Lake were identified and mapped. This was accomplished by flying the environment engineer around the 250-mile perimeter of the lake to identify areas of concern. The engineers marked the areas on quad maps and Tuck flew sixteen areas for LiDAR and photography acquisition, providing 1-foot contour and color orthos of each area. The wetlands mapping was necessary for planning future expansion.
US Air Force Bases
Tuck Mapping Solutions has mapped fifteen Air Force bases for the Geobase initiative. We generally map the entire base area plus a 1000 foot buffer. Tuck Mapping mobilizes from the ramp at the base and works with the controllers to fly the entire base area at 500 feet AGL. The bases are then flown with the RC-30 in the aircraft to produce the digital orthos. Each base has quality control surveys to verify the accuracy of the LiDAR and Tuck Mapping has averaged approximately .2 feet vertical accuracy over all the bases. Each base is supplied with a flight plan from POSTrack before the mission starts so the controllers can know exactly where the helicopter is flying on each mission. This flight plan also allows the controllers to ask our flight crew to move from one area to another to avoid military traffic.
A word from our customer
"When I began exploring the merging of a metric camera with the Riegl scanner, we began talking to Joe Hutton at Applanix due to their reputation in the industry for the IMU. We also were interested in putting the DSS camera with the Riegl scanner to have an integrated system. We decided to take the existing DSS camera system with the Applanix 410 IMU and write the software necessary to sequentially geo-reference the camera and the scanner. The Applanix staff has modified the POSPac software for both the Riegl 240 scanner and the Riegl 560 scanner for the integrated system. We can now flight plan the DSS camera and scanner and utilize one plan to acquire both imagery and point clouds. The staff at Applanix has been instrumental in the success of Tuck Mapping in this venture and we are constantly trying to find ways to improve our accuracy and also the efficiency of operations. As the technology evolves, the staff of Tuck Mapping and Applanix are working together to determine future integrated systems that will provide high quality products for the engineering marketplace." - Bobby Tuck, President of Tuck Mapping Solutions