project, Sakals used the UAS to photograph the stream channel downstream from the dam. He used Mission Planner software to create the flight plan by defining the area that he wanted to cover, the elevation and the degree of overlap and sidelap for the pictures, which in this case was 75%. PhotoModeler provided Sakals with the capability to assemble the photos into a single 3D model and resulting orthophoto that provided a coherent visualization of the stream. Sakals saved the flight path and plans so that he can fly the drone over the stream again in the future to facilitate comparisons over time. The data from PhotoModeler can be exported to various other software packages that calculate the differences between models to easily and quickly determine what changes have occurred in the stream since his last model was created. Results over time will be evaluated to determine if changes to further developments are required.
Placer mines that excavate stream bed deposits for minerals are also sometimes a subject for Sakals to survey. In certain areas, limits are placed on the amount of disturbed ground allowed. Sakals uses PhotoModeler and UAS photography to create georectified orthophotos to quantify the disturbed area. Other staff in FLNRO’s Resource Management Division can then view the orthophotos in GIS software to assess the level of ecosystem rehabilitation and determine whether the survey area is once again a habitat for wildlife and allow the miners to continue working elsewhere.
“The combination of a drone and photogrammetric software made it possible to complete all of these projects with much higher levels of safety, cost efficiency and accuracy than could have been achieved with conventional techniques,” Sakals concluded.
For more information about PhotoModeler, contact Eos Systems Inc., 210 - 1847 West Broadway, Vancouver BC V6J 1Y6, Canada. Ph: 1.604.732.6658 or email [email protected]
Photo of a bluff requiring rock slope remediation. Part of a government remediation project, this photo will be one of many used to calculate the mesh area and other requirements.
Below: Rendered 3D surface model (right) of the bluff in previous image. The individual photos taken at the site are shown in the two images on the left. PhotoModeler surface drawing tools were used to outline the area of proposed slope mesh (green lines on surface model). The surface model with 3D lines outlining proposed slope mesh areas are imported into AutoCAD Civil 3D to calculate mesh surface areas and produce final drawings.
Oblique perspective of the canyon and the fish-obstructing rockslide created in PhotoModeler.
Two of the photographs taken from a UAV of the canyon and rockslide that were used to build the surface model and orthophoto.