Low Elevation Aerial Photography (LEAP)

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Low elevation aerial photography (LEAP) is a cost-effective technique for obtaining high resolution, digital and georeferenced aerial photographs using unmanned aircraft systems (UAS) and other compact airborne devices ideal for repeat mapping of physical and biological features in small reaches.

How does it work?
Georeferenced photographs are systematically taken with a remote-controlled unmanned aircraft system (UAS; or “drone”) or manually controlled balloon device at an altitude less than 150 m. All field operations are under the direct supervision of one of our FAA-certified pilots. Images are then digitally corrected in a photogrammetric software package (e.g., Pix4D Mapper or Agisoft PhotoScan) using surveyed ground control points. The corrected imagery is processed as an orthomosaic basemap and 3D topographic surface compatible in GIS and engineering-design workspaces. The entire workflow entails rapid field mobilization, automated flight paths, need for few ground control points, and streamlined data processing and quality control.

Our LEAP program is ideally suited for a wide range of applications where high-resolution, spatially accurate planform imagery and 3D surfaces are required for detailed field mapping, analysis of environmental conditions, and creation of a time series of imagery to  evaluate trends. The methodology is repeatable and cost-effective, and is compatible with all spatial analysis and engineering design typically done in ArcGIS and AutoCAD.


Low elevation aerial photography is a cost-effective way to obtain high resolution, digital base maps in areas where traditional aerial photography is not possible.View the gallery cialis online


Ian Pryor
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Work Products

Download the LEAP Fact Sheet [pdf]
Download the poster [pdf, 3M]


Assessing success of large wood and boulder placement in Rock Creek, OR

Population modeling based on field habitat conditions determined that enhancing habitat in Rock Creek (a tributary of the Umpqua River) would provide greater benefit to the overall salmon population than constructing fish passage over a dam and opening up 1.4 miles of historically available habitat. To assess spawning gravel retention behind placed large woody debris and boulders within Rock Creek, we used LEAP to photograph the reach where boulders were placed.

Fish habitat assessment and flow recommendations for the South Fork American River, CA

LEAP was used on the South Fork American River to provide base maps for field delineation of fish habitat parameters such as depth and velocity. The data were then combined using GIS to create high-resolution, site-specific maps of fish habitat in the river.