Using woodland data

Grounds, parks, and roadside managers frequently seek to identify the number of species, maturity, and health of trees in their city or county. Feature extraction provides height, crown, and canopy size of individual trees, as well as green space area within a city block, a region within a city or county, or an entire service area.

Forestry technicians use the same data to evaluate the condition of the nation’s forests.

Data for this purpose is collected during peak growth season to capture trees at their maximum canopies.

Another potential application: Vernal pool identification.

Using solar-potential data

The objective of feature extraction for solar-potential mapping is to create the best possible estimate of usable rooftop area for receiving maximum incoming solar radiation throughout a city or county.

Multiple datasets are collected throughout the year to determine the azimuth of the sun and its relationship to the angle/pitch of rooftops and to identify potential obstructions to sunlight throughout each month. The extraction process approximates the true shapes and positions of buildings in the target region to identify the 3-D boundaries of each individual roof or surface plane.

Technicians use this data to calculate the energy potential of roof surface areas, and make this information available through publicly accessible solar-potential maps that connect residents to qualified solar panel installers.

Another potential application: Shingle area for roofers. The availability of roof area data helps roofers more easily calculate shingle requirements and provide estimates.

Remote sensing technology has quickly evolved from satellite-quality data acquisition to integrated aerial systems with improving equipment and software automation techniques. Given their lower and slower flight capabilities and fully integrated sensing equipment, unmanned aerial systems promise to further improve the accuracy and ease of data collection in the near future.

Brian Stevens, CP, SP ( is Project Manager for Woolpert Geospatial Services (, Columbus, Ohio.