Customer Stories

California's San Luis Obispo County has attracted thousands of newcomers in recent years, and that influx has strained its housing market. One ambitious development project aims to help ease that pressure. In support of this vision, a local photogrammetry company has been using advanced photogrammetry software to deliver detailed, foundational 3D maps upon which to build the new community. overview Location CALIFORNIA TRANSFORMING THE WAY THE WORLD WORKS TRANSFORMING THE WAY THE WORLD WORKS Given San Luis Obispo's (SLO) urban growth, the state of California expects the city of SLO to build 3,508 housing units by 2028 to meet estimated demands. In May 2019, construction began on San Luis Ranch (SLR), a mix of 580 multifamily and single-family homes intertwined with parks, open space and agricultural farmland. Central Coast Aerial Mapping (CCAM), has been offering digital orthophotography and photogrammetric mapping services since 1977 and has earned a unique reputation for producing superior, 3D-stereo-based maps efficiently and cost effectively. Given its reputation and strong working relationships in the AEC and surveying markets, the prime development contractor chose CCAM to provide the critical 3D data for the SLR project. CCAM needed to produce two 3D topographic maps vertically accurate to 0.1 foot, which included 1-foot contours and planimetric features such as roads, fences and vegetation. One topographic map would cover 441 acres and a second map would detail a 140-acre section planned for grading. CCAM also needed to create two orthomosaics at 0.2 feet accuracy. AN EFFICIENT PROCESS Prior to the aerial work, a crew set nine ground control points (GCPs) and established five checkpoints They then flew the area of interest (AOI) with a digital photogrammetric camera. They captured 23 photos at a ground sample distance of 3 cm. The processed images, the GCPs and the center coordinates of each photo were imported into Trimble Inpho's MATCH-AT georeferencing module to automatically triangulate the images. "Before we used MATCH-AT, we'd have to find common image points and tie them together manually, which could take days," said Robert Lafica, certified photogrammetrist and CCAM's owner. "Inpho triangulated this project in 20 minutes."

• Cover