HJW GeoSpatial

HJW GeoSpatial


Since its founding in 1949, HJW GeoSpatial has provided precision mapping solutions for thousands of projects ranging in size from a few acres to many thousands of square miles. HJW’s experience lends itself to both conventional and innovative approaches to project design, with full attention to detail and end-product quality. Even a relatively small project may involve multiple technologies, coordination of flight and ground operations, and a well-defined sequence of production steps which together constitute the workflow.

Beyond traditional operations with film-based aerial photography, the range of services now offered by HJW GeoSpatial includes LiDAR processing and analysis, fully-digital map production based on digital aerial imagery, and services based on the highest-resolution satellite imagery from such providers as GeoEye. HJW operates its own aircraft using the UltraCamX large-format digital mapping camera to collect the best in metric aerial imagery for mapping purposes.

Digital Camera Operations

In the last two years, HJW GeoSpatial has transformed its IT infrastructure to accommodate the latest in fully-digital photogrammetric production workflows. In 2008, HJW logged up to 100,000 images with its Vexcel UltraCamX large-format digital mapping camera system, undertaking major projects across the western United States. The UltraCamX is designed to provide the highest quality imagery over a wide range of mapping scales, uses and applications. For large projects, the digital imaging system has largely replaced the film camera as the means to acquire high quality imagery. In addition, the use of a fully-digital approach to photogrammetric production offers the most flexibility in delivered products.

HJW’s digital camera is used routinely for projects requiring imagery between 1” and 18” ground sample distance (GSD). Several thousands of square miles of coverage collected during 2008 include such highlights as the new California Academy of Sciences in San Francisco and Torrey Pines Golf Course in La Jolla, San Diego, and local and regional coverage over dozens of urban centers where the best in image quality was required.

Mapping the Lower Colorado River

During 2008, HJW GeoSpatial mapped approximately 220 linear miles of the Lower Colorado River, from Laughlin, Nevada south to the Mexican border, in support of work for the Bureau of Reclamation. The project limits varied according to the river characteristics, but in some cases was as much as two miles in width along the river corridor. In support of the project, HJW flew 1,320 exposures at 1:7,200 photo scale. Aerial triangulation was performed using airborne GPS/IMU and approximately 80 ground control points provided by Tetra Tech of Arizona. HJW collected DTM to support 2’ contour production and 6” pixel color orthoimagery of the project. Additionally, Sea Surveyor, working under contract to HJW, collected hydrographic soundings at 200’ intervals for key locations along the river. The end product was an integration of the hydrographic survey data with the photogrammetric terrain data, represented with 2’ contours. Prior to this project, the project area had not undergone such a comprehensive and accurate survey.

These projects reflect the diversity in the work of HJW GeoSpatial. Highly-detailed map content, innovative solutions to unique mapping challenges, providing the geospatial foundation for critical operations and decision support, all part of the daily activities of the HJW GeoSpatial team.

» Back to our Aerial Mapping March 2009 Issue

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