HJW GEOSPATIAL TO PRODUCE LIDAR DIGITAL TERRAIN MODEL AND ORTHOPHOTOGRAPHY OF SAN MATEO COUNTY

Oakland, California, October 10, 2005 – HJW GeoSpatial (HJW), Inc., has been awarded a contract to produce a LiDAR digital terrain model and color orthophotos for the County of San Mateo, CA. The project is being funded by the County of San Mateo, the U.S. Geological Survey, the San Mateo County Transit District and the City/County Association of Governments of San Mateo County.

HJW will acquire roughly 500 square miles of color photography at two photo scales. Urban areas will be flown at a photo scale of 1:7200 (1”= 600’) and scanned at 2400 dpi to support the production of orthophotos with ¼’ pixel size. Rural areas will be flown at a scale of 1:15,000 (1”= 1250’) and scanned at 2500 dpi to support the production of orthophotos with ½’ pixel size. The orthophotography will meet National Map Accuracy Standards for 1”= 100’ and 1”= 200’ scale maps. The orthophotos will be manually seamed together into a mosaic and delivered in a pre-defined tiling scheme.

LiDAR data will be acquired for the entire county, and used to generate the digital terrain model which will be used for orthophoto production. HJW will classify and filter the LiDAR data in order to achieve a bare-Earth terrain model, which will be accurate enough to generate 2’ contours. In addition to using standard automated filtering procedures, HJW will employ photogrammetric methods to add a higher degree of confidence to the final product.

Prior to this project, in 2004, HJW produced 1”= 100’ color orthophotos for the City of San Mateo, and in 1997, HJW produced orthophotography for the entire County.

The U.S. Geologic Survey’s interest in this project is to acquire base data for its National Map program. The National Map will provide public domain core geographic data about the United States and its territories that other agencies can extend, enhance, and reference as they concentrate on maintaining other data that are unique to their needs. More information about this program is available at http://nationalmap.gov.