SR 05:042 - Laserfiche WebLink

EXHIBIT A Scope of Work and Specifications 2005 Livermore Valley Mapping and Orthophotography Project Scope HJW will extend the relationship that has developed over the last 4 years by undertaking a project to update the mapping and orthophotographic coverage we have provided to the Livermore Valley Partners. The project will have two components: an area of high resolution orthophotos meeting 100-scale accuracy specifications with contours generated on a two-foot interval and an area of lower resolution orthophotos meeting 200-scale accuracy specifications with contours generated on a 10-foot interval. The two project components are referred to as the HighRes and LowRes areas in the attached Specifications and their extents are shown in Exhibit C following. Photography and Control Methods The new photographic materials that will be used in this update project will be consistent with the materials used in the previous projects. The HighRes area will be photographed at 1:7200 in color and controlled by a combination of Airborne GPS data collected at the time of flight, ground control points from our previous work, and newly set and surveyed ground points. The project plans call for approximately 500 exposures in 35 flight lines supported by 40 ground points. The LowRes area will be photographed at 1:24000 in color and controlled by a combination of Airborne GPS data collected at the time of flight, ground control points from our previous work, and newly set and surveyed ground points. The project plans call for approximately 40 exposures in 4 flight lines supported by 8 ground points and ties to older photography. Contour Mapping The controlled photography will be used to update and extend the terrain model that was developed in 2001 and revised partially in 2003. The terrain data generated for the City of Dublin in1995 will also be incorporated and revised. The method relies on using our softcopy compilation instruments. In the softcopy environment old data is viewed as it overlays new stereo imagery enabling the compiler to easily identify areas of change. The old data is clipped out and new data is compiled to accurately represent the changed conditions. Contours are then generated as normally and introduced into the stereo view to check for fidelity to the ground configuration. The contouring and spot elevations are converted to AutoCAD .DWG format and cut into the tiling scheme of each partner.