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Masspoints and breaklines will be extracted in the quantities and locations needed to achieve the most accurate possible representation of the ground surface for production of contours and orthophoto production, if needed. Bridges and overpasses will be correctly modeled in 3D. Contours will be generated flom the DTM's using Intergraph Siteworks and displayed on the graphics screen of a digital photogrammetric workstation. The operator checks the contour set by viewing it in 3D with digital aerial imagery in the background. Line smoothing programs are used where appropriate to enhance aesthetic quality of the contour strings. Every index contour will be labeled. 51 50 E. Hunter Ave. 8 Anaheim, CA 92807 (71 4) 777-8877 alanfrank@johnson-frank.com FAX: (71 4) 777-1 641 Johnson-Frank & Associates, Inc. On-Call Aerial Mapping & Surveying Services City of Santa Ana Digital Planimetric Mapping This task involves extraction and processing of planimetric features from the aerial photography using interactive photogrammetric techniques. Data flom field edits will be integrated at this stage as well. The photogrammetric technicians will digitize all of the planimetric features desired by the City into a MicroStation design (.DGN) file using digital mapping software. Common features are grouped together and placed on predetermined levels in accordance with the City's CADD specification, and assigned their distinguishing lineweights, linestyles and colors. The planimetric files will be divided into sheets as desired by the City, and carefully reviewed by the QC Technicians for correctness, completeness, and aesthetic quality. The files will also be checked for full compliance with the City's CADD specification. QC checks will be performed with digital imagery in the background, and the planimetric data superimposed, making any missing or incorrectly digitized features readily apparent. Checkplots will be produced as a final step in the QC process. The preliminary file sets will be written to CD-ROM disks for delivery to the City, together with a set of checkplots. Upon receiving approval from the City, field crews will be mobilized to perform field edits, cross-sections, supplemental DTM data collection, and any other survey tasks desired by the City. Total station instrumentation and data collectors will be used for this task. Upon completion of the field surveys, the data collectors will be downloaded, the data processed, and integrated into the MicroStation files with the photogrammetrically captured information. Following final QC checks, the completed MicroStation files will be written to CD-ROM disks for delivery to the City, together with a set of hardcopy plots. Orthorectification Zo 25K-22