GIS Gives Port a Common Operating Picture Continued from page 31 PortGIS Explorer is the most widely used GIS Web application. It gives staff access to high-resolution aerial photos and TideLands Mapbook. GIS analyst Ari Isaak (left) and GIS coordinator Malcolm Meikle (right) review updates to the Port of San Diego's online GIS portal. Ari Isaak, a GIS analyst for the San Diego District Port. Creating an enterprise GIS has driven the implementation of data and file structure standards in the engineering department so CAD data can be seamlessly displayed and analyzed through the wide variety of ArcGIS Server clients. Web-based clients, accessible to all port employees, provide new tools for understanding the infrastructure the port manages and maintains. Users in engineering management and general services and asset managers in the real estate department also use these tools. Moving data from CAD to GIS, CAD operators must follow naming conventions for drawings, layers, objects, and attribute blocks. The port adopted the United States National CAD Standard—which is used by organizations throughout the United States for exchanging building design and construction data—as a guideline for its own CAD data standards. The Department of Homeland Security Geospatial Data Model is used as a data model guide. All scanned paper plat and record drawings are accessed by an intermediate table that contains relevant information about the documents that are stored in the geodatabase. Standardizing layer naming conventions for new drawings, as well as the creation of a master CAD drawing, means that engineering staff update those files instead of storing these drawings on local drives. This ensures that every department can understand and use GIS data. This has made attribution much easier, and CAD operators no longer need to guess how to describe features in the drawings. Just Add Imagery Another advantage of this system is the ability to view and use imagery in the CAD stations using the ArcGIS for AutoCAD tool. In the past, when engineers added TIFF images to AutoCAD—one at a time—the draw time was lengthy. If a drawing spanned more than one image, 32 ArcUser Winter 2010 each image had to be loaded separately. This process was time consuming and frustrating for operators. "CAD designers love ArcGIS for AutoCAD if for no other reason than they finally have access to very high-resolution aerial [photos] quickly," said Isaak. The port has two sources for imagery: .3-meter resolution aerial photographs from ArcGIS Online and 4-inch pixel resolution aerial photos flown in April 2009 by the port. The 4-inch resolution photos are used for quality control and as a source for creating new data. To use the aerials for these purposes, engineers must follow strict standards and use the same coordinate system employed by the GIS operators. This simple change has been advantageous. Now, drawings can be viewed in the correct geographic space even if an image is not used as a backdrop. Drawings can also be located by performing a spatial search rather than by the name of a drawing. Now drawings can be used for more than one project. Previously, drawings had to be copied and pasted into work projects. These changes have cut down on the errors inherent in copying data and the amount of file space needed to store the drawings. Because the source data is managed in the GIS database, it can be used more than once. Now, everyone in the port is using the most accurate data. Web-Based Enterprise GIS throughout the Port "By using geographic data and systems, the port is able to use geography as the common factor to bring together data that otherwise is difficult to integrate," said Meikle. In 2007, when ArcGIS was adopted, the GIS group moved from the real estate to the information technology (IT) department. This allowed IT to manage and disseminate GIS data throughout the port. Access to the GIS data and system has empowered the port's employees to integrate their own independently developed workflows for managing spatial data and www.esri.com