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TECHNOTES The geotechnologies industry has done an excellent job of satisfying the demand from end-users for enterprise-wide access to GIS applications. Today, users in nearly every department within an organization can perform GIS queries and functions from their computer desktops. Enterprise-wide access, however, has traditionally focused only on GIS applications, excluding geospatial data and its production...until now.
Z/I Imaging of Huntsville, Ala., has taken the lead in attaching the "enterprise-wide" moniker to the entire sequence of geospatial data production and use. It has accomplished this by developing TerraShare, a system that manages and provides open access to terabytes of digital imagery through its life cycle, from acquisition and exploitation to storage and distribution. TerraShare is a modular, client-server system created for Earth-imaging professionals to facilitate the management of multiple types of imagery and terrain data throughout the production process. In developing this system, Z/I Imaging has also expanded the geospatial data access concept into the realm of distribution by putting data sets in the hands of desktop-based end-users in Windows Explorer, or in their CAD and GIS applications. "While other products simply serve image data to end-users, TerraShare completely manages image data in its production and distribution," said Joe Bima, the America’s program manager for enterprise solutions at Z/I Imaging. The geospatial data handled by TerraShare includes scanned aerial and digital satellite imagery, and also related raster data sets such as digital terrain models and digitized raster graphics. In addition to the data sets themselves, TerraShare maintains access to related metadata databases in a single, integrated environment. From a practical perspective, TerraShare improves efficiency and communications within organizations that process imagery. Any manager, supervisor or technician on a local network can access the imagery and see precisely where it is in the production cycle. Even the end-users who will eventually receive the data can dial into the system to check its status and perform online quality control. "TerraShare creates a common working environment where anyone with approved access can interact with the image data without duplicating the data during production or distribution," said Bima. Aside from the obvious rewards of greater efficiency, TerraShare customers say the absence of duplicating files has the greatest impact on their bottom line. TerraShare drastically reduces the amount of file space needed to store digital data. And regardless of where imagery is eventually archived, TerraShare maintains instant access to data files, even in multiple locations. "A TerraShare user never wastes time looking for an image or the metadata that goes with it," said Bima. "All imagery and related files are accessible within seconds." Production Shops First to Adopt Storing and managing digital data is a major problem for photogrammetric production houses today, primarily due to the enormous size of the files involved. Predictably, photogrammetric services firms are among the first to embrace TerraShare technology, because it enables them to enhance capacity and efficiency without adding seats or buying extra tape drives. "The bottom line is that TerraShare enables organizations to move data through their production streams more quickly," said Bima. Sanborn Colorado LLC is a leading GIS mapping firm based in Colorado Springs. At any given time, it has dozens of photogrammetric processing projects in the works, with all production being performed onsite. Sanborn scans an estimated 30,000 high-resolution aerial images every year. It was the first U.S. company to deploy the full TerraShare system. "The biggest problems we face are the number of image files and their huge size, not to mention related metadata files," said Trevor Greening, vice president of engineering. Greening says that many processing firms encounter the same challenge as Sanborn. They have so many projects going at once, each involving terabytes of data and often lasting many months, that it becomes virtually impossible to keep all the data live throughout the project’s duration. And if it is not kept live, precious time is spent searching for and retrieving files from disk storage. "Duplicating files wastes disk space and creates a problem with data integrity," said Greening. "With so many file copies floating around, it’s hard to tell which is the most up to date, and people sometimes work on old versions." Prior to purchasing TerraShare, Sanborn performed a return-on-investment calculation and concluded that the system would pay for itself in short order. Sanborn uses a Network Attached Storage (NAS) device equipped with an array of hard drives. It plugs directly into the company’s network using a 2GB connector. "Even with this capacity we figure that, prior to deploying TerraShare, someone in our organization would spend 15 to 20 minutes to find a file, access it, and then re-store it," said Greening. "In a project’s lifespan, we access every file three times, which means 45 to 60 minutes consumed in total. Now multiply that by 30,000 files and you see the time that data management consumes throughout a year." Z/I Imaging installed TerraShare to run on top of Sanborn’s Microsoft SQL Server. Through this database server, TerraShare automatically keeps track of where each image file and its related metadata are stored. When a user wants to access an image, whether it is live on the server or stored in the NAS, TerraShare retrieves it immediately and displays it on the Microsoft Explorer interface. "Everybody is always accessing the same, most current, image file," said Greening. "This is a massive benefit for us." What is perhaps even more beneficial, technicians in Sanborn’s processing division can now switch back and forth seamlessly between projects. Since no files are kept on their machines, they no longer have to wait to purge old files and upload new ones. Their efficiency has been substantially increased. How TerraShare Works The core TerraShare product is client-server software developed to operate in a single interface environment — Microsoft Windows Explorer. Z/I Imaging chose the Explorer interface because it is easy to use and provides a consistent dynamic view of data that is understandable to both production technicians and back-office users. TerraShare operates on top of a standard OLE DB provider database such as Oracle 8i or Microsoft SQL Server, and it draws all image data together into a seamless, distributed network environment from one or more databases. This automatically tracks image data as it moves through the enterprise. Physical transfer of data files from one machine to another is eliminated. Directly out of the box, TerraShare provides several levels of user categories; each has its own defined privileges for viewing and changing image data. These user levels can also be customized to meet the needs of different organizations. The overall objective of setting user levels is to build security into the system. During production, image data can progress through a variety of processing systems. By using a standard Microsoft architecture, TerraShare is able to provide access to any of the common GIS applications or photogrammetric imaging systems, so long as they also utilize an open architecture. Such systems are called "TerraShare Aware." Many geospatial software packages written today are based on Microsoft standards. For those that are not, Z/I Imaging has created a TerraShare Software Development Kit (SDK). This allows users to modify existing photogrammetric or GIS software so that application data can be written to the TerraShare repository. Creating a Modular Environment "We treat each TerraShare deployment as a custom installation," said Bima. "Depending on the needs of the organization, whether it is an image producer or user, we customize TerraShare with appropriate modules to server the customer’s needs." In addition to the core TerraShare product and the TerraShare SDK, Z/I Imaging has introduced three modules to enhance the TerraShare environment for specific user groups. TerraShare Production Manager is geared specifically toward photogrammetric production shops. It helps manage terabytes of geospatial data throughout the processing workflow by interfacing directly with Z/I Imaging’s ImageStation products. This module tracks images, stereo models and elevation data dynamically in the production environment. TerraShare e-geo is an e-commerce solution that enables users to manage, display, distribute and sell large volumes of raster data over the Internet. e-geo allows potential customers to pan and zoom through imagery and inspect its metadata online. When incorporated into the TerraShare cycle, e-commerce becomes another phase of production that can be managed through the client-server environment. TerraShare Ortho Manager is a powerful application that enables a TerraShare user to collect all ortho-images, seamlessly mosaic them to cover the entire project area, and then display this mosaic as a single image in a desktop CAD or GIS application. The end-user sees a single image while, behind the scene, Ortho Manager automatically manages the integration and display of data. Expanding the Enterprise "Enterprise-wide access has always been about improved efficiency, and what we have done with TerraShare is extend that efficiency to the image data production and distribution processes," said Bima. This benefits production houses and end-user organizations by allowing them to take better advantage of the investment they have already made in infrastructure and processing systems, he explained. To get more out of their data, organizations no longer need to spend a lot of money on new tape drives and desktop computers. "TerraShare makes the imagery workflow more effective without adding new machines," said Bima. "It’s for organizations that want their data now." About the Author: |
TerraShare
operates on top of a standard OLE DB provider database such as Oracle
8i or Microsoft SQL Server, and it draws all image data together into
a seamless, distributed network environment from one or more databases.