involved rewiring the Reston and Menlo Park facilities, installing more than 5,000 telephones, training employees to use the system, and testing to ensure that the system fulfilled the needs of its users. Features available on the system include speed dialing, call forwarding, automatic call back, call pickup, call waiting, phone mail, and conference calling. The standard black telephones were replaced by multifunction touch-tone telephones, but the more striking change took place in the communication center, where electronic switches replaced mechanical relays.

The new system is a fully automatic digital telephone switching system that has access to the Federal Telecommunications System (FTS), Division service centers, and GEONET, the Department of the Interior's nationwide data communications network. GEONET provides ready access to more than 100 Geological Survey computers throughout the United States and to several public networks. GEONET links computers of the Geological Survey with those operated by the Fish and Wildlife Service, the National Park Service, the Minerals Management Service, the Bureau of Mines, the Bureau of Reclamation, and the Department's Office of the Solicitor. The network is also used by the Bureau of Land Management and the Office of Surface Mining.

More than 4,000 people use GEONET each month, initiating a quarter of a million computer sessions, transmitting about 2 billion characters of data, and logging approximately 46,000 hours of network time.

GEONET operation is monitored around the clock by a vendor-owned, vendoroperated network control center, which is responsible for keeping GEONET in an operational status 24 hours a day, 7 days a week. That responsibility includes maintaining GEONET hardware and coordinating with local telephone companies to keep telephone circuits in an operating condition.

Va.; installation of a similar system was begun in Menlo Park, Calif.; and a nationwide communications network called GEONET was acquired. These changes in the telecommunications system have significantly affected the way in which the Geological Survey performs its mission.

Installation of the new telephone system, called the computerized branch exchange,

Reston Service Center By Theodore J. Herrman and Thomas J. Faulds

The Information Systems Division Service Center in Reston, Va., provides large-scale computing resources for the scientific, technical, and administrative staffs of the Geo

logical Survey. Through GEONET, the Department of the Interior's nationwide data communications network, users can access two Amdahl mainframe computers, an IBM mainframe computer, and a VAX minicomputer, all of which are installed at the Reston Service Center. Newly constructed in 1985, this facility provides a modern, secure location for some of the Geological Survey's shared computers, communications equipment, and other computers serving many of the program needs of the Geological Survey and other Department bureaus.

The Service Center provides up-to-date protection for the electronic equipment. A sophisticated uninterruptible power supply isolates the computers and communications system from power surges or failures. Diesel generators activate during long power failures to ensure stable, continuous operation. During fiscal year 1986, the Amdahl computers were upgraded and are now controlled by new operating systems. Fiber-optic cables connect the computers to high-speed laser printers that can produce quality graphics, and modern magnetic disk technology provides 50 billion bytes of online storage. Comprehensive security software protects the computers and the data from unauthorized access; the tape library is automatically controlled to provide protection against accidental erasure; and new communications links permit easy and reliable transmission of data between mainframes and microcomputers. Large volumes of printed output can be directed to highspeed printers, while higher quality printing can be handled by laser printers.

Contributions to Geographic Information Systems

By Richard A. MacDonald

A geographic information system is an integrated set of computer hardware and software that is used to acquire, store, analyze, and display digital spatial data. The Division assisted the program Divisions in geographic information system activities and undertook some initiatives of its own in fiscal year 1986. Division personnel were trained to use the geographic information

system used in most of the Geological Survey, so that they could better assist in the computer science aspects of that system. A prototype geographic information system, funded by the Geological Survey and using artificial intelligence methods, was delivered by the University of California, Santa Barbara, to the Geological Survey for further refinement and use. This software resides on the Division's VAX minicomputer. The Division is expanding the system's graphics capabilities, writing routines to interface with other geographic information systems, incorporating expert capabilities, and extending the query language used by the system.

The Division investigated the use of general-purpose microcomputers in geographic information systems. A low-cost image analysis and digitizing work station was assembled from hardware and software components generally available in the marketplace. Principal elements of the system were a microcomputer having an expansion interface, a digitizing tablet, a video scanner, a high-resolution color monitor, and software for image enhancement and analysis.

Because geographic information systems perform many calculations, they function. poorly on conventional computer systems. The Division investigated the use of concurrent processors as possible candidates for processing geographic information system data. During fiscal year 1986, Division employees received training and spent time processing a Geological Survey system on a parallel processor. Tests indicated that this technology is promising for use in geographic information systems.

Working with microcomputers and various software systems led to investigating data exchange capabilities among software packages and among data bases. Translation programs were developed to allow transfer of data from one processing system to another. One set of programs translates data from the source system to a common file format, while a second set translates data to a target system format from the common file format.

The Division continued to research new technologies to support the massive storage requirements of geographic information systems. Two promising systems using optical storage devices were developed as prototypes. Compact Disc-Read Only Memory was tested as a low-cost method of