In a joint ceremony Nov. 3, the Institute of Electrical and Electronic Engineers (IEEE) and the American Society of Mechanical Engineers (ASME) will commemorate the engineering and scientific contributions of Arecibo Observatory in Puerto Rico.

The 1,000-foot-diameter Arecibo radio/radar telescope, the world's largest, will be declared an IEEE Milestone in Electrical Engineering and an ASME Landmark in Mechanical Engineering. Arecibo Observatory will be the eighth recipient of these prestigious joint awards, most recently given to the Stanford Linear Accelerator. The award was requested by the Puerto Rico and Caribbean Section of the IEEE.

The Arecibo Observatory is part of the National Astronomy and Ionosphere Center (NAIC), a national research center operated by Cornell University under a cooperative agreement with the National Science Foundation.

The observatory was dedicated in 1963. Its unique design was based on the efforts of William Gordon, then a professor of engineering at Cornell, to build an instrument that would use radar to study the ionosphere, an upper layer of the Earth's atmosphere, and objects in the solar system. The telescope's radar transmitters and sensitive electronic systems for picking up and analyzing weak signals have produced a host of significant scientific results, from the first binary pulsar and confirmation of gravitational radiation, to detection of ice on the surface of Mercury.

"None of this would have been possible without the contribution of numerous innovations in radio frequency antenna, electronics and signal processing design," says Paul Goldsmith, director of NAIC and the J.A. Weeks Professor in the Physical Sciences at Cornell. "These honors reflect the creativity and dedication of the staff of the observatory and the NAIC. I join in saluting all the individuals, starting with Bill Gordon, who have contributed so much to technological and scientific innovation through their work with the wonderful instrument at Arecibo that is being honored through these awards."

The telescope's design also led to advances in electrical engineering, through antenna design, signal processing and electronic instrumentation. In mechanical engineering, it advanced antenna suspension and drive systems. The drive system, for example, positions all active parts of the antenna with millimeter precision, regardless of temperature changes and wind effects, enabling the telescope to maintain accurate focus and pointing.