Mount Laguna Observatory Astronomers Benefit from HPWREN

Situated at an elevation of 6100 feet, San Diego State University's Mount Laguna Observatory (MLO) is 35 air miles east of the SDSU campus (on a direct line of sight) and 45 miles from metropolitan San Diego. Modern astronomical telescopes are equipped with electronic imaging detectors known as CCDs, which consist typically of arrays of two thousand by two thousand pixels. An astronomer at the observatory can generate a few hundred images on a long winter night. In order to transfer the data from Mount Laguna to on-campus facilities, or to other collaborators world wide, digital audio tapes (DATs) are currently used. However, high-speed Internet access provided by UC San Diego's HPWREN project will soon open up a new opportunities for MLO astronomers.

This versatile 40-inch telescope is used for astronomical research at MLO. It is equipped with various auxiliary instruments including two CCD cameras, a Cassegrain spectrograph, a Near-IR camera, an automated photometer, a coudé bench spectrograph, and a grism spectrograph.

Moreover, remote observing via the Internet has the potential to increase efficiency, broaden the user base, and to open significant research and educational opportunities, as astronomy becomes a global enterprise. "By providing high-speed Internet access with this wireless network, we'll not only enable much more efficient operation of our active astronomy program, we'll also provide a real-world testbed for this prototype network," MLO Director Paul Etzel says.

One such opportunity includes the ability for astronomers to quickly transfer images from the observatory to their image-processing laboratory on campus, to other collaborators, or to classrooms the next day. For example, comparisons of new images can be made to archival images of the same sky fields to look for the appearance of novae and supernovae in other galaxies. Rapid response is also needed to identify optical counterparts to gamma-ray bursts that are found by orbiting spacecraft. In the future, queue scheduled robotic observing programs could expand classroom participation, or allow real-time observing by the public from the Reuben H. Fleet Science Center (located in San Diego's Balboa Park).

"Although we're only 35 line-of-sight miles from our home campus at SDSU, the observatory is still too remote for us to be served by anything but a single, dedicated phone-line that can only transmit data at 30 kilobits per second," Etzel says. "This is somewhat problematic, as modern CCD-equipped telescopes can generate hundreds of images per night, each one eight megabytes in size."

The wireless connectivity at MLO, which serves as one of four HPWREN backbone nodes is progressing relatively quickly, and is expected to be deployed by the end of this year. MLO and the three additional backbone nodes currently use Western Multiplex Tsunami 5.8 GHz radios and will incorporate IP routers. Radios with point-to-point or point-to-multipoint capabilities will be used to connect network access links (user sites).

Glen Offield and Bud Hale install a four-foot antenna for the Mount Laguna Observatory high-speed connection. This antenna points toward a relay located atop Stephenson Peak, which points to a relay atop Cuyamaca Mountains, which points to a relay atop Mount Woodson, which points to an antenna atop the San Diego Supercomputer Center - where the HPWREN network is connected to the Internet, including its high performance components such as Internet2.

The Mount Laguna Observatory is operated jointly by San Diego State University Astronomy Department and the University of Illinois at Urbana-Champaign. The observatory was dedicated in 1968, and was built with funding from the National Science Foundation, with matching funds provided to SDSU by the State of California. The facilities include three research-grade telescopes of 16-, 24- and 40-inch apertures, and a 21-inch telescope for public viewing in conjunction with the Summer Visitor's program operated jointly with the United States Forest Service. The observatory also has a four-bedroom dormitory, a full-service shop building built with State funds, and a four building Visitor's Center built almost entirely with private funds.

SDSU is currently raising funds to construct a 100-inch class telescope. Potential partners for this proposed telescope could be located anywhere in the world as they could now use it over the Internet. Astronomers on the east coast of the United States, Europe, or Asia could sit at workstations at their home institutions and have the "feel" of being in the control room right next to the telescope on Mount Laguna. The wireless network access could efficiently transfer observational data, command and control language, and even slow scan video for target acquisition. By forming a global network of such telescopes, participating astronomers could observe selected objects for days as night falls over each observatory in succession, and hence open up novel research possibilities such as searches for extra-solar planets and gravitational lensing events, and quasar monitoring.

Additional photographs regarding the Mount Laguna Observatory are available at /Photos/sites.html#Laguna.

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