Tom Ayres, Chair
The NSO Users' Committee met in Tucson on 16 November 1999. Present were committee members T. Ayres (Chair, Colorado), T. Duvall (NASA/GSFC, stationed at Stanford), P. Goode (NJIT), D. Jennings (NASA/GSFC), K.D. Leka (Colorado Research Associates), and R. Shine (Lockheed-Martin). T. Brown (HAO) and E. Hildner (NOAA/SEC) were not able to attend. This was the first full UC meeting with new Director Steve Keil, following an informal gathering at the Chicago AAS in June, 1999.
The Observatory has been making dramatic progress on a number of fronts, but faces significant challenges in the near future.
The Committee applauded the strong scientific staff of NSO, who, despite increasing erosion of their research time by service projects, have won the past two Hale Prizes (Dunn, Harvey), and have been Co-I's on recently-selected proposals to build Solar-B instruments and to participate in a Center for Adaptive Optics, among other successes. At the same time, staff turnover has been high, particularly among the junior researchers at the Sacramento Peak site.
The Observatory's major initiative, Synoptic Optical Long-Term Investigations of the Sun (SOLIS), has completed design and management reviews and is currently in the construction phase, proceeding to deployment in the 2001 time frame. NSO's previous large project, Global Oscillation Network Group (GONG), continues to acquire a long-term helioseismology record, now during the rise to the maximum of the present sunspot cycle. A plan to upgrade the original GONG cameras to high-performance 1K x 1K CCDs has been implemented, and the system is expected to be operational in 2000.
At Sac Peak, a 20-actuator Adaptive Optics (AO) compensator has been demonstrated. The AO group is in the process of making it "user friendly" and is moving toward development of an 80-element system that would fully correct images from the 76-cm Dunn Solar Telescope --- a vital step to the even more complex compensators required by large-aperture solar telescopes of the future. The 3-station RISE/PSPT network is complete, and Sac Peak's engineering role in the upgrade of the Air Force ISOON solar monitoring network continues. The infrared program at Kitt Peak has secured an astronomical quality ALADDIN InSb chip, as part of a long-term effort to upgrade the IR instrumentation on the McMath-Pierce telescope. The Advanced Solar Telescope (AST) effort is rapidly evolving from the discussion stage to concrete plans to pave the way for a proposal to develop enabling technologies, test potential sites, and eventually build the new facility. In addition, the popular Digital Archive is expanding its holdings and improving its search engine and user interface. McMath-Pierce nighttime observations continue under a self-funding plan.
The Committee was impressed with the steady progress made by NSO in all of the areas mentioned above, in spite of its eroding budget. The Observatory has been able to fund certain of these efforts from its base --- the AO program, for example. However, these projects also compete for resources with other internal programs and under-funded external efforts (in particular RISE/PSPT for which construction money was provided, but support for operations was not). Some of these projects cannot continue without significant external funding. For example, full utilization of the new GONG cameras will require a major $1M upgrade of the data processing and analysis computers in Tucson. The AO program must have substantial funding to proceed to the 80-element compensator, with its more complex and demanding hardware requirements. The IR program needs a sophisticated dewar to house the ALADDIN array and an expensive controller to run it. The list goes on.
It is clear to the Committee that the present funding situation for NSO is not conducive to a healthy research organization. One must be able to support a mix of high-priority projects within the organization, not simply pick a top choice because that is all that a dwindling base budget will permit. The ultimate sufferers will be the users, who our committee represents, because NSO will not be able to push solar observing technology across a broad front of scientific disciplines. This would be a disaster for US solar physics, because unlike nighttime astronomy, the flagship ground-based observing facilities are at NSO sites. Thus, technological advances very much depend not only on NSO's willingness to develop them, but also its fiscal ability to do so.
It was against this backdrop that the Committee discussed the implications of a plan promoted by NSF and AURA to separate NSO from its parent organization, NOAO. There are several good reasons for an independent NSO, and many view it as essential if NSO is to obtain the credibility necessary to carry out a successful AST program. Such a separation carries potential dangers, however, to the extent that division of existing assets is not done fairly or if the administrative cost (ultimately borne by NSF) of running two independent organizations for daytime and nighttime astronomy exceeds that of the combined entity. The committee was unanimous in its concern over this issue and urges NSO to proceed cautiously in exploring it, and particularly to obtain a full accounting of the associated costs.
The committee discussed a number of other issues that might affect users. One was the degree of continuity in the changeover between SOLIS and KPVT synoptic data products. There clearly is a need for a substantial period of overlap between KVPT magnetograms and filtergrams and those provided by the SOLIS VSM and FDP instruments --- at least a month --- for cross-calibration purposes. This is somewhat of a tricky issue because the SOLIS site literally will be on top of --- and completely blocking --- the current KPVT. Thus, the "cross-calibration" cannot be carried out with SOLIS in its final observing location. Another issue involved the archiving of the huge flood of data that will be spewing out of SOLIS during its routine operations. Initially, the plan is to provide and archive a relatively limited set of observations, compatible with the synoptic material currently provided by NSO, but eventually to work toward retaining as much of the intermediate data products as future digital storage technology permits. Finally, the issue of the future of ground-based solar coronal physics was raised. Since the all-reflecting coronal imager was descoped from the original SOLIS plan to accommodate a funding shortfall, the future of ground-based coronal studies looks bleak; only the aging Evans facility will be available for such purposes, at a time when interest in exploiting newly discovered coronal diagnostics (such as magnetically sensitive Fe XIII 10747 in the near-IR) is on the rise. The perceived decline of ground-based coronal physics cannot be countered without substantial outside funding to develop a new facility; however, the incorporation of a coronagraphic capability in the AST might be a long-term solution.
In summary, the committee strongly endorses NSO's current plan to support its several projects that are critical to the user community and to develop --- to the extent feasible from its base budget --- the enabling technologies for a next-generation solar telescope, particularly high-order adaptive optics, site characterization systems (such as scintillometers), and infrared imaging and magnetography. The committee remains deeply concerned, nevertheless, over the recent attrition of the staff, the continuing depletion of staff research time, and the erosion of the base budget. Together, these factors restrain NSO from pressing forward key solar observing technologies --- and solar research --- across a broad front of disciplines. In the near future, a concerted effort will have to be made to convince the US solar physics community, the national funding agencies, and potential international partners to make a strong commitment, financial and otherwise, to support the aspirations of NSO to carry ground-based solar physics to the next level --- a state-of-the-art, large-aperture daytime facility.