Report of 58th meeting of SAC

Waimea, Hawaii, Nov 29-30, 2000



MegaCam Survey Working Group
WIRCAM Project
CFHT Replacement Studies
OASIS withdrawal
MegaPrime Project
Instrument Priorities
Waimea Observing
 Queue/Service Observing

        The meeting was attended by SAC members P. Bastien, J-L Beuzit, D. Bohlender, J-G Cuby, L. Drissen, J. Hutchings (chair), M. Pierre, G. Soucail (vice-chair), J. Tonry, and R. Wainscoat. KAO representatives H. Kim and W. Han were welcomed as participants. G. Fahlman, C. Veillet, D. Salmon and other CFHT staff participated in presentations and discussions. CFHT board chair J. Hesser also attended.

    The agenda are listed below, and the report covers these items in the same order.

Agenda items

1. Megaprime surveys and working group report, future plans (Veillet)
      Also Terapix progress (Mellier report)

2. WIRCAM funding, partners, schedule, design (CFHT)

3. CFHT replacement ideas, schedule, funding and partners, future meetings
      (preview of study reports for CFHT21 meeting)

4. Trends in time applications (CFGT, CTAC, UH reports)
      (Numbers of proposals, oversubscription, instrument demand, KAO time)

5. Overall long-term instrument plan in view of 1 - 4 above

6. Queue scheduling plans and progress  (CFHT)
      (Phase 2 tools, Elixir, data handling and delivery, Waimea observing)

7. CFHT users meeting - date and place, topics, speakers, organisers

8. Megaprime project update (Veillet)

9. Update on other instruments and initiatives (CFHT, Rouen, Catala, Bacon)
      (GRIF, OHANA, Espadons, KIR upgrade, CFHTIR for OSIS, OASIS future)

10. Other current issues (CFHT)
      (Dome painting, dome ventilation, telescope oscillations, CCDs)

11. CFHT data archive issues (CFHT, HIA)


    CFHT technical reports, memoes on data archives and OHANA, CADC reports, SAC email correspondence, and reports from Terapix, Espadons, and the IRWG were circulated before or at the meeting.

1.  Megaprime surveys and Terapix Report

SAC was pleased to receive a detailed report from the Terapix project, which had been requested, and which dealt with many questions of
data handling and processing.

SAC approved the following changes to the Surveys Working group: S. Lilly and H. Richer replaced (due to their assuming major new duties) by R. Carlberg (Univ of Toronto)and D. Schade (CADC). SAC also recommended that Y. Mellier be invited into the group to coordinate Terapix activites, preferably by replacing one of the French members of the group.

SAC was given a verbal progress report of the Megacam WG, and of their proposal for a large CFH Legacy Program amouting for 500 to 1000 nights, to be spread over ~ 5 yrs, covering, and extending beyond the originally identified scientific programs. In view of these developments, and of its previous recommendations, SAC has the following recommendation, noting particularly the importance of the dates and deadlines indicated:
Recommendation #1

We urge the Megacam Survey Working Group to meet, as planned, in January 2001, and provide during February 2001 a detailed plan, including:

- the scientific programs
- the areas of the sky to be covered
- the justification for the total number of nights, noting the individual  survey programs
- the priorities among scientific goals, and their completion schedule
- the observing schedule, with attention to 
  i) optimisation of science goals, and their defined completion time, 
  ii) time constraints for programs like SN or TNO searches and follow-up
- the rationale for the merging of the individual survey programs into a wider Legacy program

 SAC considers this process to be urgent and essential to establish the survey program, particularly if the amount of survey time recommended is to exceed the nominal 6 weeks per year originally suggested. After reviewing this detailed plan, SAC will evaluate the potential for a  Legacy Program, and recommends the plan to be distributed to the communities for feedback. SAC endorses the idea of holding regional meetings early in 2001 for this purpose. It is essential that the Megacam survey plan be very fully developed by the end of the users meeting 2001, and for the  agencies to approve the use of the telecope time.

In addition, and in view of the likely development of the WIRCAM project, SAC requests that a preliminary assessment be made of the possible extension of the surveys with WIRCAM.

SAC continues to urge the WG to work with CADC, Terapix, UH and CFHT,  to evaluate and make recommendations for:

- the pipeline requirements, in view of the current TERAPIX status
- the requirements for ancillary data (e.g. calibrations, weather information)  to enable full use of the data by the participating scientific communities
- policies for data proprietary time within the survey communities
- data distribution and archiving policies for raw and reduced data, inside and outside the participating communities. Of particular concern is the implementation of some mechanism allowing rapid access to the survey data for time-critical programs. The role of CDS, as given in the Terapix report, needs to be clarified
- the peer review evaluation of the surveys (see SAC 55th meeting report)


 The SAC received a progress report on negotiations to secure funding for WIRCAM. The SAC was very encouraged by the progress, and stresses that final agreement must be reached very soon to allow thw WIRCAM project to proceed at a rapid pace during 2001. SAC congratulates and thanks the CFHT director for pursuing and completing these important partnership arrangements.
The SAC also received the science case report of the Infrared Working Group.
Recommendation #2

The SAC reaffirms the very high scientific merit of wide-field imaging in the infrared, but stresses that there is a narrow time window during which WIRCAM must be developed for it to have maximum scientific impact. In particular, several comparable cameras are expected to come into operation during 2004. The SAC therefore recommends that an agressive timetable is adopted for the design and construction of WIRCAM, including a call for detailed competitive designs early in 2001, and use on the telescope in the first semester of 2004. The SAC noted that two-edge abuttable 2K x 2K chips are in development, and requests that these be considered carefully because they could allow more economical designs, and would allow the four imaging arrays to be close-packed (thereby making survey work much more efficient).

The SAC found the report of the Infrared Working Group valuable, and will seek a group like this immediately, to operate as a steering group during the design and construction of WIRCAM. The mandate of this group will need to be drafted. The IRWG (or the new steering group) should also draw up a short document outlining the performance and science drivers of WIRCAM for posting on the CFHT wesbite.

The SAC was very enthusiastic about the progress being made in developing possible replacement telescopes for the CFHT. It was noted that in an optimistic schedule, construction of a replacement telescope could commence as early as 2007. The SAC felt that the possibility of an early replacement telescope for CFHT did not in any way diminish the strong scientific need for WIRCAM. Instead, it underscores the importance of proceeding very aggressively with the design, fabrication, and commissioning of WIRCAM.

3. CFHT Replacement Studies

    The SAC previewed the concept studies for CFHT replacement that were to be presented at the CFHT21 celebration meeting. There was unanimous enthusiasm for the goal of a telescope in the 15m and larger aperture category, and was gratified that the studies selected earlier in the year have made such impressive progress.
Recommendation #3

   SAC continues to note that CFHT will be less and less competitive as the decade progresses with the development of a number of 8m class telescopes about to come on line. The planned use of the CFHT primarily for wide field imaging using Megacam and WIRcam will help prolong its ability to do unique science.  However, CFHT will soon need exciting 
future plans if it is to retain the best staff and remain a forefront telescope facility.

   With recommendation by SAC, CFHT has issued contracts to the following groups to pursue studies of a possible next generation CFHT. These studies are to be presented at the CFHT celebratory meeting at the end of November 2000, with final, written reports due in May 2001.

  o  Burgarella et al (Observatiore Marseille) `A Versatile Wide Angle Survey Telescope for the Next Generation CFHT'
  o  Carlberg et al (Canadian consortium) `The CFH Mammoth Telescope' 
  o  Kuhn et al (University of Hawaii) `CFH High Dynamic Range Telescope'

   These studies are an essential first step, but are not yet nearly thorough enough to be able to be certain about engineering feasibility or cost, and therefore cannot yet be used to seek funding for such a telescope.  They do, however, give a clear signal that CFHT replacement is an extremely important issue.  Efforts must be continued as rapidly as possible, probably with an infusion of new money from the board, since the funds allocated in 1995 have been exhausted by these studies.  It is desirable to include CFHT staff in studies,
and SAC feels strongly that the continued initiative for a next generation CFHT must come from within the organization. SAC supports every effort to maintain the momentum and activity of these studies.

   SAC would like to receive the study reports as soon as they are submitted, and the reports should definitely be made public before the CFHT users meeting in late May 2001.  This users meeting will include a forum for a detailed discussion of the merits of the different designs (or other ideas), ideally culminating in an agreement on a desired design and a resolution to move forward with the engineering studies necessary to pursue funding for the project.

   Recognizing that the cost of such a telescope will be of order $150M, SAC encourages CFHT to seek possible partnerships outside of Canada, France, and Hawaii, for example Korea. 

   SAC applauds the work done for these proposals, and is impressed that the telescope designs have capabilities which go well beyond any existing or planned telescope, and therefore will remain competitive well into the future.  It is essential that the interest and momentum created by these studies not be lost, and CFHT must act decisively to continue progress on the next generation telescope.

4. Trends in observing applications

     SAC reviewed the proposal pressure and time allocations for the 2001A semester, as reported by the national TACs and the scheduling plans by the TAC.

     CFHT12K is currently the most widely requested and used instrument on the telescope. SAC notes that there is high demand for the following instruments, in roughly decreasing order:  AOB, OASIS, MOS, Gecko/CAFE, and the newly commissioned CFHTIR.
Recommendation #4

     After learning about the planned withdrawal of OASIS, SAC is concerned over OASIS in particular, as it is a widely-requested instrument. SAC is concerned about similarly-provided instruments in general, and recommends that notice of at least 2 semesters be given before the instrument be taken away. For OASIS, this would be not before the end of semester 2002A. This would allow interested users to plan their research proposals over the whole sky.

5. MegaPrime project

  SAC reviewed the progress of the project, and is pleased at the excellent CCD quality and the fact that all 40 will be placed in the camera. There was discussion of the procedures, should any changes be required in the CCD mosaic, as we wish to reduce down time and risk involved in transporting the camera to CEA. SAC was later assured that there are plans to allow such work to be done in a clean room at CFHT. Thus, the second paragraph in the recommendation below serves to simply record the concern, which we believe to be accomodated in the present plans.
Recommendation #5

   SAC is pleased at the excellent progress in the Megaprime project, and the news that it remains on schedule for March 2002. The extra effort that has been made by CFHT staff to achieve this is appreciated.

   SAC is pleased that plans have been made to ensure that any CCD replacement or reconfiguration be done at CFHT. The risk and time taken if these had to be done by shipping to CEA, would be very undesirable.

6. Instruments and priorities

     SAC reviewed and discussed the instrument projects outlined in the CFHT technical reports and given in the last SAC report. The following recommendation updates the priorities of the SAC.
Recommendation #6

      The Megaprime project will dominate most of the technical activities at CFHT for the year 2001, until the first light foreseen for March 2002, and full science operation in semester 2002B.

     CFHTIR-OSIS will have tests on the telescope in May 2001 and the results should be reported to SAC, particularly if there are unexpected problems. In any case it remains behind Megaprime in priority.

     Full use of GRIF will await the KIR upgrade, but is expected to be available for semester 2002A.

    Other instrument projects were discussed but at this stage do not appear to impact CFHT activities significantly. Among them,

1.  SAC reaffirms its support of Espadons, and wishes to see it available by 2003. SAC supports the requested extra funding from CFHT, provided Espadons also receives its funding from other sources.

2.  SAC agrees that the OHANA project be pursued. It is noted that OHANA implies the continued maintainance of AOB, and possibly its upgrade.

3.  As requested by HIA, SAC agrees to the return of the Herzberg spectrograph to Victoria.

7. Waimea observing

      The Waimea observing room was shown and demonstrated to the SAC. SAC is pleased that this facility is now working and also that Waimea accomodation for visiting observers will soon be available. This facility, and the planned level (and increase) of service observing raise the following issue for staffing of the observing.
Recommendation #7

  The start of service observing and its expected increase as Megaprime is commissioned, will introduce signficant problems with CFHT staff in following the two-person summit rule, since the service observer can operate fully and more efficiently from Waimea. SAC urges that alternatives be investigated to ensure safety at the summit. Possibilities include personal audio or video links. As this problem is not confined to CFHT, there may also be joint ways to seek solutions among the Mauna Kea facility communities.

8. Queue Scheduled Service Observing

   SAC was given detailed demonstrations and presentations on the queue scheduling tools and phase 2 observer input interface, and the Elixir developents.

   The SAC is very impressed with the tremendous progress that has been made in QSO development since the 2000 May meeting, and congratulates the CFHT QSO team for their efforts.
Recommendation #8

  1. SAC urges CFHT to continue to educate CFH12K applicants, as well as the national TACs about the requirements for successful operation of QSO. 

  2. In particular, potential users should be reminded that QSO blurs the traditional Right Ascension boundaries of the current observing semesters.  For example, targets which may be optimally positioned for classical observing in October might be readily observed in queue-mode in July. 

  3. TACs must continue to make efforts to ensure that agency queues contain proposals requiring a complete range of observing conditions and target coordinates. 

  4. The CFHT communities should also be encouraged to submit more snapshot proposals which can produce important scientific results in less-than-optimal observing conditions.

  5. At the current time, SAC recommends that proposed changes in targets from those indicated in a PI's original observing proposal should be forwarded to the CFHT Director who will evaluate the possible impact on the execution of the CFH12K queue, as well as the proposed science.

  6. There continue to be concerns among SAC members about the calibration plan for QSO.  Care should be taken to ensure that observing time is not wasted with the acquisition of photometric standard field observations during obvious non-photometric conditions.  Brief mention was made of a CFHT investigation of the implementation of a small telescope to monitor sky conditions, and SAC urges CFHT to investigate the possibility of using this telescope to obtain photometric data in support of both QSO and classical observing with the CFH12K camera, and later with MegaPrime.

  7. SAC reiterates the importance of ensuring that the design and operation of QSO should result, when observing conditions permit, in the execution and completion of programs given the highest scientific ranks by the member TACs.

  8. SAC requests that a progress report on QSO and Elixir operation be presented to the SAC at the 2001 May meeting, or earlier as problems arise. 

9.   Other matters

      In view of the shortness of the SAC meeting, there was not time to review other matters in depth, or to make other detailed recommendations.

      Issues and memoes concerning the CFHT archive were reviewed and noted, including the general memo on archiving from the CFHT director to SAC and the Board, and the report and comments from CADC. It is felt that there are no major problems, but note that detailed communications should continue between CADC and CFHT, as previously recommended by SAC.

      Other items described in the CFHT technical reports were noted but not discussed. These include dome painting, the CFHT12K shutter, CCD news, the commissioning of CFHTIR, and the primary mirror support. SAC appreciates the work by CFHT staff in all these matters.

10.   Future meetings

        SAC members Hutchings, Cuby, and Wainscoat retire at the end of 2000. New members will be announced in the new year. G. Soucail will be SAC chair starting in 2001.

        SAC anticipates supporting regional meetings of the MSWG after receiving its survey plan in February.

        SAC has scheduled the next users meeting for May 31-June 1 in Lyon. The agenda will include discussions on CFHT replacement studies and plans, the Megaprime survey science, and QSO operation. The SAC should meet at the time of the users meeting. Because of the closeness to the dates of the CASCA meeting on May 27-29, and the French holiday weekend, the schedule for the SAC meeting needs to be resolved.