Report of 59th meeting of SAC

Lyon, France, June 2-3, 2001

2 person rule
Queue/Service Observing
Proprietary Time
CFHT-WHT Time Sharing
 CFH Legacy Survey
PUEO upgrade
Next Generation CFHT

    The meeting was attended by SAC members Pierre Bastien, Jean-Luc Beuzit, David Bohlender (vice-chair), Laurent Drissen, Eric Emsellem, Eduardo Martin, Marguerite Pierre, Chris Pritchet, Genevieve Soucail (chair) and John Tonry.

    KAO (Korea) representative H.I. Kim and ASIAA (Taiwan) representative S.Y. Wang were present as observers.  G. Fahlman (Executive Director), C. Veillet (Senior Resident Astronomer), D. Salmon (Director of Engeneering) and other CFHT staff also attended and participated in the presentations and discussions.  J. Hesser (Chair of BoD) and S. Lilly (Director General, HIA) attended much of the first day of the meeting.

Agenda items

1. Technical activities report (Salmon)
     GRIF/KIR upgrade
     CFHTIR [performance report]
     Espadons [project status]

2. NOP status report (includes QSO, NEO, ELIXIR, DADS) (CFHT) and telescope scheduling (Veillet)

3. Trends in time application (CFGT, CTAC, UH)

4. Archive report (Bohlender)

5. Megaprime project update (Veillet)

6. OASIS and CFH12k disposition (Fahlman)

7. Megaprime survey: report of the working group, definition of the CFH Legacy Survey, organisation of the survey , proprietary time(s) and dataset/catalogue distribution, peer review of the survey, ... (Veillet)

8. WIRCam: funding, schedule, design (CFHT). Report of the Steering group (Beuzit).

9. (a) OHANA / (b) AOB upgrade

10. CFHT replacement studies: study of the reports, next actions (Fahlman)


CFHT technical reports, memos and reports were circulated before and at the meeting.  Most of the documents were made available on a secured Web site at CFHT.

1.  Technical activities report

SAC reviewed the detailed technical reports describing the different projects going on at CFHT.  SAC was impressed by the quantity and quality of the tasks carried out by the CFHT staff, and thus wishes to congratulate CFHT for its outstanding progress.  Some recommendations were made by SAC regarding specific issues:
Recommendation #1

    SAC strongly encourages the CFHT staff to carry on with the detailed evaluation of the seeing conditions observed at CFHT, their relationship to the site-dome-instrument environment, examine possible ways to improve these conditions, and to define a route of action.

Recommendation #2

    SAC was informed of the on-going activities for the FILAO instrument.  However, it was noted that 3 near-IR spectrographs are already available, or soon will be.  These include OSIS/IR, GRiF and FILAO.  Although each of them has its own capabilities, SAC is concerned about the level of scientific interest these 3 modes will hold for the communities. As an example, SAC notes that during semester 2001B OSIS/IR was available to the community but not a single proposal was submitted!  SAC therefore asks CFHT to perform an evaluation of the implications and cost of operating FILAO.  A clear evaluation of the science goals of FILAO via a scientific outline provided by the builders will be conducted by SAC.  SAC's evaluation will be sent to the TACs for additional comments.  This will help SAC obtain a clearer view on the operational conditions for these instruments, as well as their potential uses for the CFH communities.

Recommendation #3

    SAC encourages CFHT to continue to examine possible solutions of the ''2 persons rule'' concern at the summit during QSO.

2. NOP status report

    The SAC extends congratulation to all of the CFHT staff involved in the NOP project.  Remarkable progress has been seen in QSO, NEO, ELIXIR, and DADS since the last SAC meeting.  SAC recognises that this was only possible because of the very hard work and dedication of many CFHT staff members.
Recommendation #4
  • Concern with the current operation of the queue for semester 2001A was centered on the lack of QSO time devoted to UH programs up to the time of the SAC meeting.  SAC understands that this problem has arisen mainly because of a large number of programs from all agencies requesting observations with RA's near 12 hours.  To try to help CFHT produce a balanced observing queue, SAC recommends that once QSO observers have entered their Phase II information, CFHT staff quickly generates the observing queue. If there appears to be an imbalance in one or more member agency's QSO target or observing condition balance then the relevant TAC chairs should be informed about this promptly.  The TAC Chairs can then suggest adjustments in the scheduled QSO programs to ensure that the probability of observing programs being carried out to a high level of completion is high.
  • Currently there is very little direct feedback about the success (or lack of) QSO programs to the member TACs. SAC recommends that CFHT staff provide detailed QSO time usage accounting information to TAC chairs on a monthly basis, or at least after every QSO run.
  • SAC recognises that the preparation of the CFH12K queue requires a significant amount of effort and time on the part of CFHT staff. Presently the time intervals between the TAC meetings, the completion of Phase II input by queue observers, and the preparation of the queue are too short. A discussion on a possibile shift of the semester boundaries by one month with no changes in the current deadlines for proposal submission occured. A final decision should be proposed for the next SAC meeting after a better evaluation of the Phase II preparation problems. 
  • SAC continues to urge CFHT, on a semester-by-semester basis, to educate the CFHT observing community about what is needed for successful QSO operation.  In particular, observers should be reminded that the better the observing conditions they request, the lower the probability of successful completion of their program unless they happen to be among the top few scheduled QSO programs for his/her agency.  Time applications for Snapshot programs that can provide useful science during poor observing conditions must also be encouraged. To help TAC Chairs make good decisions when adjusting observing constraints for QSO programs (for the purpose discussed above) SAC recommends that a new field be added to the Phase I tool, POOPSY. This new field will allow applicants to indicate the poorest possible seeing requirements that will still enable his or her program to achieve the proposal's stated scientific goals.

The success of CFHT staff in discovering low-level light scattering from the back of the mirror covers was viewed as a solid demonstration of the robustness of the ELIXIR data reduction pipeline.  SAC and the member communities will look forward to the official release of the first data products from this package.  When this, and subsequent data releases take place the SAC also strongly urges CFHT to make all of these data products and the relevant ELIXIR database tables available
to the CADC so that calibrated data may be made readily available to all CFHT archive users.

Again, SAC reiterates that we are extremely pleased with the great progress made in the entire NOP project.  We will look forward to another status report at the next SAC meeting in November 2001.

3. Trends in time application

    SAC reviewed the proposal pressure and time allocations for the 2001B 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.  SAC also noted that the pressure on bright nights exceeded that on dark nights.

No proposals were submitted for the new OSIS-IR observing mode.

4. Archive report

SAC received a detailed report from CADC and is pleased with the on-going activities at CADC.  Prior to the Lyon meeeting, SAC e-mail discussions about the proprietary period for QSO data has led to the following recommendation:
Recommendation #5
  • SAC asks the national TACs to inform CADC and CFHT of any approved extension of the proprietary period as soon as possible after their respective meetings.
  • SAC recommends that the proprietary period for observations conducted in QSO mode be one year from the end of the semester for all queue programs scheduled during that semester.  Classically scheduled programs will continue to have proprietary periods of one  year from date of acquisition.

SAC notes that MegaPrime and the CFHLS present a major challenge to the three major partners involved in data handling and processing: CFHT, TERAPIX, and CADC.  There is much work that needs to be done in the next 12 months including tasks ranging from definitions of data exchange mechanisms to technical details of database and processing systems.  This is an urgent priority and the CFHT, TERAPIX, and CADC must begin active discussions and collaborative development
immediately if a data distribution and processing system is to be ready in time for the first MegaPrime science runs, currently anticipated in 2002 August.

5. MegaPrime project update

    SAC expresses its concern about the delay in the construction of the Megaprime autoguider unit by HIA and recognises that this situation arose because of a lack of manpower available for the project.  Compared to the schedule presented at the last SAC meeting (December 2000), the current delay amounts to about 4 months.  Reducing the initially scheduled period of acceptance tests would then result in Megaprime being ready by April 2002.  SAC views this as a critical deadline to meet if Megaprime is to be available for scientific use for semester 2002B, as is currently planned.  SAC stresses the urgency to keep the schedule in order for the project to remain scientificly competitive.  Any additional delays should be communicated to SAC immediately.

6. OASIS and CFH12K


SAC discussed the status of the OASIS move to the WHT, tentatively planned for the end of the 2002A semester.  In this context, and given SAC's recommendation to shift semester boundaries (see section 2 above), SAC makes the following recommendation on OASIS:
Recommendation #6
  • SAC recommends OASIS availability at CFHT be advertised for the full 2002A semester (1 Feb - 31 August).  The SAC agrees that the Lyon group may remove OASIS from CFHT after the last OASIS run scheduled in semester 2002A.
  • SAC requests that the Lyon group report on the status of the OASIS move to WHT, and particularly on possible delays, after having obtained a detailed progress report regarding the NAOMI/WHT adaptive optics system from the WHT. This report should be received by SAC in 2001 September.  SAC asks to be informed of any change (i.e. delay) in the original disposition schedule, as written in item 1 above.  Any proposed extension of the availability of OASIS at CFHT for the 2002B semester should be processed via a formal request to SAC, which will review it in the light of the support 

WHT / CFHT exchange time

SAC received the proposal which suggested a means for providing the CFHT community with access to OASIS after it is moved to the WHT in exchange for time on Megacam.  However SAC clearly states that the approval of such a time-sharing proposal is strictly conditional on the interest from the C, F and H communities to have access to OASIS at the WHT.  This should be evaluated before SAC can formally support such a proposal.  SAC thus makes the following recommendation:
Recommendation #7
  • SAC supports the present negotiation between CFHT and WHT to have a time-sharing program, specifically between the OASIS (when moved to WHT) and Megacam/CFHT instruments.
  • SAC will review the TACs evaluation of the support from the different communities for continued access to OASIS at the CFHT and WHT before endorsing any formal proposal. 


    SAC was informed by the Executive Director of a possible opportunity to move the CFH12k camera to another facility. The estimated investment in the camera is estimated to exceed $1M. SAC encourages CFHT to evaluate the present market value of the CFH12k camera, recognising that the CCD chips are still quite efficient ones on the present market, and that the filters and the mechanics are also valuable.  Moreover, SAC requests that the departure of the CFH12k camera from CFHT should wait until at least one year after the start of Megacam operations.

7. Megaprime survey

    SAC thanks the MSWG for the preparation of their draft report for a Canada France Hawaii Legacy Survey. Based on discussions at the French and Canadian national astronomy meetings and at the 2001 CFHT Users' Meeting there is clearly strong interest for such a MegaPrime survey from the French and Canadian communities, and the SAC agrees that such a survey should be carried out at some level.

The University of Hawaii has indicated that they are very unlikely to participate in the CFHLS at the 110 night/year level currently proposed and would prefer an allocation of survey nights much closer to the 42 night/year level currently guaranteed to survey programs. The UH SAC representatives reiterated the fact that the UH's current demand for CFHT time remains at a level equal to UH demand for the Keck Telescopes. This is primarily because of their interest in wide-field optical imaging needed for support of their 8-m telescope programs. As a result UH is very hesitant to give up a large fraction of the dark and gray nights available for UH PI programs with the CFH12K camera. This is despite of the fact that participation in a CFHLS would give them immediate access to many more nights of MegaPrime data than they currently have proprietary access to.

Because of these issues, at this time SAC is not able to recommend a precise number of nights that should be assigned to the CFHLS. Instead, SAC now requests that the MSWG prepare a detailed CFHLS Observing Proposal which will eventually be submitted to the SAC, TACs, and external referees for review. After the TACs and external recommendations are received and reviewed, SAC will then be able to provide a final recommendation for the number of nights to assign to the Canada France (Hawaii) Legacy Survey.
Recommendation #8

  SAC recommends that the CFHLS Observing Proposal should address the following points:

  • SAC agrees that the idea of deep and shallow components in the survey is very good and these components should be maintained and should continue to form the heart of the observing proposal.
  • More detailed discussions of the science cases for the remainder of the community need to be included in the proposal and the MSWG is strongly encouraged to draw a wider participation from interested members of the member Communities. The SAC will also contact representative members of the community and urge their participation in the preparation of the CFHLS proposal. Clearly if a large number of astronomers with a broad range of scientific interests can be convinced to add their name to the final submitted proposal the case for the CFHLS is made much stronger.
  • The observing proposal must provide a detailed observing strategy including:
    • Target fields which include a wide and even distribution of RA's (to facilitate operation of the observing queue)
    • Science cases which make use of a wide range of observing conditions (again, to facilitate operation of the queue and toensure that a fair distribution of observing conditions remains at the disposal of traditional PI programs)
    • Accurate accounting of the percentage of time with given observing conditions required by the component survey programs and the survey in general
    • A clear, quantitative indication of the minimum requirements needed (number of nights and observing conditions) and a quantitative justification for why the "ideal" requirements requested might exceed these minimum requirements
    • Details of a "ramp-up" strategy for the first semester of the survey if it is deemed desirable or necessary. Support for such a ramp-up is generally, but not unanimously, encouraged by SAC to enable the survey team to refine observing techniques to assure uniformity of data quality and to ensure that all components of the Survey (such as the SNe program) are feasible.
    • A clear outline of proposed management of the project as well as observing milestones that will be used for future evaluation by TAC and external referees.
Deadlines for preparation of the CFHLS Observing Proposal are outlined below and are, admittedly, demanding. However, these deadlines must be met in order for SAC to prepare a recommendation to the CFHT Board of Directors by no later than the 2001 November 16/17 SAC meeting. Obviously if the MSWG can submit documents at an earlier date then the SAC will make every attempt to expedite the review process. If the MSWG believes that a more aggressive time-line is possible then this should be communicated to SAC immediately. Note also that the SAC will provide the MSWG with comments on the initial draft of the proposal. The final version is then to be submitted for final review by the TAC and external referees. The TACs participation on review of the first draft of the
proposal will consist of suggestions for external referees. In all cases, the final recommendations of TACs and SAC will be based on the scientific merits of the proposed CFHLS science balanced against the value of traditional PI proposals.


  • 1 September 2001: draft CFHLS Observing Proposal delivered to SAC (for distribution to SAC members and TACs)
  • 15 September 2001: SAC returns comments on draft proposal to MSWG
  • 1 October 2001: Final CFHLS Observing Proposal submitted to TACs for TACs and external review
  •  November 2001: Deadline for receipt of external referee reviews by TAC
  • 12 November 2001: Deadline for receipt of TACs recommendation by SAC
  • 16/17 November 2001: final SAC review and recommendation of the number of nights to assign to the CFHLS for semester 2002B. (Note: if the current schedule for MegaPrime availability to the community slips much later than the current date of 2002 August then the start of the survey may be deferred until semester 2003A.)
  • 12-15 December 2001: CFHT BoD meeting
  • ~15 February 2002: Based on BoD decision on CFHLS time request, CFHT circulates Call for Proposals for semester 2002B, indicating approximate number of nights available for non-CFHLS programs.


    SAC received several documents regarding the status of the WIRCAM project, including the final reports of the two study contracts submitted by R. Doyon et al. (U. de Montreal) and K. Hodapp (IFA, UH) for the conceptual design of the instrument. In particular, Doyon et al. propose a modular design, allowing a continuous field (no gaps between detectors) with a possible increase of the total field of view by 50%, moving from 2x2 to 2x3 detectors. Several options were
presented by Hodapp related to new array developments at Rockwell: use of the new MBE material for the Hawaii-2 FPA that will result in higher QE and reduced residual images, buttable arrays still under development for the NGST project.

SAC wants to congratulate CFHT for reaching the level of progress presented at the Users Meeting and during the SAC meeting. Several options are still open and subject to debate, and should be addressed very soon by the WIRCAM Steering Group.  SAC endorses the project management plan presented by CFHT.  SAC is still concerned with the time-scale of the project, to be compared with other on-going projects of wide field IR imagers.  It appears that the two most competitive projects are NIRMOS on the VLT (should start operations by the end of 2002 but NIRMOS will be sensitive only in J and H) and WFCAM on UKIRT
(WIRCAM is foreseen to be ready in 2003, with a possible shift to 2004).

SAC also recognises that once the final design is fixed, the manufacturing of WIRCAM can be rapid, provided that a good complementarity is maintained between the groups involved in the project.
Recommendation #9

  SAC urges the Steering group now in place to comment on the optical and chip options, but also reminds the group that the most important issue on WIRCAM is the tight schedule.  SAC therefore recommends that the project be started as soon as possible in order to have the camera on the telescope no later than semester 2004A.  As a first step, CFHT should try to position itself in the IR detector manufacturer's "queue" as soon as possible.

9.   OHANA and PUEO upgrade

    SAC reaffirms its support of the OHANA project and therefore encourages CFHT to continue to lead the project and discussions with other telescopes on Mauna Kea in this matter.  SAC is, however, concerned about the lack of funding for this project.

    SAC is very supportive of the efforts led by O. Lai and F. Menard to study the technical and logistical considerations for upgrading PUEO, which has been, and still remains, one of the best AO systems available on the planet.  There is still a strong demand from users for PUEO, which will be an essential component of the Ohana project.  An upgrade of PUEO would therefore be a strong asset for CFHT and its users, and SAC encourages CFHT to pursue its efforts in this area.
Recommendation #10

    SAC recommends that the PUEO group upgrades its report by the next SAC meeting, with an emphasis on the following considerations:

  • fully develop the science cases, requesting input from members of the three communities; the evaluation of the sky coverage for different programs must be addressed. 
  • provide a detailed cost analysis and scientific impact of the different options;
  • provide an analysis of the manpower required from CFHT (in particular make sure that it does not delay the implementation of WIRCAM).
  • investigate possible sources of funding and manpower outside of CFHT (such as the CFI-International in Canada).

10.    CFHT replacement studies

    The final concept studies for a Next Generation CFHT were sent to SAC before the meeting, and a general discussion of the 3 concepts was presented by Greg Fahlman at the User's Meeting.  SAC is very impressed with these design studies, particularly since they offer so many innovations over the other designs pursued by other groups in the world:  GSMT, CELT, OWL...  SAC wants to congratulate the three groups for their excellent work and innovative ideas.

    There was lively and extensive discussions during the SAC meeting about what an NGCFHT should be and how to converge on a design.  Several points emerged:

Recommendation #11

    SAC suggests that the board find extra funds to permit CFHT to carry on a series of NGCFHT workshops which can be used to bring in telescope engineering experts and the participants from the concept studies to hammer out a workable design that all can agree on.  These workshops can also bring in scientists from the communities and elsewhere to refine the science cases which are already detailed in the Burgarella and Carlberg design studies.  Finally, workshops can begin to make the idea of an NGCFHT credible to the world, an essential step for an eventual effort to find funding for an NGCFHT.

11.   Future meetings

        The next SAC meeting is scheduled for November 16-17, 2001 in Waimea.