Report of 61th meeting of SAC
Québec, Canada, May 5-6, 2002
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, Geneviève Soucail (chair) and Brent Tully.
Taiwanese representative S.Y. Wang was present as observer. Greg Fahlman,
Christian Veillet, Derrick Salmon and Jean-Charles Cuillandre participated
in the discussions as CFHT representatives.
1. Time allocation and observing issues (Martin, Veillet)
Trends in time application (CFGT, CTAC, UH)
2. Technical activities report (Salmon)
and Project Reports
Gecko: status of the UV train
Fly Eyes (Cuillandre)
Report of the Steering group (Beuzit)
Need for a "WIRCam legacy survey"?
Links with UKIDSS, the UKIRT Infrared Deep Sky Survey
5. MegaPrime project
First light, instrument characterization and photometric calibration requirements
Start of the SG mandate
Start of the survey. Planning for the 2002 year
Registration procedures and policies
Data proprietary time and definition of data releases
7. Other issues
SAC strongly expresses the statement that the foremost priority of QSO remains the high-level completion of A-grade proposals.
As it is the case for visitor mode, CFHT should solicit user reports on the operation of the QSO/NOP/DADS system.
This might, for example, provide
information about the impact of <100% data validation on PI programs.
Results should be presented to SAC in 2002 November.
SAC recommends that CFHT should continue to pressure the Mauna Kea Weather Center to improve the timeliness of this service. If there continues to be no action on the part of the Mauna Kea Weather Center, SAC requests an estimate of the resources required to implement CFHT's own all-sky IR camera and seeing monitoring facilities.
SAC's final recommendation is that if QSO managers see A-ranked programs that will not be completed then CFHT can contact the relevant TAC(s) chair to see if these should be carried over to the first QSO block of the subsequent semester. It is anticipated that only 1 or 2 programs per agency will be extended in this manner.
In order to reduce the effect of
semester boundaries, the concept of a 1-year schedule was also suggested
but needs more attention before any action can be taken. SAC encourages
CFHT to explore the impact of such a schedule change on QSO operations
and to propose practical solutions. SAC will discuss these at the
next SAC meeting and will ask the agency TAC's to discuss this possibility
with their communities.
SAC received detailed comments from D. Salmon about on-going technical activities at CFHT: dome maintenance, F/8 secondary mirror aluminization, on-going investigations on the declination oscillations of the telescope. Recent detectors developments are strongly supported by SAC, especially the MIT/LL CCDs. There is concern about the failure of one quadrant of KIR. SAC encourages the CFHT technical staff to find a rapid solution which will not interfere with the current schedule of observations: possibilities include repair of the device by Rockwell or replacement with an engineering-grade device of sufficient quality.
A review of the different projects
and developments is presented below.
SAC recommends that no change in project priorities be made for the upcoming months.
SAC acknowledges the information on the development plan of the project. As the detectors have been ordered recently after a few months delay, a shift of approximately 3 months in the overall development plan is now foreseen since the detectors are on the critical path of the project. With a detector delivery by the end of 2003, it is now expected that WIRCAM will be on the sky during the summer 2004.FlyEyes
Pascal Puget has volunteered as WIRCAM Project Manager. SAC applauds the efforts of Derrick Salmon as interim Project Manager in moving this important project forward quickly.
A detailed presentation of the FlyEyes experiment was presented by J.C. Cuillandre. SAC wants to congratulate CFHT staff on their initiative in pursuing this upgrade path for PUEO. The experiment should continue, but not at expense of other high priority CFHT projects. Considering the fact that FlyEyes cannot be on the sky before the end of 2002, SAC requests that CFHT provide a comparison of APDs vs. CCD performance at the 2003 May SAC meeting.PUEO NUI
SAC encourages CFHT to continue to look for potential technical collaborative efforts from the participating member institutes. Preliminary contacts are quite constructive. In addition, Canadian SAC members will poll the Canadian community for interest in scientific side of the project and solicit science cases. Therefore, SAC repeats its request for a final science case document.SkyProbe
SAC is very pleased with the SkyProbe development. Recent progress includes replacement of the detector which provides better sensitivity although with some more complexity in the data analysis, due to some structure at the sub-pixel scale. SkyProbe is an extremely valuable facility and is now available at any time and for all instruments thanks to its new location on the telescope. CFHT should continue its efforts to improve the system with a two-color version.Elixir and the fringe pattern correction
The Elixir pipeline has been tested on data obtained with the WFI camera operated at the 2.2m at ESO. This camera is a mosaic of CCDs very similar to the MegaCam ones and with similar sensitivity to fringes in the far-red. Very successful results were provided, both in testing the robustness of Elixir to handle a large variety of data and in demonstrating that the effects of severe fringing can be very significantly attenuated by software. SAC is very pleased by the demonstrated progress made in dealing with these two difficulties as it provides confidence for the success of MegaCam observations.Gecko / UV mirror train
Considering that the UV train of Gecko is very lightly used and requires a significant amount of setup to be installed on the telescope, the question of decommissioning the coude UV train was examined by SAC. SAC also recognizes that the UV train requires the installation of the "old" prime focus upper end, i.e. the one presently used with CFH12K, which will soon be modified to accept WIRCam.OHANA
SAC recommends that the Gecko+UV train be decommissioned at end of semester 2003B. This should be advertised in the next call for proposals for semester 2003A.
In addition, CFHT should produce a summary of manpower requirements and detailed needs for the support and maintenance of Gecko+CAFE for 2002 November SAC meeting. The availability of Gecko in the Espadons era should be examined carefully at a future SAC meeting.
A document on the Ohana project update was sent to SAC. SAC supports CFHT tests of the Ohana injection module in August 2002, and the subsequent attempt to obtain fringes late in 2002B. CFHT should report the results to SAC at subsequent SAC meetings.
A science case is expected for the 2002 November SAC meeting. Additional documentation on operational scenarios and data reduction would help assist SAC evaluate the impact of Ohana on the operation of CFHT.
No report from the WIRCam Steering Group was received at that meeting. SAC discussed the implications of the UKDISS (UKIRT Infrared Deep Sky Survey) for the CFHTLS and in the context of a survey that may be carried out with WIRCam. SAC requests that the WIRCAM Steering Group discuss interest in a WIRCAM survey with community members. A call for ideas for WIRCAM observing programs must be circulated as soon as possible. A meeting of the Steering Group is foreseen for September 2002 to examine suggestions from the communities. A WIRCAM survey science program, if supported by the community, must be developed quickly and be delivered to SAC in advance of the November 2002 SAC meeting.
The MegaPrime project schedule presented
at the SAC meeting foresees first light for MegaPrime by early September.
However, SAC requests an update of the status of MegaPrime by August 15
in order to evaluate the possibility of the camera being available in 2003A.
With the present schedule, commissioning time will be relatively limited in the 2002B semester before the start of the CFHTLS.
While it is hoped that the CFHTLS can start as presently scheduled at the start of semester 2003A, SAC recommends that sufficient time be provided to CFHT staff in order to guarantee that the camera is fully operational before it is offered to CFHT users.
Finally, although it is not its mandate to define it and to interfere with the project team, SAC would like to be informed about the plans for MegaCam commissioning.
Since the last Board meeting several
actions have been carried out by SAC. At the request of the Board, a revised
version of the "Very Wide component" of the CFHTLS was prepared and submitted
by the MSWG (now superseded by the Steering Group). This document, received
by SAC and examined by the committee, was also sent to two external referees
who sent their reports before the meeting. In accordance with the referees
comments and after its own analysis, SAC recognizes that by incorporating
follow-up observations and multi-color observations (at the detriment of
the total area surveyed) the legacy value of the survey is increased very
SAC strongly recommends that each component of the CFHTLS now be allocated the number of nights requested in the CFHTLS Steering Group report. This includes 94, 162, and 194 nights for the Very Wide, Wide, and Deep Surveys with seeing better than 0.9", and an additional 16 and 8 nights for the Very Wide and Deep Surveys respectively with seeing worse than 0.9". The total of 450 nights with seeing better than 0.9", is within the limits previously set by the BoD. Final decision on the choice of filters and best observing strategy should be produced soon by the Steering Group.
In order to better advertise the CFHTLS and its scientific justification, SAC requests that the CFHTLS Steering Group produce a final merged, and carefully edited, CFHTLS proposal for the CFHTLS Web page once the final survey fields have been defined.
The next step in the preparation phase of the survey is the registration process, which is the responsibility of CFHT. A preliminary CFHTLS User registration page is already being prepared and was discussed at the meeting. SAC will be available for testing it and to provide feedback if required.
SAC has proposed a revision in the CFHTLS proprietary time policy for consideration by the CFHT Board.
A report about recent ngCFHT activities was given by G. Fahlman. Some interesting initiatives are being pursued both on the Canadian and French sides, mainly on Adaptive Optics issues. SAC encourages CFHT to retain an active role in discussions about ngCFHT projects, and encourages the continuation of all ongoing initiatives.