SCIENTIFIC ADVISORY COUNCIL OF THE 
CANADA-FRANCE-HAWAII TELESCOPE

REPORT OF THE 51st MEETING
MAY 15-17, 1997, TOULOUSE, FRANCE

Members of the SAC present at this meeting were: Claude Catala (chair), David Hanes, Paul Hickson, John Hutchings (vice-chair), Gilles Joncas, Pierre-Olivier Lagage, Alain Mazure, Richard Wainscoat. Jean-Gabriel Cuby and Esther Hu had sent apologies. The open sessions of the SAC meeting were also attended by Pierre Couturier, Director of CFHT, Derrick Salmon, Director of Engineering, Dennis Crabtree, Head of Resident Astronomers. The agenda for the 51st SAC meeting was as follows:

AGENDA

  1. Director's report
  2. Megacam:
  3. KIR and OSIS detector developments
  4. OASIS acceptance
  5. f/35 status, FTS, visitor instruments
  6. AOB/Argus: status of the project
  7. spectropolarimeter: status of the project
  8. block and queue scheduling
  9. long term future of CFHT
  10. other items -

Recommendations

 Recommendation 1 on MEGACAM
 Recommendation 2 on large joint programs and data proprietary time
 Recommendation 3 on wide-field infrared imaging
 Recommendation 4 on OASIS
 Recommendation 5 on queue scheduling
 Recommendation 7 on archiving of CFHT data

1. Director's report (by Derrick Salmon, Director of Engineering)

CFHT TECHNICAL ACTIVITIES October, 1996 through April, 1997

General

The principal challenge for the technical staff during the past 6 months has been the maintenance of summit operations and on-going work on a large number of development projects, especially detector-related efforts, at a time of significant staff turn over. Nonetheless, the staff continued to focus on the work at hand and has achieved many noteworthy advances which are outlined below.

1.1. BUILDING AND DOME

1.1.1 Dome Shutter Cable Reel

Failure of the dome shutter cable reel resulted in damage to the shutter motor power cable. Timely removal and replacement of the cable prevented lost observing time. A sensor to monitor cable reel rotation in order to stop shutter motion if the cable take up action stops was added to prevent a re-occurrence of this problem.

1.1.2 Dome Skirt

The flexible weather seal between the dome and building tore after 10 years of service and could not be salvaged. A replacement skirt was custom manufactured and installed by the summit crew over several days with no loss of observing time.

1.1.3 5th Floor Instrument Prep Lab

Much of the background preparation work for the creation of the 5th floor instrument prep lab has been completed. The cable and signal routing from the computer and rear observing rooms has been determined and workbenches, connectors, cables and cabinets have been ordered.

1.2. TELESCOPE

1.2.1 Seating of Upper Ends

In an effort to resolve the problems which led to the upper end handling accidents in early 1996 we are generating as-built drawings of the mating surfaces of telescope top-end structures. We are in the process of taking detailed dimensional measurements of critical seating and locking surfaces for each of upper ends and for the telescope top ring. Specialized measuring jigs and readouts have been designed and fabricated in-house to take measurements at 5 degree intervals on these reference surfaces. Completion of the measurements during daytime operations, without interruption to the regular observing program, is currently underway despite time lost due to summit storms. At the moment we have taken data for the telescope top ring, the upper end handling ring, and the Cassegrain and IR upper ends. Data for the PF upper end are still needed.

Efforts to resolve clearance problems in the upper end locking mechanism progressed during a scheduled 3 day shutdown for inspection and maintenance of the second of four "birdshead" locking segments. An unusually tight interference fit between one end of this locking segment and the telescope, which led to segment mis-alignment and reduced mounting clearance, was resolved.

1.2.2 Prime Focus Bonnette

Precise offsets have been determined between center field and the TV guide probe. The offsets, including the effects of bonnette rotation, are now provided to the OA so that guide stars can be selected from the Hubble Guide Star Catalogue without vignetting the UH8k detector.

As part of the ongoing effort to improve the reliability of the systems at CFHT a study was undertaken to investigate the possible options for upgrading the Prime Focus Bonnette. A conceptual design has been prepared for a new control system which can be integrated in parallel with the existing system to reduce down-time and will integrate easily with the new TCS IV system. Further work is on hold pending MEGACAM developments.

1.2.3 Prime Focus Cage

A general purpose power supply system and associated cables and connector panels was fabricated to allow the Prime Focus cage to be fully operated while resting on the 5th floor.

1.2.4 Primary Mirror

The primary mirror was washed in February. In spite of cold weather, the washing went well. Reflectance at 670 nm increased from a pre-wash value of 82.8% to 85.8% after the wash.

1.2.5 The Telescope Control System

A calibration of the Prime Focus Bonnette has finally permitted use of the Guide Star Catalog and coordinated telescope/guider offsets at Prime Focus.

A study of prime focus bonnette and UH8K camera geometry showed that the then current non-cardinal mounting angle of the UH8k camera on the bonnette greatly restricted the available guider area and caused significant problems with vignetting. The camera mount was modified to align the ccd array with the x-y guide probe axes. A new Guide Star Catalog application was implemented and tested to indicate safe guiding areas.

Changes have been made in some TCS III sub-systems to better support both operation from an X-window terminal connection and operation as a service provider to TCS IV.

The speed and robustness of the communications link between the data acquisition system and TCS III has been improved.

1.3. INSTRUMENTATION

1.3.1 AO Bonnette

The AOB plus MONICA continue to work well. Work continues on the AOB session interface. A new temporary status display program showing only the APD (Wave Front Sensor detectors) counts and tip-tilt mirror position has helped improve observing efficiency. Work has been started on a new correction control form which will provide faster, more concise AOB operation. We have also developed the control system for the AOB Atmospheric Dispersion Corrector. It can now be used automatically for exposures in the visible. We continued calibration of the Wavefront Sensor to the sky using improved values of telescope coordinates.

Initial tests of the AO Bonnette with the 2x focal enlarger in Fabry-Perot mode had mixed results. The optics worked well, but the etalon did not. (See 3.8 Fabry Perot).

The Pro-Log controller software was upgraded to run the latest v2.22 DUCK operating system.

The possibility of borrowing a high-QE APD from the University of Hawaii for comparative QE studies is being pursued at a low priority.

1.3.2 MOS/OSIS

The new, high-resolution J&H IR grisms were received and tested in OSIS and are available for science.

Light baffles were designed, fabricated, and installed on both MOS and OSIS to seal light leaks around the relocated shutter. These baffles have been very effective at sealing light leaks in the volume between the grism box and the camera box on both spectrographs. However, small light leaks persist in other parts of the spectrographs. These leaks are being tracked down and eliminated now. We expect to have all light leaks sealed before the May OSIS and MOS runs.

New grism cells have been manufactured by DAO for MOS/OSIS. These cells permit changes of grism orientation when moving between MOS direct and ARGUS modes without removing grisms from their cells and should help to simplify instrument preparation. Most grisms are now in new cells. The new cells should greatly reduce the risk of breakage during setup.

The MOS mask slide has been reconjugated with the OSIS mask slide using the MOS mask slide rotation. This alignment will reduce setup times when switching grism wheels between the two instruments.

The replacement of DB with MS style connectors was completed and the documentation upgraded to reflect the changes. This has made the instrument easier to install and increased the reliability of the connections.

The central mirror carriage was removed, inspected and cleaned to solve a problem of intermittent motor drive failures.

The controller software was upgraded to the latest v2.22 Duck kernel for compatibility with the other Pro-Log controlled instruments.

1.3.3 OASIS

The OASIS spectrograph has undergone two sets of acceptance tests in Lyon in preparation for its arrival at CFHT as a Guest Instrument. The instrument performed well optically, especially the TIGER modes. Tests in the imaging modes initially showed problems which were mostly traced to errors in pupil location in the test hardware. Some indications remain that there may be residual image elongation at the edges of the 62mm module field.

The Observatoire de Lyon has been able to complete and to upgrade the control system over the past several months and instrument communications to the point where it is nearly ready for delivery. A final acceptance test is underway as of this writing. CFHT staff have obtained valuable experience with OASIS during this period. Acceptance tests were greatly facilitated by the loan of a 2k x 2k ccd system from DAO.

The User Interface software produced by the OASIS team at Lyon Observatory was installed at CFHT in an emulation mode to detect possible conflicts with the Pegasus environment. Unlike Pegasus, these Users Interfaces were written under the TCL/TK GUI toolkit. Ongoing integration of this software at CFHT continues prior to instrument delivery.

An artificial star assembly was designed, fabricated, and tested for use with OASIS and KIR and performed well during OASIS acceptance tests.

1.3.4 LAMA

Three auto-focus units have been tested briefly on LAMA; none have been successful. Another unit will be tested soon. Apart from the fabrication of MOS/OSIS masks, LAMA has been used extensively for mask fabrication for other instruments. Masks were generated for Rene Racine for the MONICA coronagraph mode, for pupil masks in the KIR camera, and for the lenslet pupil mask for the OASIS Tiger mode.

1.3.5 The Cassegrain Spectral Calibration Source ("Gumball")

Upgraded IR-transmitting optics have been designed and ordered for "Gumball". These will allow "Gumball" to be used with instruments mounted on the AO Bonnette as well as with MOS/OSIS. The design requires a calibration-specific lens in both MOS/OSIS and in the AOB.

Optics have been designed and ordered to add a Fabry-Perot-based calibration source to the Gumball. The finely spaced series of consecutive FP orders will provide improved spectral coverage in the visible over what is currently available with emission line sources.

The conceptual control system design for the upgraded Gumball has been completed and reviewed. Detailed control system design and hardware prototyping is now in progress with a goal of having the upgrade completed in time for the second OASIS engineering run this summer.

1.3.6 Gecko

An investigation was made into small misalignments between spectra from each of the gratings in the mosaic when a cross-dispersing grism is placed into the beam.
The investigation showed that this loss of alignment is a design feature of Gecko and does not substantially impair the overall image quality of the spectrograph. The study does indicate that the grating mosaic should be aligned using an order sorting filter rather than a grism if at all possible, however.

To improve shutter reliability we have started looking for latching solenoids to incorporate into the exposure meter and slit shutter assemblies as replacements for the latching shutters currently in use.

A new 100 mm Prontor shutter has been modified and mounted at the detector environment. This shutter is large enough to avoid vignetting the UBC CCD and has been modified to limit heat dissipation. The shutter worked well during the last coude run and for recent tests and setups.

The GECKO controller software was upgraded to run the latest v2.22 DUCK operating system.

1.3.7 FTS

New IR2 beamsplitters (2.8 fm to 5.0 fm) were ordered and an initial delivery received. Unfortunately these beamsplitters had a large absorption region near 2.9 fm. The vendor is currently developing a second set since the first do not meet specification.

1.3.8 Fabry Perot

During tests of the FP mode for the AO Bonnette we were unable to control the spacing for etalon #3. The etalon was returned to Queensgate for repair. Repairs are complete and the etalon is now back in service at CFHT. The problem was traced by Queensgate to age-related internal contamination of one of the electrodes in these sealed units.

1.3.9 TIGER

After consultation with L'observatoire de Marseille, the TIGER spectrograph has been packed and will be shipped back to Marseille in the near future.

1.3.10 Distributed Control Systems

In an effort to control costs and to insure that new instrument and facilities developments at CFHT utilize modern and reliable control systems we have undertaken a study of currently available industrial distributed control "fieldbus" systems. We plan to specify one of 2 contending field busses for inclusion in the MEGACAM project.

1.4. DETECTORS

CFHT's current operational detectors are : We have on loan or use on an ongoing basis the following non-CFHT detectors.

1.4.1 STIS 2

STIS2 has continued to perform extremely well with constant use. Readout time was improved early in the semester so that the full 2kx2k image is read out in 2.5 minutes (versus 6 min previously) with no loss of image quality.

1.4.2 UH8k

The UH8K mosaic has been improved by IfA with the addition of a more reliable shutter, and improved data acquisition software. Recent observing runs have been without incident.

1.4.3 Redeye Wide

In November the vacuum valve on Redeye was damaged when the turbo-pump was not disconnected before lowering the pump from OSIS with the forklift. To prevent future incidents and promote more efficient operations, staff training is being provided in the care and handling of dewar and detector control systems.

The Redeye vacuum valve has been repaired. The dewar has undergone multiple vacuum and thermal tests and appears to be solid. A new preamplifier which provides detector-limited performance has been added. Optimized DSP code reduces readout time from 4 to 2.5 seconds.

1.4.4 Loral 5

Loral 5 is a thinned 2k x 2k x 15 fm CCD currently under final assembly and test. System development was delayed while we procured an engineering device from Gerry Luppino at IFA and had it packaged by Mike Lesser at UofA.

The dewar is fully assembled, the CCD controller is wired and the DSP code is under test with waveform probing at the device socket. The engineering array has been mounted and successfully read out. Loral5 is configured for single or dual output readout. It is the first CCD developed at CFHT to provide this feature. It is expected that the dual port readout will provide a reduction in readout time with no performance penalty.

Loral5 is currently scheduled for mid-May completion.

1.4.5 EEV 2K x 4K

The EEV 2k x 4k is a thinned 13.5 fm pixel CCD. The device is on order and is scheduled for delivery in November, 1997. An agreement is being developed with UBC to prepare a CFHT dewar for this detector during the summer of 1997.

1.4.6 Detector System Software

Detector on-line archive

A detector on-line archive has been implemented to provide in-house Web-based logging of detector system activity, to improve system reliability, to provide a universal location for technical documentation, to provide access to troubleshooting procedures, and to store sample images for all system. This is a process under development and will continue to grow with time.

G3V4 Detector Host Software

The long-needed upgrade of the detector host software is under final testing and nearing completion. It will first be implemented on KIR. The G3V4 system is a total rewrite of the previous CCD host acquisition software. Eventually the control of all single CCDs and IR Focal Plane Arrays (FPA's) will be based on G3V4.
G3V4 is based around a hardware architecture which, unlike G3V3, employs a VME-based image memory. This hardware architecture allows full DMA access to image memory by the SDSU CCD controller. This point is fundamentally important in that it removes the real-time pixel handling requirement of the SPARC1E CPU. This means that if the CPU is occupied for any reason during an exposure, no image data is lost! This single issue was the Achilles heel of the current G3V3 system.

In addition to implementing VME memory, there has been a restructuring of the software architecture to reduce complexity which was formerly present in G3V3. CCD exposures should no longer "hang". This scenario would typically require an individual from the Detector or Software Group to log on as root, to kill and then restart the CCD Host.

One of the biggest weaknesses of G3V3 was an inability to reliably handle ABORT exposure requests from the observer. G3V4 provides consistent ABORT response by implementing an exposure state timer in the CCD Host so that it knows, in a coarse fashion, when readout will begin. It therefore can handle the abort requests in the appropriate fashion depending on whether pixels are flowing or not.

Another weakness in G3V3 was the inability to respond to unsolicited messages from the SDSU CCD Controller. When the SDSU is power-cycled or when there is a hardware reset, the SDSU CCD controller (appropriately) sends a message up the fiber to the CCD host to notify the host that a system reset has occurred. This input is designed to be an interrupt for the host to take the appropriate action of reconfiguring DSP code, checking system state, etc. In G3V3, this signal used to cause the system to hang and typically require the server to be killed and restarted.

G3V4 now logs the event for system records and takes the appropriate action automatically to reconfigure the system and continue operation. G3V4 also provides added security in the form of software and hardware ID checking. There is a larger set of system information available to the user for development, debug, and datalogging. G3V4 will be complete for KIR in June, with porting to other detectors to follow in the summer and fall of 1997.

Det I (Detector Interface Software)

Det I is a powerful command-line user interface and toolkit which provides valuable engineering access to the detector host image acquisition system. Det I is under final development and test.

CFHT detector development has long labored under the weight of Pegasus as a development environment. In fairness to the Pegasus software architecture, Pegasus was designed as an observing tool, not as an engineering development tool. What was needed was a lean, yet powerful set of tools which allowed the efficient manipulation of the detector computer and provided low-level access to the SDSU controller. Pegasus did not meet these needs; Det I does. Det I provides complete exposure control. Det I can be run directly on the CCD host or remotely, thereby removing the need for a session host computer for detector system development and test. It provides error logging and recovery, a powerful set of DSP code development tools for downloading and verification of code in all 3 SDSU boards (VME Interface, Timing and Utility), low-level command access, and more.

1.4.7 Detector Labs

Residual Gas Analyzers (RGAs) have been installed at both the Summit and Waimea to provide valuable information on the vacuum integrity of CFHT cryostats.

An expanded clean room facility at Waimea is being designed to handle the needs of the large format cameras under development.
Detector system documentation has been improved. Currently available are initial troubleshooting procedures (others under development), standard practices for CCD handling, improved system labeling, and waveform and DSP code documentation.

1.5. COMPUTERS AND SOFTWARE

1.5.1 Data Reduction Facilities

Several improvements to the data reduction facility have been implemented to increase computing power, data transfer rates and to facilitate equipment maintenance. The large amount of data produced by the UH8K CCD camera compelled us to increase data storage areas and the computing power of the main Ultra Sparc 2, Kuanalu, serving the scientific staff in Waimea. Kuanalu was upgraded to use dual processors. Its memory was increased to 768 MBytes with direct access to a disk farm of more than 75 Gigabytes. A second Ultra Sparc has been designated to serve visiting observers willing to spare some time in Waimea to reduce their data. To facilitate maintenance and to upgrade the network environment, a third Ultra Sparc is being prepared to replace the old Sun 690 servers Uwila and Nuilolo.

1.5.2 GenX

GenX is the current name for the next generation CFHT observing environment to be used in the era of large detector arrays. GenX is an attempt to develop an integrated observing environment which will encompass telescope control, instrument control, detector control, data handling, and the observing user interface. The GenX project has been in the initial concept stages for the past 6 months. Meetings and discussions aimed at preliminary project definitions are underway.

1.5.3 Pegasus

We started upgrades to the communications and client/server infrastructure in Pegasus (needed, for example, to support AOB properly), and have started preparing Pegasus for HP operating system upgrades.

1.5.4 Data Acquisition System computers and network communications

We began the upgrade of the DAIC HP systems' operating system from HP-UX version 9 to version 10.20. We have arranged to upgrade the system disks at the same time. We installed a switched, twisted pair network at summit, increasing the effective network speed to support 100 M bit/sec communication.

1.5.5 Summit to Waimea communications link

The Hawaiian Telephone Company recently finalized the installation of the optical fiber link between Mauna Kea and Waimea, giving us access to a DS3 (45 Mb/sec) link to the summit. At the moment we are in the process of studying and examining alternative approaches for connecting to the fiber as well as evaluating the associated hardware equipment offered by a range of manufacturers.

1.5.6 PC-based systems

Following discussions with staff, CFHT has a list of standard PC-based tools which the company requires and supports. Based on these standards, PC systems are being upgraded to the Windows 95 operating system and HUMMINGBIRD MAESTRO networking software.

1.5.7 FOCAM - Fabry Perot

A focam plus Fabry-Perot Pegasus session was developed, allowing use of the Fabry Perot etalons in the AOB focal enlarger.

1.6. MAJOR PROJECTS

1.6.1 TCS-IV

Many of the basic TCS-IV functions have been implemented and tested. Advanced features are in progress. The project is still targeted to be fully operational by the end of 1997, although the formal complete date has been moved to April 30, 1998 due to staffing problems.

Successful engineering tests have been made by performing daytime engineering whenever possible. Adverse weather conditions have resulted in about half of the daytime engineering opportunities being unusable. Pointing and tracking, bonnette control, auto-guider, and automatic dome control have all been used successfully, although not in their final form.

Work has started on the first iteration of the end-user Graphical User Interface. Observing Assistants' input is being used during GUI development. Prototype GUI's are being developed to test control ideas, and further solicit user input.

An automatic guider has been incorporated into the system. It uses a commercially available VME frame grabber to interface our existing analog television cameras to TCS IV. Autoguider implementation required the porting of an available image acquisition library and some custom VxWorks and EPICS code. Initial tests of the guider on the sky have been encouraging.

During an initial transition period TCS III is providing dome and bonnette services for TCS IV.

A serial I/O sub-system has been implemented, and a software interface to TCS III is now operational over a dedicated RS-232 link.

At a very low level in TCS IV, commands which will eventually go to TCS IV sub-systems are now routed to TCS III. This level of modularity will permit easy replacement when permanent TCS IV hardware solutions are developed. For the dome and cassegrain bonnette this permits us to easily make the transition from TCS III to IV and back with a minimum of disturbance. Once TCS IV is operational full-time, we will switch to new hardware and software interfaces on the TCS IV side which will permit us to concentrate on one sub-system at a time, and make testing safer.

The prime focus bonnette's final solution is less well known. Use of TCS III permits us to have PFB control while its control system rebuilding options are decided. Again, it will be ported to TCS IV only after TCS IV is fully operational, and perhaps not until a PFB control system rebuild is completed.

One of the major features of TCS IV is the virtual main and guide telescopes. The design has been well worked out, and initial implementation is completed. Unfortunately weather prevented us from testing this feature at cassegrain. The first nighttime tests at prime focus have been successful, but have also indicated that additional work needs to be done in the area of the bonnette pointing models and semi-automated calibration procedures.

1.7. NEW IMAGING PLAN

1.7.1 KIR

Optical design and fabrication are complete. The cryostat will be finished at IR Labs in late April and will be shipped to the University of Montreal by the start of May. Once at the University of Montreal, vacuum integrity test will start followed by assembly of the optical bench and filter wheel subsystems. Full system integration is scheduled for May, with acceptance testing by University of Montreal and CFHT staff in Montreal near the end of May. Delivery to CFHT is scheduled for June.

KIR employs a new preamplifier design, a modified SDSU acquisition controller, a VME-based image memory with ALU for inline frame-based multi-sample readout, as well as redesigned detector acquisition system software.

The KIR 4 channel DC coupled preamplifier has been designed at CFHT to provide detector-limited performance for both the HAWAII (KIR, OSIS-IR), and NICMOS (Redeye W) arrays. A total of 5 4-layer circuit boards have been fabricated. The first amplifier is assembled and tested and will be used for KIR. The second board is being assembled for use with Redeye W and a third will be used with OSIS-IR. A fourth unit will be assembled as a spare.

The KIR acquisition software is nearing completion in all areas; DSP code, detector host software (G3V4), Filterwheel Control, and the Pegasus session software are all complete or nearly so. Additional capability has been provided in the form of a command line interface and extensive diagnostic toolkit (Det l) to support engineering and low-level access to system operation. See G3V4 and Deti descriptions for further details.

1.7.2 MEGACAM

A MEGACAN kickoff meeting with participants from CFH, CEA, DAO, OPM, OMP and the Division Technique de INSU was held at the CFHT headquarters on March 12 and 13, 1997. The minutes of this meeting are provided in a separate document.

Briefly, the kickoff meeting concentrated on project hardware issues. Discussions between CFHT and CEA on computer and software systems issues will start this spring.

The 17 work packages identified for MEGACAM were divided between CEA, DAO, OPM and CFHT. Apart from the selection of work packages, the principle points of discussions at the meeting were design requirements for the wide field corrector, guider issues, shutter and filter issues, image stabilization, the prime focus environment, instrument control, and the project development schedule.

The development schedule calls for CFHT & CEA to finalize details of the control system as quickly as possible so that CEA's organization can start work. DAO, on the other hand, due to commitments to Gemini, will be unable to participate in even conceptual design reviews until November, 1997. The schedule calls for completion at the fully populated camera at CEA by the summer of the year 2000, the completion of the WFC and guider systems at DAO by the start of the year 2000, and the completion of a new upper end at the telescope by CFHT by the spring of 2000.

The request for quotes for the camera's CCDs has been developed in a collaboration between CEA and CFHT. A final document has been agreed upon. It is now ready for submittal to COMA and to a list of potential suppliers. Responses are requested by June 27, 1997. Vendor selection could be as early as August, 1997.
Refinement of Wide Field Corrector designs continue. Final selection of Wide Field Corrector design and related options will be made after the Toronto Science meeting.

1.7.3 CFH12K

Work at CFHT on the CFH12k detector array has been functionally divided into two projects : Hardware development and Software development.
The contract for the purchase of IfA's share of the consortium CCD's and wafers, and for thinning of the second batch of wafers has been submitted to and approved by COMA.

At the IfA, the cryostat has been fabricated, the shutter has been fabricated, and the filter wheel is under design. The array mount and CCD electrical and thermal interconnect and controls are being designed. The CCD controllers are on order from SDSU and are due to be delivered to the IfA in May.

The initial front-side Lincoln Labs CCID-20 devices have been received at IfA and are undergoing initial tests. Preliminary testing has revealed less than 1e read-noise for the prototype front-side device! These devices are potentially the best CCDs yet produced for astronomical use in terms of size, readtime, and image quality. The second wafer set has been thinned and is ready to be cold-probed. We expect to receive the full device set by mid-summer, for focal-plane population at the end of summer and first light in October.

Development of control and user software has started at CFHT with the porting of UH8k software to Solaris. The definition of the CFH12k software is underway and is expected to incorporate quick-look NOAO image display utilities, and the extended FITS file format.

1.7.4 OSIS-IR

The OSIS-IR is a large format (1kx1k) IR camera for OSIS. The OSIS-IR contract is under final negotiations with the University of Montreal. KIR project efforts have delayed the optical design effort required for final cost estimates necessary for the final contract. All OSIS-IR technical issues have been raised and resolved. OSIS-IR is expected to take 6 months from final contract to delivery which is expected at the end of 1997.

1.8 . SAFETY

Development of the CFHT Safety Program was considerably impeded by Rod Hendrix's departure. We now have a new summit manager, Larry Millard, who has extensive experience with OSHA requirements. We expect to re-vitalize the implementation of the safety program within the next few months.

1.8.1 Inspection by HIOSH

We invited the Hawaii Occupational Safety and Health (HIOSH) Consultant and Training Branch to survey the Waimea Headquarters Facility and to provide a hazard assessment. Ten serious hazards were identified. All violations have been corrected. Documentation and notice of corrections were filed with HIOSH by their required due dates. Most of the hazards were related to electrical wiring where extension cords were being used permanently to power devices. Trip hazards, cluttered work space, and blocked fire extinguishers in the automotive and carpentry shops required considerable re-organization effort which has resulted in a much more orderly workplace. All flammables have been placed in approved flammable storage cabinets. Efforts to create a covered storage space outside the building is continuing.

1.8.2 Observatory Fire Alarm

Moisture which entered the summit fire alarm system from observing floor condensation resulted in a system failure. The effected circuitry was cleaned and troubleshot by persistent CFHT staff with reluctant help from the manufacturer. The system is outdated. Spares are not readily available. The alarm system is now fully operational following maintenance and the replacement of some sensors.

1.8.3 Safety training

A presentation was made to the full staff on procedures established by Mauna Kea Support Services for medical evacuation from the summit. In addition, education on basic summit safety, and observatory evacuation was included.

Summit daytime staff received initial training on the use of our Self Contained Breathing Apparatus (fire rescue air breathing equipment) by a representative from the manufacturer.

2. Megacam

2.1 Technical report: see 1.7.2

2.2 Report on the Toronto meeting and scientific programs of Megacam

The Megacam project has been the subject of a special SAC email discussion in February 97. A report on this discussion is appended to the present report (Appendix A). Moreover, a science workshop in Toronto in May was dedicated to this project, and extended discussion took place at this SAC meeting. We have reviewed the project thoroughly, and re-assessed its scientific viability in the light of these discussions and the design progress in the past few months. Strong scientific interest was expressed in the Megacam project at the Toronto workshop. In view of the outcome of these various discussions and workshop, the SAC wishes to make the following recommendations (R1, R2 and R3):

Recommendation #1 on Megacam:

The SAC continues to endorse the Megacam project and notes the following points.

 Recommendation 2 on large joint programs and data proprietary time:

The use of CFH 12K camera, and later Megacam, together with a data-delivery pipeline, will require new approaches to time allocation and data rights. SAC proposes the following model, to be initiated for semester 1998 I, particularly for CFH 12K camera, but applicable to any instrument.

Time for large joint programs will be contributed in the usual proportions by all participating agencies, by joint agreement between CTAC, CFGT, and UHTAC, on the basis of the same proposal sent to all agencies. In the Megacam era, we suggest an upper limit of about 30% of all nights be assigned this way. This number may be revised as needed. Such programs may typically extend over several semesters subject to review each semester.

Starting in 1998, SAC proposes that data from such joint programs will be available to all signatories of the proposal, via the pipeline, immediately. This may include students, postdocs, or other colleagues connected with the signatories, as agreed within the consortium.

SAC proposes that data will be proprietary for a period of one year after delivery from the pipeline, unless an extension is requested within the proposal, and approved by the joint TACs. SAC proposes that data from other observing projects approved by any agency will be proprietary for a default period of one year after acquisition. Extensions may be applied for in the proposal, and will be subject to individual TAC approval. SAC propose that all non-scientific data such as bias, dark, or flat-field frames have zero proprietary time.

Proposals may be sent to any TACS for science requiring immediate or early access to proprietary data. This may be approved for science goals which are distinct from the approved program of the observers.

Recommendation 3 on wide-field infrared imaging:

The SAC recognizes the very high scientific value of deep wide-field imaging in the near infrared from 1.0 to 2.5 microns.

The SAC learnt that the OSIS IR camera can, with minor design modifications, also be used for imaging directly at the f/8 focus (0.2 arcsec pixels, 3.4 x 3.4 arcmin field-of-view). These modifications will likely increase the camera cost by a few thousand dollars, and will require approximately 4 weeks of additional design time. The SAC felt that ability to use this camera for imaging directly will add valuable (and presently lacking) IR imaging capability to CFHT for the near-term future 1998-1999.

The SAC therefore recommends that the OSIS IR camera design be immediately modified so that this camera can also be used directly at the f/8 focus for imaging in the 1.0-2.5 micron range.

The need for wide-field infrared imaging capability to complement Megacam was identified at the Megacam workshop. For CFHT to be competitive in near-IR imaging beyond 1999, a larger IR camera must be developed . A camera with 2048**2 pixels (7-10 arcmin field-of-view) is the minimum requirement, a 2x2 array of 2048**2 detectors is preferred. The SAC recommends that CFHT continue to explore all possible avenues to participate in the development of large-format near-infrared cameras, and report to the SAC at the Nov. 97 meeting.


 

3. KIR and OSIS detector developments

see 1.7.1, 1.7.4 and Recommendation 3.

4. OASIS

Recommendation #4 on OASIS:

The SAC welcomes news of the imminent arrival of OASIS at the CFHT and anticipates its acceptance as a guest instrument. The SAC recommends that the OASIS science team be granted five nights of commissioning time.

5. f/35 status, FTS, visitor instruments

The director informs the SAC that CFHT has been experiencing difficulties with the f/35 focus and one of its related instruments (FTS): (1) the mirror was damaged in 1996, (2) key personnel involved in the maintenance of the FTS have left, and (3) the reduction in manpower and of money available for operation has taken its toll. There is thus little FTS expertise left at CFHT and the many ongoing projects make it difficult to recreate that expertise. CFHT cannot prioritize the f/35 focus anymore. There is no manpower for preventive maintenance and a lack of technical knowledge to repair quickly any breakdown. Observations are now being carried at the astronomer's risk.

Therefore the director will ask at the next SAC meeting for a priority list for the ongoing projects and for a decision on the de-commissionning of an instrument since a high degree of versatility cannot be supported any more at CFHT. At the staff level there is a perpetual conflict between the time that must be allocated to development and the one necessary for the operation of the telescope. In summary, the executive wants to favor the instruments most often used on the telescope.
In response, the SAC wants to see at the next meeting a clear and quantitative study of the efforts needed to maintain the instruments versus their use and demand by the communities and the importance of their scientific returns. For example, the uniqueness of FTS in the BEAR mode has to be taken into account.

6. AOB/Argus

This item was finally not discussed, due to the fact that the project seems to have been on hold since the last SAC meeting.

7. Spectropolarimeter

C. Catala presented the current status of this project. The optical design of the echelle
spectrograph is almost complete and a full mechanical study will be undergone shortly.
Funding will be requested to INSU and NSERC in the fall of 97. Additional funding will also be
requested to CFHT.

8. Block and queue scheduling

Following a presentation by CFHT executive of a proposal for queue scheduling and service observing, and after a discussion on these issues, the SAC wishes to make the following recommendation: 

Recommendation #5 on queue scheduling:

The SAC recognizes that queue scheduling has the potential to provide a substantial increase in observing efficiency for many types of programs. However, we also believe that development of an appropriate scheduling algorithm will be a complex task and that not all programs may be suitable for queue scheduling. We therefore recommend that CFHT examine in detail the observing programs and atmospheric records for the past three semesters in order to make an assessment of the gains that would have been realized had queue scheduling been in effect, and to develop an effective scheduling algorithm. Assuming that this process is successful, we recommend that a trial be made in which limited queue scheduling is introduced beginning in semester 98II. During this trial, queue sheduling would be in effect for programs employing AOB and the CFH12k instruments. Based on the results of this trial, the SAC may then recommend continuation or expansion of queue scheduling at CFHT.

9. Long term future of CFHT

In November of 1996, the SAC received a first report from the sub-committee established to consider the long-term future of the CFHT. (The sub-committee, chaired by David Hanes, draws its members from all three communities, and includes: Bob McLaren from Hawaii; Doug Welch and Simon Morris from Canada; and Guy Monnet and Daniel Rouan from France.) With their November report, the sub-committee had requested that the CFHT Executive commission a first engineering study to address the feasibility of mounting a segmented-mirror telescope of large size (12-16 metres) on the present CFHT pier, and to estimate the salvage value of the present telescope and the down time which would be imposed by such a conversion.

The requested report, prepared by Walter Grundmann, was presented to the CFHT Executive and the sub-committee in March of 1997 (and through them to all SAC members and other concerned parties). While the conclusions are the result of provisional engineering estimates only, based on straightforward scalings from the Keck and Gemini experience, the implications seem to be that the present pier might well prove adequate for the support of a 12-metre segmented-mirror telescope, but that a 15-metre might be problematic. In either case, closure of the facility might be expected for up to four years.

The SAC considered the contents of the Grundmann report but also engaged in a wider discussion along a variety of lines. Perhaps most important of these is the observation that any large-scale change to the CFHT must be in response to demonstrable scientific need and with the expectation of realising significant gains in scientific performance. Committee members Hanes and Welch are continuing their preparation of a case in support of a larger facility on the CFHT site, and will consider the matter further in the sub-committee before reporting again to SAC.

Other issues were addressed, including the foreseeable needs for a large northern-hemisphere telescope for the French community in the decades to come and the specialised nature (if any) of such a facility. One aspect of the original report by the sub-committee (November 1996) had been the identification of the exciting scientific potential of working in the 3-5 micron wavelength regime, a prospect which remains scientifically appealing but which may become uncompetitive from the ground given recent NASA discussions and endorsement of the New Generation Space Telescope (NGST). The sub-committee will continue its deliberations in the light of these possible developments.

The CFHT users are encouraged to contact David Hanes, the Chair of the sub-committee ( hanes@astro.queensu.ca) and/or Claude Catala, the Chair of the SAC (catala@obs-mip.fr) to express their views on these issues.

David Hanes, the Chair of the sub-committee, was joined by the CFHT Executive in acknowledging the very fine report prepared by Walter Grundmann.

10. Other items

10.1 Large IR detector situation

See Sect. 2.2. and Recommendation 3

10.2 November meeting in Hilo on infrastructure and scientific niches in the 8m era

A meeting will be held in Hilo in early November 97 about infrastructure and scientific niches for the telescopes on Mauna Kea in the 8m era. Participation of CFHT staff and possibly SAC members to this meeting is strongly encouraged.

10.3 Preparation of 1998 users' meeting

The scientific organization of the 1998 users' meeting will be initiated via an e-mail discussion among SAC members in September 1997. The chairman of the Scientific Organizing Committee is John Hutchings. We have identified three major sessions: (1) scientific results from CFHT, (2) new and planned instruments, (3) long-term future of the CFHT. Following this first e-mail discussion, a more detailed scientific program for this meeting will be defined at the SAC meeting of November 97.

10.4 Proprietary time

See Sect. 2.2 and Recommendation 2

10.5 Trans-Neptunian Objects

The SAC was informed of the objections raised after the use of some recently acquired UH8k images for the search of fast moving objects. The SAC does not wish to be involved in this particular problem, but proposes a general policy about the use of CFHT data for other scientific purposes than those included in the PIs' proposals. This suggestion is included in recommendation R2 (Sect. 2.2).

10.6 Coordination of agencies on joint proposals

See Sect. 2.2 and Recommendation 2.

10.7 Agenda for SAC next e-mail discussions

We have identified a need for a possible SAC e-mail discussion in June 97, about the appropriate route to follow for the procurement of the Megacam CCD chips. The CFHT executive will contact the SAC chairman in due time to organize this consultation. Another SAC email discussion will take place in September 97, about the scientific preparation of the 1998 users' meeting.

10.9 CFHT archives

Recommendation 7 on archiving of CFHT data

The SAC reaffirms the need for good performance archiving of CFHT data. The SAC acknowledges the valuable work done at CADC for CFHT data archiving and strongly encourages the CFHT team to collaborate actively with CADC and the agencies to continue their support. 

10.10 Next SAC and TAC meetings

At the time of editing this report, it was decided that the next SAC meeting will take place in Waimea, on Oct. 30, 31, Nov. 1, 1997. The TAC meeting will be held on Oct. 30, after the end of the SAC meeting session that day. This date may be revised, should it create a conflict with the schedule on the next CTAC meeting. 

 

APPENDIX A: REPORT OF THE SAC EMAIL DISCUSSION FEBRUARY 97

The SAC held an e-mail discussion on Feb. 3 - 7, 1997. The agenda of this discussion was:
  1.  Scientific drivers for UV wide-field imaging
  2. Scientific need for an atmospheric dispersion corrector for Megacam
  3. Agenda for the next SAC meeting (May 1997)

1. Scientific drivers for UV wide-field imaging

There is a strong scientific case for UV wide-field imaging. By UV here, we mean down to at least 370-360nm, and possibly below. This scientific case is summarized in a report appended to this text.

All efforts should be made to provide such a capability with good throughput for Megacam. In particular, the specs for the CCDs should include a reasonable QE down to at least 370nm.

There seems to be technical solutions, for instance based on hybrid BK-7 / fused silica for the corrector. The quantum efficiency of the RGO 2kx4k EEV chip is also quite encouraging.

The access to the UV should not compromise significantly the quality of the images and the throughput at redder wavelengths. We feel that we do not have enough information, both on technical and on scientific grounds to provide a more quantitative guideline. We request such information when available (i.e. after the Megacam science meeting for the scientific part) to review this issue.

We will also need a better understanding of the cost of the UV access (including corrector and CCD), and will need to review the project when more information is available.

2. Scientific need for an atmospheric dispersion corrector for Megacam

We have identified some scientific merits for an ADC for Megacam (for instance pushing the limiting magnitude for point source work at U and B bands), but they are marginal. Most of the science programs which require an exquisite image quality are in the red where the effects of atmospheric dispersion are smaller than the expected image quality, while the programs identified so far requiring imaging in the B and U band, which would benefit from an ADC, are mostly of the photometric type on extended objects, and in general do not require the best image quality.

However, Megacam is supposed to be still operational in 10 years from now, and it is difficult to decide what observations will be needed by then. It is possible that excellent image quality in B or U will be required by future scientific programs, unidentified today.

On the technical side, we still need further studies to determine what level of degradation (if any) is produced by a properly designed ADC in the red wavelength range. We also need a proper cost estimate for the ADC, including its optics, mechanics and control system, as well as an estimate of the savings that an ADC will bring by facilitating the guiding.

We therefore conclude that it is desirable to keep the option for an ADC in the preliminary design of the corrector, but that this option is of lower scientific priority. The final decision to include it or not will depend on one hand upon the feasibility of an efficient ADC with unsignificant impact of imaging at red wavelengths, and on the other hand upon budgetary constraints.

3. Next SAC meeting

The next SAC meeting will be held in Toulouse, on May 15,16,17, 1997. The preliminary agenda for this meeting is:
  1. Director's report
  2. Megacam:
  3. KIR and OSIS detector developments: current status
  4. OASIS acceptance
  5. AOB/Argus: status of the project
  6. spectropolarimeter: status of the project
  7. block scheduling
  8. long term future of CFHT
  9. Any other bussiness 

    10. Appendix A: Interim Science Considerations for MEGACAM Performance - Jan 97