SCIENTIFIC ADVISORY COUNCIL OF THE
REPORT OF THE 51st MEETING
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:
MAY 15-17, 1997, TOULOUSE, FRANCE
KIR and OSIS detector developments
f/35 status, FTS, visitor instruments
AOB/Argus: status of the project
spectropolarimeter: status of the project
block and queue scheduling
long term future of CFHT
other items -
report on the Toronto meeting and discussion on scientific programs of
discussions on major choices
large IR detector situation
November meeting in Hilo on infrastructure and scientific niches in the
preparation of 1998 users' meeting
proprietary time - trans-Neptunian Objects
coordination of agencies on joint proposals
agenda for SAC next e-mail discussion
publication of SAC May report
next SAC and TAC meetings
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
CFHT TECHNICAL ACTIVITIES October, 1996 through April, 1997
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
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.
1.2.1 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
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
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.
1.3.1 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.
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.
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.
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.
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
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
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.
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.
CFHT's current operational detectors are :
We have on loan or use on an ongoing basis the following non-CFHT detectors.
STIS 2 (2k x 2k x 21 um thinned CCD)
Loral 3 (2k x 2k x15 um thick CCD)
Redeye Wide (256x256 x 40 um HgCdTe NICMOS FPA)
FTS InGaAs diodes
FTS InSb detectors
UH8k mosaic (8k x 8k mosaic of thick 2k x 4k x 15 um CCDs) (IfA)
MONICA (256x256 x 40 um HgCdTe NICMOS FPA) (Univ. de Montreal)
UBC1 (200x 4k 15micron thinned CCD) (Univ. of British Columbia)
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
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
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
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
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.
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.
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
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
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
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.
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
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
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.
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.
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
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.
2.1 Technical report: see 1.7.2
2.2 Report on the Toronto meeting and scientific programs
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
The design that has been followed lies between our options 1 and 2 from
the SAC November 1996 meeting. We urge that continued efforts be made to
make the field as large as possible and to pave it as fully as possible
with CCDs: this will ensure the greatest efficiency in observing and make
optimum use of the large investment in a new wide-field corrector.
It is important that the data processing development be pursued, and we
request regular updates from the Terapix consortium. We are pleased that
CADC will become involved in this effort and urge that a data-processing
workshop be held in the next few months, to define the work more closely.
A good opportunity for this might be in conjunction with the ADASS meeting
near Munich in September.
The Toronto science workshop has provided the following important design
UV throughput and sensitivity are very important: high sensitivity to =<3600A
the provision of an ADC is not required and for some programs is undesirable.
a grens/grism capability is of interest for some programs, but must incorporate
a 90deg rotation.
no parts of the camera should be moveable or rotatable. Grens rotation
may be achieved by exact pinning of the element; grism rotation may be
done by rotation within the filter holder.
image quality of =< 0.5" FWHM across the field must be achievable by
the camera system.
CCDs must have high QE over bands from ~U to I. Large dynamic range and
flatness are very desirable. Read noise of <10e is required. Pixel sizes
may be in the range 13-15microns. CCDs should preferably be mounted parallel
to the support spiders.
although there is no science-critical minimum field size for a new wide-field
corrector, maximising field size is important for observing efficiency.
minor vignetting by a fixed guide probe mask is acceptable.
a >= 6-position filter mechanism is required. The filter complement should
include 5 broad bandpasses and selected narrow band (100A) filters.
the data pipeline should be developed with CFH12K camera use, starting
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.
2 on large joint programs and data proprietary time:
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
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.
3. KIR and OSIS detector developments
see 1.7.1, 1.7.4 and Recommendation
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.
#4 on OASIS:
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
5. f/35 status, FTS, visitor instruments
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
This item was finally not discussed, due to the fact that the project seems
to have been on hold since the last SAC meeting.
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
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.
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.
9. Long term future of CFHT
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
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 ( email@example.com)
and/or Claude Catala, the Chair of the SAC (firstname.lastname@example.org)
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
Scientific drivers for UV wide-field imaging
Scientific need for an atmospheric dispersion corrector for Megacam
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
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:
KIR and OSIS detector developments: current status
AOB/Argus: status of the project
spectropolarimeter: status of the project
long term future of CFHT
Any other bussiness
report on the Toronto meeting and discussion on scientific programs of
technical report and discussions on major choices