CFHT Observatory Manual
Section 3 - THE OBSERVATORY
show the floor plans of each level in the dome. (under construction)
Live video images can be
received at various locations in the building. The following are some
Channel 03: TV guiding camera (Cass and Coude)
Channel 06: Dome slit low light camera
Channel 07: West view of inside dome
Channel 08: Main entrance door
Channel 09: East view of inside dome
Channel 10: South view of telescope
that, in keeping with staff safety requirements, hard hats should be
at all times when working in the dome area and main hatch area.
- Dome Cooling and
The temperature of the
dome area is controlled via a series of sensors distributed throughout
the dome and coupled to the
building glycol system. Cooling coils are
in the concrete floor. Ventilation of the dome is controlled primarily
the motorized louvers at the top and bottom of the dome structure.
vents are normally left open to allow air to flow
between the skins of
the dome and closed when weather conditions require sealing off the
Controls for these louvers
are located on the mezzanine catwalk, inside
In addition to the
louvers, there are two fan units which can be controlled with a timer
switched on and off manually.
These units are also fitted with glycol
coils and capable of delivering chilled air to the dome area. The units
on the N.E. portion of the dome, (directly over the freight
elevator) and also on the S.E. portion of the dome, (directly over the
- Dome Shutter and
The dome shutter is an
"up and over" type shutter, consisting of 12 hinged sections and driven
by eight motors on a rack and
pinion drive system.
The control of the
can only be done from the dome catwalk.
The windscreen is a
driven device consisting of a series of steel partitions which store
in concertina fashion
at the base of the closed shutter. It is a
lowering device and the sections tend to hang up in high wind
Two slack cables have been recently fitted which prevent the down
of the windscreen in that case. When it happens, the
dome has to be
to take the windscreen away from the wind and the cable driven up
attempting to cover the
windscreen. Like the shutter, the windscreen is
controlled from the dome catwalk.
- Seeing Conversion
Since a 1 C air
differential at the level of the primary mirror gives a seeing
of about 0.5 arcsec, strict
control of the telescope
is essential. This is done chiefly by maintaining the dome floor
temperature of the oil used in the telescope's hydrostatic
near the mean midnight outside air temperature of 0 C. This
is occasionally shut down,in particular during summit snow storms.
inclement weather, observers should
confirm with the
operating the telescope that the chilling system has been restarted.
Power dissipation in
is generally kept low. In particular, the sodium vapor flood lamps on
5th floor are turned off
when not needed.
Similarly, all doors opening
onto the observing floor, including those leading to the elevator,
at all times. Generally,
the dome slit is closed during the
but may be opened on occasion for engineering purposes.
equipment can help reduce power dissipation near the telescope by using
the AC/DC power sources
provided at the various
foci in lieu of
room is located on the fourth floor, directly to the left upon exiting
the elevator. A large console
contains the controls and
for controlling the telescope (Operator's section at right) and most
(Observer's section at left). The guiding TV's can
be viewed by both the Observer and the Observing Assistant.
audio system is also incorporated, and you can bring your favorite
tape or CD. Copies of a variety of useful
handbooks can also be
as the SAO Star Catalog, The Astronomical Almanac and the Observer's
Observing Room (4th
The room is located
the control/observing room, and adjacent to the computer room on the
floor. It contains 19 inch
racks for auxiliary
instrumentation cabling connected to the two foci and electronic
Many visitor instruments are also operated from here. An observer's
console provides TV guiding monitoring, an intercom equipment for
with the Observing Assistant, and workstations connected to the CFHT
- Remote Observering
are availible for remote observing from the CFHT Headquarters, and
may be done by
identical observing sessions from the
comfort of the Waimea office. Observers interested in Remote
should contact their
(2nd and 3rd Floors)
There are two
available on the second floor for the set-up and testing of
Room 209 (IP1) is best suited for
vacuum and cryogenics work. A pumping
station comprising a turbomolecular pump and a pair of Vacsorb pumps is
evacuating cryostats. The room is also equipped with an
helium leak detector.
For pumping on
are two systems each using a Sargeant-Welch Model 1397 mechanical pump
These systems are also connected by plastic tubing
to the Infrared and Optics Lab (Room 209A) and to a manifold at the
focus of the telescope. The two pumps can be used separately or in
IP1 also contains a
and various cryogenic accessories such as small dewars and a helium
tube. The standard
vacuum hardware at CFHT is Klamp Flange or Alcatel
10 or 16.
The second instrument
room (IP2) comprises the combined area of Rooms 205 and 206. A CAMAC
be connected to the PICA computer is available here, as well
as a desk, cabinets and several tables.
There is a small
of tools and test equipment (multimeter, oscilloscope, signal
available for visitor use.
Observers bringing their
not rely solely on this, however, but should bring with them any spare
or test equipment they
- Clean Room
CFHT maintains a clean
room for detector repair/maintenence at the summit.
- LAMA Room (4th
The YAg LAser MAchine
is located on the fourth floor adjacent to the Auxiliary Observing
It is connected to the local area
computing network. Observers use this
facility to cut masks for multi-object spectrography (MOS/OSIS).
- CCD Lab (3rd Floor)
The CCD Lab is used
for storage and preparation of the MegaCam.
- Infrared and
Facilities (2nd and 3rd Floors)(Waimea Headquarters)
Lab space is available
on the 2nd and 3rd floors.
A modest optics lab
and clean room are availible at the Waimea Headquarters facility.
to these labs should be
prearranged with your Support Astronomer.
- Mechanical Shop
A small mechanical
contains a bandsaw, cut-off saw, vise, shear, drill press, grinder,
milling machine, welding
equipment, and an
assortment of hand tools.
equipment is not intended for instrument fabrication. It is for
repairs only and is not
available to Observers.
- Electronics Shops
Labs (2nd and 3rd Floors)
A modestly equipped
lab is located in the building and is used for servicing the telescope
and CFHT instrumentation.
This laboratory is for staff use and is not
to Observers. Observers should use the work station located in the
A CCD lab is
in Room 319. It is used by the staff for preparation of the CCD runs.
- Living Facilities
A heated lounge on the
fourth floor ("Café du Mont Blanc") is provided with comfortable
furniture, and a kitchenette. This facility
is for use by observers,
and guests for short rest periods during the day or night.
leave the kitchen in good order, especially during weekends when no
staff is on duty.
On the third floor
one small bedroom and a washroom for use by personnel during day or
These bedrooms are
humidified but not
pressurized. Individuals should
that sleeping at 4200 m is very difficult, and not always
unless one is fully acclimatized.
- Weather Station
A weather station is
on a tower adjacent to the dome. Readouts of the weather station
are found directly
above the TV monitors at
the telescope control
A chart recorder view is also availible, on the Telescope Status
of the Telescope Control
System (TCS). The instrument levels are shown
in colored traces. Several FITS keywords of
data are added to the FITS header of each image file.
- Compressed Air
Seven-bar filtered and
dried compressed air is available for use by Observers at the following
- instrument labs
- optics labs
(including the LAMA
section needs updating and inclusion of the MegaPrime cooling system)
Because of the expense
of trucked water, a recirculating cooling system has been installed for
all cooling purposes by
The cooling points are
with a valved supply line and a drain and are installed in the
Coolant characteristics are
- maximum flow: 40
- maximum pressure:
Dry nitrogen outlets
available at telescope foci. Dry nitrogen is also available in cylinder
form, complete with gauges, on a
- Electrical Power
Electrical power at
summit is provided by the Island-wide HELCO (Hawaii Electric Light
grid which supply 480 volts,
3 phase, 60 Hz. Every room within the
is equipped with 110 volts 15 amp, 1 phase circuits. In addition, there
special purpose 40 amp and 15 amp, 208 volt, 3 phase plugs
on the observation floor, coudé rooms, coudé observation
rooms and LAMA room. The regulation is generally plus or minus 5% in
and plus or minus 1 Hz.
To take care of fluctuating power, a Uninterrupted Power Supply system
has been installed for certain
All plugs in the
conform to American standards. French standard plug adapters and
volts transformers up to 50 kvA
of portable electric supply boxes, is available for the following
a) 220 volt, 1
60 Hz with French plugs.
b) 220 volt, 50 Hz,
1 phase regulated power
or minus 2 percent, with French plugs.
The CFHT dome has a
purpose intercom system. 14 stations and 25 speakers are located
the dome, allowing
for easy paging.
To make a general
press "Page" at any telephone station. After the tone burst, speak into
the transceiver, then
Apart from the
is also an independent communication system called Clear-Com. This
of a network of
8 remote stations controlled from the Control Room
and is very useful for talking to the O.A. on a permanent basis, using
the gooseneck microphone at the astronomers' console at coudé
from the prime focus cage or from the auxiliary observing
are: the upper coudé room, the slit room, the Cassegrain
the prime focus cage, etc. If the
voice level is too low, slightly turn
up the Headset/Speaker volume knob on the remote station KBIII (the
steel base at
the right side of the observer's console front panel). Be
careful; with the live microphone it is easy to get loud feedback by
the speaker up too much.
available, which allow permanent communication from anywhere in the
these dome audio-systems can be received by contacting staff
telescope operators and other
technical staff members
- Loaned Equipment
On special occasions,
certain instruments or apparatus may be loaned to Observers who have
difficulty with their own
equipment. Observers should not, however,
on the availability of any apparatus on loan unless prior explicit
been made in writing with
the Corporation. This applies, for
to such items as vacuum pumps, oscilloscopes, amplifiers,
Observers may use the
telephone at the summit. It is very reliable, but occasionally may be
of operation for a few days at a
time during severe
calls should be made collect, by credit card, or billed to a home phone
In cases when it is
impossible to do this, Observers may still
make calls which will, in turn, be billed to them.
There also is
a FAX machine (No. (808) 935-4511).
A small photocopier is
available in the staff office (4th Floor). It may be used for a limited
amount of copying.
- Safety Equipment
Hard hats are required
in the dome and hatch areas. They are located on the 4th and 5th floor.
In case of minor
aid supplies can be found in the first aid room on the ground floor and
at various other locations
throughout the building.
For emergency escape
in case of fire or trapping) escape
have been installed on the 4th and
exit doors, as well as in
the crane cab inside the dome.
The CFHT Base Facility
is located in Waimea (Postal Address Reference: KAMUELA 96743) on the
of Hawaii. The building
is situated on the north side of Highway 190
300 m west of the intersection of Highways 190 and 19.
The town of Waimea
region have a population of about 15,000. The principal economic
ranching, diversified agriculture, and service industries.
Parker ranch is by far the largest of the cattle ranches
or 100,000 hectares). In Waimea, there is a post office, medical
several banks, several shopping centers,
and a theater.
work place for most of the Corporation's staff members. In addition to
offices, there is a data
reduction facility, a library, optics and
labs, a technical design (CAD) lab, machine shop, and vehicle
strongly encouraged to spend a day or so in Waimea before or after
run. They are most welcome to
present some of their current work in an
~45 minute long, relaxed seminar. An overhead viewer and LCD projector
The Data Reduction
is available to meet the needs of the visiting astronomer in the areas
of data backup, data retrieval,
and preprocessing. The primary purpose
of the facility is to allow the visiting astronomer to preprocess data
from CFHT detectors
to a degree that the astronomer is able to start
analysis and/or to remove a record of their observations to their home
of taking their raw telescope data offsite or having them concatenated
to reduce the amount of
media. Observers can also have copies made of
raw data for co-investigators etc. Observers should plan on spending
a day in Waimea at the end of their run if they require data
record of all observations taken with the data acquisition system. This
record is made in
real time and recorded on optical disk. When full the
optical disks are shipped to the Canadian Astronomical Data Centre
in Victoria, BC, Canada for eventual inclusion in an Archive
of CFHT data, through which non-proprietary data is
to interested researchers. In the event of inadvertent loss of any FITS
files, the Principal Investigator can
arrange to have images recovered
from the Canadian Astronomy Data Centre. Due to the technologies
it is not
always possible to recover FITS files immediately.
The library has modest
holdings of astronomical and engineering books, scientific and
periodicals, and catalogues. In
addition, the library houses the
Sky survey, current instrumentation manuals, reports, and technical
other leading observatories.
Consult the Librarian
or the CFHT
Library Home Page for details.
helium and dry ice can be provided to observers.
LN2 is purchased in
160-liter dewars (owned by CFHT). It is produced in Honolulu and
by barge to Hilo,
from where it is transported to the observatory by
staff. We usually decant the LN2 into self-pressurizing 25-liter dewars
ease of use. No charge is made for the LN2 required for CFHT
or for similar small amounts used by visitor instruments.
LHe is purchased in
100-liter or 60-liter dewars. Our experience is that the dewars are on
average 60% full when they reach
the summit. Normal boiloff in storage
is 1-2 liters/day. Although LHe is now produced in Honolulu, it is
occasionally necessary for
us to obtain our supply from California. LHe
is considered hazardous cargo by many freight companies and usually
travel by surface--hence the need for six weeks' notice.
Dry ice must be
Honolulu, in 50 pound (23 kg) increments.
- Magnetic Tapes
Data storage media is available
for Guest Observers using CFHT instruments.
Gear and Survival Kit
nighttime temperatures can be as low as -6 C. Furthermore it is our
to keep ambient temperature
below +15 C in most rooms in the telescope
In order to guarantee
adequate cold-weather gear, Observers should provide it for themselves,
trousers, and hooded parkas can be rented at Hale
Pohaku. In all cases, leather or thermal boots should be brought by
even during summer. Low oxygen concentration and the resultant lowering
of metabolism at 4200 meters make the temperature
seem colder than it
be at a lower altitude. Comfort items such as, lip balm and lotion for
dry skin, analgesic for headaches
(aspirin or acetaminophen) are also recommended.
Visitor's should bring
their own flashlights and batteries.