Guidelines for AAT Visitor Instruments

These guidelines are for observers who wish to use their own instrumentation on the Anglo-Australian Telescope.

Full and clear communication between observers and the AAO is essential at all stages, especially for instruments which have not been used previously on the AAT. If uncertain about any issue, ask early!


The OBSERVER'S GUIDE: Obtain a copy of the ``AAO Observer's Guide'' - it contains a wealth of information. Download a copy of Yellow Book, which is (slightly) more up to date.

WORLD-WIDE WEB: Information on the Observatory may be found through our homepage.

LOCATION: The Australian Astronomical Observatory occupies two sites. Most administrative and scientific staff are based in the Sydney suburb of North Ryde; most technical staff are stationed at the telescope on Siding Spring mountain, Coonabarabran, 500 km NW of Sydney. In addition to the 3.9 m Anglo-Australian Telescope (AAT), it also operates the 1.2 m UK Schmidt Telescope (UKST).

OBSERVING TIME: Observing time on the AAT is awarded by a single joint Australian Time Assignment Committee. Applications are due March 15 for the following August-January semester, and September 15 for the following February-July semester. More details can be found from the WWW application pages. Special arrangements exist for the UKST, for which observing time is available only on a user-pays basis. If your plans pertain to the UKST, contact the Astronomer-in-Charge, Fred Watson.

POWER SUPPLY: Australian mains supply is 240 volt, 50 Hz, single phase. Three phase is also available at the telescope; check availability if you need it. Single phase 110 volt, 50 Hz is also available with limited distribution, but 110 volt 60 Hz is not; again, check availability if you need 110 volts.
Contact: Doug Gray - Operations Manager, AAT.

COMPUTING FACILITIES: North Ryde and Coonabarabran have similar facilities. General user machines are Linux PCs; these share disks, and most are on the Internet. Interaction between AAT facility instruments (e.g. UCLES, IRIS2) and visitor instruments is possible via an RS232 serial-line interface. IRAF, Starlink, and IDL are the standard data reduction packages available at the telescope.
Coonabarabran contact: Chris Ramage  - IT Manager.

TRAVEL: Visitors from most countries (including the UK and USA) must obtain a visa to enter Australia, prior to travelling. Apply to your nearest Australian Consulate in plenty of time; a list of consulates, embassies, and High Commissions is available from the DFAT website.

Flights to and from Australia are often booked well in advance, especially around December-January, so book early. There are several options for travel between Sydney and the AAT:

  • Fly Sydney-Dubbo, then hire a car or taxi to get to the telescope.
  • Rental car (6-8 hour drive on secondary roads). Australians drive on the left hand side of the road; so should you!
  • Train to Lithgow (2 hour), bus to Coonabarabran (6 hours), taxi to telescope.

Freighting and customs clearance of equipment is discussed below.


EARLY PLANNING: The very first step is to contact the Director of the AAO  and request permission in principle to bring a visitor instrument. Describe the instrumentation, estimate the level of support required from AAO personnel, and describe the scientific goals. This should be done before applying for observing time; AATAC will reject visitor instrument proposals which do not already have the approval of the Director.

The full costs of shipping and interfacing the instrument to the telescope are the responsibility of the applicant. The AAO will provide logistical and technical assistance, but does not provide financial support to visitor instruments.

The Director will nominate a member of the AAO scientific or technical staff to act as intermediary for your visit. He/she will help to ensure that all important issues are considered in good time, and will be able to answer questions on the AAO and its facilities or will put you in contact with someone who can. Keep this person fully informed of all developments, good or bad, and be sure to discuss the following issues early.


  • What consumables do you require? Have you arranged for their timely delivery, or arranged to use AAO supplies?
  • Do you require a flow of coolant? If so, give details of the type of liquid, connector, rate and temperature required.
  • Does your instrument require any pressurised gases? If so, supply details of the type, connector, volume, delivery rate and pressure required.
  • Do you require any cryogenic equipment or facilities?
  • Do you require any high vacuum evacuation of your equipment? What connection type, pumping rate, and ultimate vacuum are required?
  • Do you expect to use AAO filters? Have you verified that we have the required type and size?


  • Ensure that your equipment fits to the AAO mounting flanges. Is any special machining required, and if so, who will do it? What is the back focal distance? Is the focal plane where you expect it to be? See the WWW Observers' Guide for details.
  • If you intend to use an AAO detector, do you have sufficient back focal distance to enable the use of the standard cryostats? Have you checked that you have sufficient clearance for the dewar electronics?
  • Will you be using the AAO's acquisition and guiding system? If so, is your instrument compatible with it? If you need slit-viewing capabilities, is your slit orientated correctly for our TV system? Is your instrument at the nominal Cass. focus? If not, is it still within the focus range of both the TV and autoguider?
  • Does your instrument fit within the space available? Include allowance for CCD controllers in the Cassegrain cage, and for people in the prime focus cage.
  • If you have rack-mounted equipment, does this fit a standard 19 inch rack or are modifications required?
  • Are there any protruding or motorised items (e.g. filter wheels, acquisition cameras, shutters) which require additional clearance?
  • Do you expect to use any AAO filters? If so, does it require the fabrication of any hardware to mount the filters?
  • Will you need access to your equipment during the night? If so, will someone have to ride in the Cassegrain or prime focus cages? Do you have enough observers?


  • What are the power supply requirements?
  • What cabling do you require between your instrument and the control room or other equipment? Have you packed enough lengths and spares?
  • Will you be connecting your equipment to ANY AAO electronic equipment? If so, discuss this in detail with Bob Dean. Is the equipment compatible? Do you have the right connectors and spares?
  • Does your equipment need to exchange information with the telescope control system? Do you need to read telescope position and field orientation information into your software or data headers, or do you need to send electronic instructions to the telescope control system?
  • Will you be relying on any AAO software? If no, do you really mean no?
  • Do you expect AAO electronics or software to control your instrument shutter or filter wheels etc?


  • If you need to network your equipment, discuss your requirements and obtain IP numbers from Chris Ramage.


Your equipment is your responsibility. AAO support, where offered, is on an ``all care, no responsibility'' basis. Clarify in advance what support you will need, or may need if things go wrong. If you do approach us for technical support, the following items will greatly increase the chance of success:

DOCUMENTATION: Carry documentation for ALL of your equipment where possible. This should include wiring diagrams, circuit diagrams, operating system and computer user guides, data sheets for unusual components, and mechanical and optical drawings.

COMPUTING: Make a complete backup of your system and application software before departure. Bring all media and documentation to reinstall your operating system and application software from scratch. (Heed the voice of experience!) It is strongly recommended that you do a trial rebuild before departure. If you do not feel confident doing this, consider bringing additional support or at least pre-arrange a remote support person for the duration of the run. Consider bringing a spare disk drive preloaded; borrow one if necessary.

SPARES: Coonabarabran is remote, so access to specialist items can be difficult. Bring spares to cope with faults. We recommend that you bring spare power supplies, motors, encoders, couplings and specialist electronic components. Vulnerable components include line driver/receivers, programmable logic gates (bring the data, blank devices and hardware to regenerate them), disk and tape drives.

ISOLATION: All of the detectors used on the telescope are electrically isolated from the telescope to avoid electrical interference. Is your detector electrically isolated from its mounting flange?

COMMUNICATION AND EARLY ARRIVAL: The most important factors in a successful visiting instrument run are time and communication. Ensure that you discuss all requirements well in advance, and arrive in plenty of time to unpack and set up the instrument, test, repair if necessary, and arrange for any final work required for integration into the telescope systems.


Your equipment should be in good working order before you freight it.

Shipping may induce faults in previously reliable equipment. A high standard of packaging is required. The use of original packing material within professional standard metal trunks is recommended. If locked, provision must be available to open the goods for customs inspection. Unnecessary damage can be prevented by due care; consider the use of professional shipping agents if you do not feel confident. Label any items which need especially careful handling by customs inspection officers.

Customs clearance is required for visitor instruments, which involves time and paperwork. See the Shipping Guide for detailed information.
North Ryde contact:  AAO Administration.

Freight the equipment early, allowing extra time for customs clearance and forwarding from Sydney to Coonabarabran. You and your equipment should arrive well before the run to give you time to check that it works (i) after freighting, handling, and inspection by customs, and (ii) in the AAT environment. Allow time for unexpected modifications to be made. Determine in advance who will unpack it and set it up when it arrives.
Coonabarabran contact: Doug Gray  - Operations Manager, AAT.

Most visitor equipment must leave the country within a finite period to avoid being charged import duties. Allow time at the end of your run to re-pack the equipment. Note that only minor instrument changes are undertaken at weekends and on public holidays, so check in advance when your equipment will be taken off the telescope.

REMEMBER: If you have any questions or are not absolutely certain of anything, ASK EARLY!