Memorandum of an Agreement to Cooperate in a Technology Study Program Leading to a Future Very Large Radio Telescope

The undersigned, representing their respective institutes, considering that:

astronomy is an observational science, best advanced by continuing improvements in technology and in observational technique;
the diverse physical phenomena observed in the universe can best be understood by making measurements in all parts of the electromagnetic spectrum, including centimeter to meter wavelengths; and
in future astrophysical measurements at radio wavelengths will be of primary importance for the understanding of:
1. the formation of large scale structure in the early universe;
2. the formation of galaxies in the early universe and aspects of their evolution at subsequent epochs;
3. the frequency of other technological civilizations in the universe;
4. extreme states of matter and exotic phenomena not reproducible in the laboratory, including black holes and neutron stars, naturally occurring mega-masers and high energy and transient phenomena in plasma physics; and
5. aspects of stellar physics and the evolution of stars, including the role of stellar magnetic fields;

having jointly concluded that:

future progress in these fields will require an increase in sensitivity of at least an order of magnitude over and above what current radio telescopes can provide, and broad wavelength coverage;
this increase will be acquired mostly by increasing the collecting area of future telescopes and not solely by improvements in receiver technology or in other parts of the detection process; and
realization of the benefits of this improved sensitivity will require significantly improved techniques for rejecting radio frequency interference from the environment, which in future will result principally from the rapidly expanding use of the radio spectrum for commercial services including satellites;

and having noted that:

the study of galaxies in the early universe leads naturally to a requirement for a total effective collecting area approaching a square kilometer;
the development of future large scale facilities in astronomy is beyond the capabilities of most individual countries; and
a proper distribution of effort is desirable for the world wide development of science;

do hereby agree to cooperate on a study and development program to identify and detail the technological and political approaches available to bring about the construction of a future large radio telescope at centimeter to meter wavelengths.

Nature of the program

Specific goals

The principal goal of this program is to select a conceptual design for a new, very large telescope, and to do so by the year 2000. In addition, the participants will work to define an organizational framework within which a telescope project can be carried out.

Cooperation

Cooperation in this context will consist of regular communication of the studies to be carried out at our respective institutes. The intention is that our world-wide efforts, when well coordinated, will lead to a generally accepted and practically realizable concept for the telescope.

The Netherlands Foundation for Research in Astronomy agrees to take the lead in ensuring that communication does in fact occur and that an end report is prepared and distributed to all interested parties.

Cooperation and coordination will proceed on the basis of "best effort" by each party and without commitment to exchange funds.

Unless otherwise required by contract or agreement with third parties, it is the intention that all documents and results from our studies will be made freely available to all interested parties.

Cooperation with parties not initially named here will be encouraged. Additional parties may join the Agreement formally with the consent of the other participants.

Study program

The study program will have the following main elements:

The institutes will jointly compile an inventory of the scientific case. The NFRA agrees to coordinate production of a first version of this inventory during 1996. A final version will accompany the study program's end report by the year 2000, which will clearly identify the scientific questions that most influence the technical definition and the total cost of the telescope.
Technical studies will be undertaken of antenna design and of detection strategies, of techniques for suppression of interferring signals, and of techniques for connecting components in massively parallel architectures and for real-time signal processing. These studies will be divided among our institutes initially as detailed below.
Detailed siting criteria will be formulated jointly and potential locations will be identified and summarized in the end report.
Preliminary cost estimates for construction and operations will be developed and summarized in the end report.

Technical studies

Additional to the joint activities noted, each institute will undertake to study specific technical solutions as follows:

The Australia Telescope National Facility (Sydney, Australia) will coordinate the investigations of several Australian groups relating to broad band phased array antennas and their coupling to low noise detection electronics in various possible implementations.
The Herzberg Institute of Astrophysics (Victoria, Canada) will investigate designs which divide the total collecting area into several tens of element telescopes, each having a large focal ratio and a receiver unit at the prime focus mounted on an airborne platform.
The Beijing Astronomical Observatory (Beijing, China) will investigate designs which divide the total collecting area up into several tens of element telescopes, each having a short focal ratio and a mechanically suspended receiver unit at the prime focus.
The National Centre for Radio Astrophysics (Pune, India) will investigate designs which divide the total collecting area up into many small, fully steerable, parabolic dish telescopes.
The Netherlands Foundation for Research in Astronomy (Dwingeloo, Netherlands) will investigate the application of phased array technologies to the telescope, including possibilities for fully electronically steered, multiple beams and adaptive rejection of unwanted signals.
The SETI Institute (Mountain View, USA) will consider concepts in which the total collecting area is divided up into of order a thousand element telescopes. In addition, optimization for wide bandwidth and high frequency resolution will be studied, as well as novel techniques for suppression of external interference.
The National Astronomy and Ionospheric Center (Arecibo, USA) will consider the constraints imposed on the technical specifications by radar studies of solar system bodies. In addition, the extensive experience at Arecibo with a large, spherical dish telescope having short focal length will be made available.
The Ohio State University Radio Observatory (Columbus, USA) will investigate wide-band, timed- array designs which form beams covering the entire sky simultaneously, and the novel interference rejection techniques which this approach makes possible.

It is expected that the focus of these technical areas will evolve in the course of the studies.

Additional groups, specifically in France, Israel and the United Kingdom, have expressed serious interest in joining in the studies at a later date, when they identify how best they might contribute.

Signed,

Dr. Ron D. Ekers, Director - Australia National Telescope Facility, CSIRO

Dr. Don C. Morton, Director General - Herzberg Institute of Astrophysics, NRC

Prof. Nan Rendong, Deputy Director - Beijing Astronomical Observatory, CAS

Dr. Vijay K. Kapahi, Director - National Centre for Radio Astrophysics, TIFR

Prof. Harvey R. Butcher, Director - Netherlands Foundation for Research in Astronomy, NWO

Prof. Frank Drake, President - SETI Institute

Prof. Paul Goldsmith, Director - National Astronomy and Ionosphere Center, NSF

Dr. John Kraus, Director -Ohio State Univ. Radio Observatory, OSU