Milestone-Proposal:First Radio Astronomical Observations Using VLBI, 1967

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Docket #:2009-11

This is a draft proposal, that has not yet been submitted. To submit this proposal, click on the edit button in toolbar above, indicated by an icon displaying a pencil on paper. At the bottom of the form, check the box that says "Submit this proposal to the IEEE History Committee for review. Only check this when the proposal is finished" and save the page.

To the proposer’s knowledge, is this achievement subject to litigation?

Is the achievement you are proposing more than 25 years old?

Is the achievement you are proposing within IEEE’s designated fields as defined by IEEE Bylaw I-104.11, namely: Engineering, Computer Sciences and Information Technology, Physical Sciences, Biological and Medical Sciences, Mathematics, Technical Communications, Education, Management, and Law and Policy.

Did the achievement provide a meaningful benefit for humanity?

Was it of at least regional importance?

Has an IEEE Organizational Unit agreed to pay for the milestone plaque(s)?

Has an IEEE Organizational Unit agreed to arrange the dedication ceremony?

Has the IEEE Section in which the milestone is located agreed to take responsibility for the plaque after it is dedicated?

Has the owner of the site agreed to have it designated as an IEEE Milestone? Yes

Year or range of years in which the achievement occurred:


Title of the proposed milestone:

First Radio Astronomical Observations Using VLBI, 1967

Plaque citation summarizing the achievement and its significance:

200-250 word abstract describing the significance of the technical achievement being proposed, the person(s) involved, historical context, humanitarian and social impact, as well as any possible controversies the advocate might need to review.

IEEE technical societies and technical councils within whose fields of interest the Milestone proposal resides.

In what IEEE section(s) does it reside?


IEEE Organizational Unit(s) which have agreed to sponsor the Milestone:

IEEE Organizational Unit(s) paying for milestone plaque(s):

Unit: Vancouver Section
Senior Officer Name: Dave Michelson

IEEE Organizational Unit(s) arranging the dedication ceremony:

Unit: Vancouver Section
Senior Officer Name: Dave Michelson

Unit: Vancouver Section
Senior Officer Name: Tom Landecker

IEEE section(s) monitoring the plaque(s):

IEEE Section: Vancouver Section
IEEE Section Chair name: Dave Michelson

Milestone proposer(s):

Proposer name: Dave Michelson
Proposer email: Proposer's email masked to public

Please note: your email address and contact information will be masked on the website for privacy reasons. Only IEEE History Center Staff will be able to view the email address.

Street address(es) and GPS coordinates in decimal form of the intended milestone plaque site(s):

Dominion Radio Astrophysical Observatory, 25 km from Penticton, British Columbia, Canada.

Describe briefly the intended site(s) of the milestone plaque(s). The intended site(s) must have a direct connection with the achievement (e.g. where developed, invented, tested, demonstrated, installed, or operated, etc.). A museum where a device or example of the technology is displayed, or the university where the inventor studied, are not, in themselves, sufficient connection for a milestone plaque.

Please give the address(es) of the plaque site(s) (GPS coordinates if you have them). Also please give the details of the mounting, i.e. on the outside of the building, in the ground floor entrance hall, on a plinth on the grounds, etc. If visitors to the plaque site will need to go through security, or make an appointment, please give the contact information visitors will need. The Dominion Radio Astrophysical Observatory (DRAO) is a National Facility for astronomy operated by the National Research Council Canada. It is operated to support the research of the Canadian astronomy community, mostly consisting of researchers in universities. The plaque will be installed on the base of the DRAO 26-m radiotelescope that was used as the western site of the first successful VLBI radio astronomical observations in April 1967 observations. This location will be readily accessible to the several thousand members of the general public that visit the Observatory site each year. For related background, see

Are the original buildings extant?


Details of the plaque mounting:

How is the site protected/secured, and in what ways is it accessible to the public?

The site is accessible to the public seven days a week from Easter to Thanksgiving and five days a week through the winter. When staff are not present, the DRAO site is secured by electronically operated access gates and a security system. Observatory scientists typically give tours to 1000 school students throughout the year. A professional guide typically gives weekend tours to 5000 visitors per year. Casual self-guided visitors to the site typically number 5000 each year. The Observatory holds an Open House every September that typically attracts over 1000 visitors each year.

Who is the present owner of the site(s)?

National Research Council Canada (NRC)

What is the historical significance of the work (its technological, scientific, or social importance)? If personal names are included in citation, include justification here. (see section 6 of Milestone Guidelines)

From its Canadian beginnings, VLBI has become an important technique for both radio astronomy and geodesy. It has been the central theme of over 3,500 papers in the scientific literature over the ten-year period 1999 to 2008, and the flow continues unabated. VLBI provides better angular resolution than any optical telescope and can reveal details within some of the most distant objects detectable. Astronomers use VLBI to provide crucial tests of General Relativity, to demonstrate definitively the existence of black holes in galaxy cores, to test the fundamentals of high energy physics, and to look back to the early Universe. VLBI techniques also permit the position of objects on Earth and in the solar system to be measured with millimetre accuracy with respect to the ultimate reference frame, distant quasars. Such techniques are now routinely used: (1) to precisely track spacecraft on voyages to the planets and (2) to provide the basis for precise geodetic surveying including important studies of the movement of crustal plates, earthquake prediction and Earth rotation. See, for example, J. L. Yen, P. Leone, G. A. Watson, J. K. Zao, J. Popelar, W. T. Petrachenko, G. Feil, W. H. Cannon, P. Mathieu, P. Newby, H. Tan, R. D. Wietfeldt, and J. A. Galt, '

What obstacles (technical, political, geographic) needed to be overcome?

The principal technical challenge was to establish two independent receiver systems with individual clocks and recording devices that were sufficiently stable to maintain coherence over periods of many minutes and sufficiently sensitive to detect the very weak radio astronomical signals. Great ingenuity was applied to operating within a limited budget and adapting existing equipment to the task. For example, the first VLBI observations were collected using surplus video recorders that had been purchased from the Canadian Broadcasting Corporation.

What features set this work apart from similar achievements?

Short-baseline interferometry had been used in radio astronomy for high-resolution imaging since the 1940’s. Cables or (sometimes) radio links were used to connect two or more radio antennas to signal processing equipment. The distance or baseline between pairs of antennas in such interferometers was initially small but gradually became larger over time. It soon became clear that important astrophysical questions could be answered only by building interferometers with baselines greater than any cable or radio link could span. The proposed IEEE Milestone will recognize the first successful radioastronomical observation made using such techniques.

Supporting texts and citations to establish the dates, location, and importance of the achievement: Minimum of five (5), but as many as needed to support the milestone, such as patents, contemporary newspaper articles, journal articles, or chapters in scholarly books. 'Scholarly' is defined as peer-reviewed, with references, and published. You must supply the texts or excerpts themselves, not just the references. At least one of the references must be from a scholarly book or journal article. All supporting materials must be in English, or accompanied by an English translation.

Supporting materials (supported formats: GIF, JPEG, PNG, PDF, DOC): All supporting materials must be in English, or if not in English, accompanied by an English translation. You must supply the texts or excerpts themselves, not just the references. For documents that are copyright-encumbered, or which you do not have rights to post, email the documents themselves to Please see the Milestone Program Guidelines for more information.

Please email a jpeg or PDF a letter in English, or with English translation, from the site owner(s) giving permission to place IEEE milestone plaque on the property, and a letter (or forwarded email) from the appropriate Section Chair supporting the Milestone application to with the subject line "Attention: Milestone Administrator." Note that there are multiple texts of the letter depending on whether an IEEE organizational unit other than the section will be paying for the plaque(s).

Please recommend reviewers by emailing their names and email addresses to Please include the docket number and brief title of your proposal in the subject line of all emails.