Milestone-Proposal:First Digitally Processed Image from a Spaceborne Synthetic Aperture Radar

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Docket #:2013-05

This Proposal has been approved, and is now a Milestone

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

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

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. Yes

Did the achievement provide a meaningful benefit for humanity? Yes

Was it of at least regional importance? Yes

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

Has the IEEE Section(s) in which the plaque(s) will be located agreed to arrange the dedication ceremony? Yes

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

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 Digitally Processed Image from a Spaceborne Synthetic Aperture Radar, 1978

Plaque citation summarizing the achievement and its significance:

In November 1978, a team from MacDonald, Dettwiler and Associates Ltd. (MDA) became the first to use a digital processor to reconstruct an image from Seasat-A, the first civilian spaceborne synthetic aperture radar (SAR). MDA engineers subsequently developed three of the four most important SAR digital processing algorithms that replaced the optical processing methods used previously.

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: IEEE Vancouver Section
Senior Officer Name: Alon Newton

IEEE Organizational Unit(s) arranging the dedication ceremony:

Unit: IEEE Vancouver Section
Senior Officer Name: Alon Newton

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

IEEE Section: IEEE Vancouver Section
IEEE Section Chair name: Alon Newton

Milestone proposer(s):

Proposer name: David G 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):

13800 Commerce Parkway Richmond, BC V6V 2J3

latitude, longitude: 49.1753696, -123.0704193

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. We propose to mount the plaque in the lobby of MDA's headquarters at 13800 Commerce Parkway Richmond, BC V6V 2J3. Although this is not the location where the achievement occurred, it is where all follow on work at MDA in the area of SAR processing and applications has been pursued since the early 1990s.

Are the original buildings extant?

No, MDA moved to a new building in the early 1990s.

Details of the plaque mounting:

We propose to mount the plaque in the lobby of MDA's headquarters.

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

The plaque will be located in the lobby, which is outside the secure area of the building. All visitors to MDA will be able to view the plaque alongside other historical exhibits including a scale model of the Prince Albert Earth Station, the Canadarm, etc.

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

MacDonald Dettwiler and Associates

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 the time that Carl A. Wiley of Goodyear Aircraft Co. introduced the synthetic aperture radar (SAR) concept in 1951, optical correlators based upon various combinations of exotic lenses and optical film had been used to reconstruct synthetic aperture radar imagery. While reconstruction could be accomplished in reasonable time using such techniques, the results suffered from various artifacts associated with slight physical imperfections in the optical system and the limited dynamic range of the optical system. While the possibility of using digital technology to process SAR data had been recognized early on, the processing requirements greatly exceeded the capabilities of the general purpose computers available to researchers in the 1950's and 1960's. The state of the art as of 1970 is summarized in [1].

At the same time, it had been recognized that a synthetic aperture radar carried by an orbiting satellite would offer many important advantages over airborne SARs. First, orbiting Earth observation satellites can achieve worldwide coverage with an ease that airborne platforms cannot match. Second, orbiting SARs are not buffeted by the atmospheric turbulence that shakes airborne SARs; the path that they take through airless space is ultra smooth and highly predictable. These advantages are only partially offset by the reduced resolution and lower signal-to-noise ratio achievable with orbital SAR imagery due to their much greater height above the Earth's surface.

Tremendous advances in minicomputer technology during the early 1970's renewed interest in the possibility of placing a synthetic aperture radar in low earth orbit and using general purpose computers to produce high quality imagery from the downlinked data. Seasat-A. the world's first orbital SAR, was launched by NASA in 1978. Although it failed within 90 days of achieving orbit due to a power system defect, Seasat-A demonstrated the enormous potential of orbital SARs and ushered in three decades of innovation that saw orbital SARs of ever increasing power and capability launched by NASA, the European Space Agency and the Canadian Space Agency.

Several teams competed to be the first to reconstruct a scene by digitally processing Seasat-A SAR data. However, the general purpose minicomputers available to engineers in the late 1970's were only barely capable of supplying the enormous processing power required. It was widely expected that a large, well-funded team from NASA's Jet Propulsion Laboratory would prevail. Instead, a small, upstart team from Canada's MacDonald Dettwiler and Associates that had begun their task two years earlier won the race in November 1978 [2].

So significant was the accomplishment that this first image was featured in the 26 February 1979 issue of Aviation Week and Space Technology [3]. Details were reported at several conferences early in 1979 [4],[5]. JPL was behind and as recently as 1980 was still reporting results that had been processed using the less capable optical techniques [6].

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

MDA's accomplishment underscored a lesson that would be repeated many times as the digital revolution progressed. Other teams had access to the same SEASAT data and similar general purpose digital computers. However, it was the MDA team's careful mastery of algorithm design and software engineering that allowed them to win the race to become the first to produce a digitally processed data from Seasat-A data.

MDA exploited their early success to become one of the most influential and prolific developers of digital SAR processing algorithms and digital SAR processors in the world. Teams at MDA developed three of the four common SAR processing algorithms in use today: Range/Doppler, Chirp Scaling, and SPECAN. MDA also developed the digital SAR processors used by such notable NASA, ESA and CSA programs as SIR-B, SIR-C, ERS-1, J-ERS-1. RADARSAT-1, ENVISAT and, most recently, RADARSAT-2 [7].

What features set this work apart from similar achievements?

The events of November 1978 marked a turning point in the history of synthetic aperture radar. Demonstration that data from spaceborne SARs could be digitally processed using general purpose digital computers helped to dramatically reduce the cost of SAR imagery and make it much more widely available for civilian applications. Until 1978, military applications of SAR were predominant. Since 1978, civilian applications of SAR have assumed steadily increasing importance.

The reputation that MDA earned from this accomplishment fuelled its rapid growth into the world's largest supplier of SAR processors and Canada's largest space technology company.

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.

[1] R. O. Harger, "Synthetic Aperture Radar Systems: Theory and Design." Academic Press, New York, 1970.

[2] Herbert J. Kramer, "Observation of the Earth and Its Environment: Survey of Missions and Sensors," 4th ed., Springer, 2002, p. 32.

[3] "Seasat Imagery Shows St. Lawrence," Aviation Week and Space Technology, 26 Feb. 1979. [Clipping Available Online.]

[4] I. Cumming and J. Bennett, "Digital processing of Seasat SAR data," in Proc. IEEE ICASSP '79, Apr 1979, pp. 710-718. [Available Online.]

[5] John R. Bennett and Ian G. Cumming, "A Digital Processor for the Production of Seasat Synthetic Aperture Radar Imagery," LARS Symposia, Purdue Univ., 1979, Paper 316. [Available Online.]

[6] R. L. Jordan, "The Seasat-A synthetic aperture radar system," IEEE Journal of Oceanic Engineering, vol. 5, no. 2, pp. 154-164, Apr. 1980. [Available Online.]

[7] I. G. Cumming and F. H. Wong, “Digital Processing of Synthetic Aperture Radar Data”, Artech House, 2005. [Summary Available Online.]

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.