Remote sensing then and now

Convair

Keith Raney

Leon Bronstein

In 1969 when the Planning Office was set up, there were only four Canadian companies interested in remote sensing, - MDA in Vancouver and CDC of Ottawa, involved in satellite ground readout stations, Intera of Calgary, in airborne remote sensing and RCA Montreal in sensor development. Under the 'Make-or-Buy' policy CCRS contracted out as much work as was possible. Later, other companies came on stream in remote sensing, but the original ones got a head start.

Ray Lowry

In the original plan, applications did not have a high priority because, as mentioned, it was planned that this work would be taken on by the Provincial Remote Sensing Centres, supported financially by the Federal Government. Because of the general breakdown of federal/provincial relations, this plan did not happen, and there was a major delay of from 5 to 10 years before the provinces managed to fund their own remote sensing offices. It was therefore recommended by nearly all the applications working groups that CCRS re-enforce the more practical side of applications development work in-house, which up to that time had been staffed by only three scientists, Bob Ryerson, Tom Alföldi and Jean Thie, who left the Manitoba Centre to head up the CCRS Applications Development Section. David Goodenough with a staff of three mathematically-trained staff had been working on the theoretical methodology side of digital image processing. Both these sections were managed by Joe Mac Dowell who left about this time to become Science Counsellor for the Canadian Embassy in Washington.

Paul Hession

Some universities became involved in remote sensing from the beginning through the involvement of some of their professors on the various CACRS Working Groups. However some of them had difficulty as did the governments, because of the interdisciplinary aspect of remote sensing. In the beginning, they could not afford the large budgets to fund the expensive computers and digital image analysis systems. Physics and electrical engineering departments were interested in the sensor development. Applied mathematics, computer science and electrical engineering departments were interested in digital image analysis. Civil engineers were interested in the surveying and mapping aspect of remote sensing. Foresters and agricultural scientists were interested in applications to their sciences. Physical Geographers were perhaps the best equipped because of the interdisciplinary nature of their science. It is extremely difficult in the universities to organize along interdisciplinary lines.

Richard Protz

Ellsworth LeDrew

A remote sensing group under Prof. Bonn of the Geography Department of the University of Sherbrooke got an early start. This centre under the name of CARTEL has grown to a permanent staff of about 20 people and has spun off a number of private companies.

John Wightman

Individual professors in Memorial, Dalhousie, U.N.B., Laval, Univ. of Montreal, Ottawa U., Ryerson, Windsor, Univ. of Manitoba, Saskatchewan, Calgary, Edmonton, U.B.C. and Victoria all teach remote sensing from the point-of-view of an individual discipline.

In its formative years, CCRS was fortunate in being able to obtain the services of Phillip A. Lapp Ltd. and the late Donald J. Clough, of the Systems Engineering Department , University of Waterloo. Working as a team they provided invaluable advice on CCRS management and organization. They also served on Working Groups and attended the annual meetings of the Canadian Advisory Committee on Remote Sensing giving papers and providing advice to working groups.

Archie McQuillan

These reports prompted Don Clough to obtain funding from NATO to conduct an international symposium for 'Earth Observation and Environmental Control' to which 26 of the world's leading experts in this field were invited in Nov. 1976. Plenum Press published the proceedings, edited by Clough and Morley, in 1977. Philip Lapp in the same year promoted another NATO symposium dealing with Arctic Systems, also published by Plenum Press in 1977. This report, discipline-wise, was more general in scope, but dealt solely with Arctic matters which were of prime interest to both National Defence and the petroleum industry which were more than usually interested in the Arctic at that time. As recently as 1990, I had a request from Dr. Solandt to send him a copy of a paper published by Morley and Clough on a proposal for a multidisciplinary Arctic operations centre given at that symposium. One of the obvious features of both the Arctic and East Coast neartime surveillance operations is that surveillance data acquired by the various responsible agencies is not shared in a timely manner. Obviously this calls for joint operations centres, but so far they have not happened.

Archie McQuillan, the in-house CCRS expert on systems design, cost/benefit analysis and operations research, prepared several reports that were extremely valuable to CCRS management from a strategic planning point-of-view. They are:

Dec. '74:

Benefits of Remote Sensing in Canadian Northern Resource Development (all aspects)

The Value of Remote Sensing in Canadian Frontier Petroleum Operations

Applications and Potential Benefits of Landsat - D

The latter report was done in justification of CCRS investing in considerable upgrade hardware and software in anticipation of NASA orbiting a new and improved version of Landsat.

In retrospect I believe that these reports should have received wider distribution, as they were more useful than just for program justification - there is the makings of a very useful textbook on remote sensing applications in all these reports.

Having served in WW II as a radar specialist and having seen some of Harky Cameron's 'secret' SLAR data from the RAF in the early '60s, I was naturally interested, even in the planning office stages, in the possibility of radar imaging from space. I consulted Chapman's spacecraft technology experts and was told that SLAR would not be feasible from space, because it would require too much power and too big an antenna to achieve any decent ground resolution, so I gave the idea up until 1972 when I attended an international conference on space, (in, of all places, Azerbaijan, U.S.S.R.), sponsored by the International Astronautical Federation. To my amazement, a NASA scientist gave a paper on a new satellite they were planning (I thought that such a paper would have been classified by the U.S. Military). It was to be called SEASAT and was to contain three sensors--a synthetic aperture radar with a ground resolution of 20 metres (he didn't explain the concept of' synthetic aperture' which did not require nearly as much power as a real aperture radar and mysteriously had a ground resolution which was independent of range!). Another sensor was a radar scatterometer, which operated at a frequency which was selectively responsive to the wave length of wavelets on the surface of seawater (this allowed the measurement of surface winds in strength and direction). The third was a radar altimeter, capable of determining the distance between the satellite and the sea surface to within an accuracy of five centimetres (it was to be used for measuring sea state and geodetic bulges and indentations in the Earth's crust).

Upon returning home, I immediately asked NASA if we could also read out SEASAT at Prince Albert. They said that Canada cannot expect to read out every remote sensing satellite that NASA puts up unless we contributed technically to the program. They asked if we could contribute the radar antenna. I replied yes, I thought so, but would have to check. I enquired from a NASA scientist at the working level and he said NASA had already let the contract to make the antenna. Again, it seems, they were not too anxious for a foreign country to be reading out one of their experimental satellites which, of course, is understandable. On the other hand, we wanted to ensure that we had direct access to data of Canada. I delivered a paper in Strasbourg sponsored by the European Space Agency on the importance of satellite radar and some of its applications. There didn't seem to be too much interest in the paper except from the U.K. However soon after, ESA requested NASA to allow them to read out SEASAT and eight years later in 1991 ESA launched its own experimental radar satellite ESA, using Canadian technology to digitally process their data. After ESA requested readout privileges for SEASAT, NASA relented and allowed both CANADA and ESA to read out.

Preparations began in 1974 for Canada to read out SEASAT. Both the Shoe Cove, Nfld. and Prince Albert Satellite Stations had to be modified to read out X-band, the downlink frequency. Canada also had to decide on what kind of a SAR data processor to use. JPL (Jet Propulsion Lab), the NASA SEASAT manager had decided on an optical laser processor using the ERIM technology. Keith Raney and Ed Shaw felt that Canada could develop a digital SAR processor and let a contract to MDA to develop it. MDA was successful in producing the World's first digital SAR processor both for aircraft and satellite use. This processor was eventually used by JPL for SEASAT SAR and by Intera for their STAR-1 airborne radar.

On the user side, it was decided to run a SAR validation program that we called SURSAT (surveillance satellite). Thirty-five (35) test areas were selected over various types of terrain and ocean, and the plan was to underfly SEASAT with our airborne radar at the same time as the satellite was passing overhead. Plans were made to take ground truth data at the same time.

SEASAT was launched in August 1978, but due to a massive short-circuit in one of the slip ring assemblies that was used to connect the rotating solar arrays into the electrical system, the satellite failed on Oct. 10th, '78, after satisfactory operation in orbit for 105 days. There were about 126 orbits in which SAR data was partially recorded over Canada, but unfortunately few of these were over our prescribed test areas. Fortunately for Canada, we still had our airborne SURSAT program which we decided to go ahead without the satellite. A whole new program was designed under contract to Intera.

In 1979 when it became evident that NASA was not going to launch SEASAT-2 as they said "they did not know enough about how to interpret the data and wanted to do more research on this before launching the next radar satellite", the Working Group on Satellites and Ground Station Engineering recommended that Canada now had enough knowledge about SAR radar to be able to make its own radar satellite, and that we should do so. This recommendation was taken up to the Interagency Committee on Remote Sensing which, to my surprise, approved it and sent it on to Cabinet. That was 16 years ago!

A special RADARSAT Project Office was set up in 1980. Ed Shaw took over as manager, Keith Raney as chief scientist and Bob Warren from DOC in charge of spacecraft engineering. The project office was supported by secondees from DOC, Environment Canada and several other agencies. SPAR Aerospace was selected as prime contractor supported by MDA and COM DEV who are responsible for the SAR sensor. Several other companies are involved as sub-contactors.

These scientists and engineers have devoted a major part of their careers to this project. Most of the set-backs were not technical but were political and financial. The U.K. had promised to supply the spacecraft bus and later withdrew. After arrangements were made for another bus, the Government decided the whole project was too expensive. Phil Lapp led a group from the contractors who made a proposal for a 'stripped-down' version that finally got approval. Present plans are for a launch by early 1995. (Editor's note: RADARSAT was successfully launched in November 1995.) This satellite is now at the top of the priority list for the Canadian Space Agency. The Canadian Space Agency is responsible for the space segment and CCRS for the ground segment.

RADARSAT International, a consortium of SPAR Aerospace, MDA and COM DEV won the bid to handle the marketing and sales of the RADARSAT data. Later they also took over marketing for all remote sensing satellite data in Canada and have made agreements with the two other international distributors of remote sensing data, SPOTIMAGE of France and EOSAT of the U.S to market their data in Canada.

To promote the use of the RADARSAT data, CCRS has run a program entitled 'The Radar Data Development Program' (RDDP). It consisted of the letting of competitive contracts totalling $ 5 M. per year for up to 15 years and was begun in 1987. These projects have been mostly in the applications area. RADARSAT International is also running a vigorous international promotional campaign to market the data. The commercial success of RADARSAT will depend upon these two programs.

When Canada proposed reading out NASA's ERTS satellite in 1968, very little was known about digital image analysis. Techniques for 'stretching' the data to obtain enhancements within limited spectral limits was known such as, for example stretching the spectral resolution in the green-blue area to enhance the water features (leaving the land part of the image white and featureless). It was also known how to geometrically correct an image first by using information on the attitude of the spacecraft at the time the image was acquired (system correction) and then using photo 'chips' of easily-identified points on the ground (ground control points), whose geodetic positions were accurately known, to warp the raw image by digital manipulation of the pixel positions to fit these points (precision correcting). Crude methods were also known for making atmospheric corrections. All these corrections were supposed to be done automatically before the hardcopy was made for distribution. It was assumed that all data interpretation would be done from colour prints or transparencies by 'eyeball' using standard airphoto interpretation techniques.

Paul Pearl

Dick Economy did not take this lying down. In 1976, he left G.E. and set up a company with Willoughby in Toronto by the name of OVAAC-8. They proceeded to develop image analysis software that would work on a standard VAX computer manufactured by Digital Equipment. When the IBM PC came out they converted the software to run on a PC. As the software had virtually the same capabilities as the hard-wired ARIES equipment, it eventually spelled the demise of DIPIX. OVAAC-8 was sold to PCI in 1985, the presidency of which was taken over by Murray Strome from CCRS. In 1990 PCI under the new presidency of Dr. Bob Moses took over DIPIX. PCI is now the number two world supplier of remote sensing image analysis software, led only by ERDAS of Atlanta. For a time MDA had entered the field, but did not find it as profitable as their other business, so gave it up.

(Editor's note: Since the time of this publication by Dr. Morley, the ownership, position and partnerships of the companies mentioned, may have changed appreciably.)