Seminar and Workshop on photogrammetry and land information systems (LIS)

Photogrammetria (PRS), 43 (1989) 347-349

347

Elsevier Science Publishers B.V., Amsterdam - - Printed in The Netherlands

REPORTS Reports for publication in this section are requested to be mailed to the Reports Editor Prof. Dr. John Trinder, School of Surveying, University of NSW, Kensington, N.S.W. 2033-Australia, phone + 61-2-697 222-X4197, telex + 71-260 54 unreg.

Seminar and Workshop on P h o t o g r a m m e t r y and Land Information Systems (LIS) 6-17 March 1989, Lausanne - Switzerland This international meeting was organised by Professor Otto K51bl at the Swiss Federal Institute of Technology (EPFL), some 6 km west of the city of Lausanne, close to the northern shore of Lake Geneva. The meeting was arranged so that participants could attend the seminar (week 1 ), or the workshop (week 2), or both. Numbers for the workshop were limited because of the intention to allow hands-on access to a limited range of equipment. In the event some 150 colleagues from 17 countries took part in the seminar, and 50 remained for the workshop the following week. Apart from the Swiss hosts, the largest contingents came from Denmark, Italy, West Germany and France. Participants included a substantial number of professors in various disciplines, other academics and experienced practitioners from both the government and private sectors. Four carefully chosen manufacturers had accepted Prof KSlbl's challenge to subject their GIS and Photogrammetric systems to prolonged scrutiny by this critical audience and strong teams were on hand both to present their own products and to examine those of their rivals! Clearly, some organisations saw this meeting as a good opportunity for continuing education for their staff; however, the general level and range of knowledge, experience and creativity was such as to promote a stimulating discussion in every session. The main languages of the meeting were Franch and English. During the seminar only, simultaneous translation was provided from each to the other, and from German into both. For demonstrations and workshop sessions, English, French and German language groups were catered for. The administrative arrangements worked well and promoted a pleasantly relaxed atmosphere despite the long hours of work customary in Switzerland. With very few exceptions, speakers had been persuaded to provide their papers in advance. It is intended that the proceedings {including discussion) will be published by EPFL later in 1989. My overriding impressions from the seminar were the following: (a) Firstly, that LIS/CIS represents a rapidly expanding new field which professional land surveyors must master but which needs to adopt standard terminology to improve communication of its ideas. The vendors would have us believe that the cost of the technology is negligible compared with the costs of initial data capture and database creation and maintenance; many users are prepared to make the same assertion. (b) Secondly, that my own organisation, the Ordnance Survey of Great Britain (OS), by virtue of its already large digital map archive, is in the vanguard of those facing the challenge of digital map management and maintenance today. However, our problems, arising from the varied history of our maps, especially at the 1 : 2500 scale covering most rural areas, are far from unique: all round Europe 19th century cadastres are being digitised, updated and merged with national topographic maps and very similar problems are being addressed. Our counterparts can learn from us and we from them. From the workshop comes the perhaps disappointing impression that sensible tasks cannot be set up for single-day exercises starting from scratch on elaborate high-technology equipment, even

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348 with small groups of well qualified people. The most that can be attempted is a well-guided and quite advanced demonstration with hands-on activity and a fruitful dialogue between demonstrator and participants. Once both participants and vendors had grasped this the workshop week became a rewarding experience and each day proved more successful than the last. Other groups (tackling systems in a different order ) reported similar experiences so my broad impression of an ascending order of merit in the systems examined is certainly not fair to the one seen on the first day! The first day of the seminar addressed the basic principles ofa LIS, discussing in turn databases, topology and data output and data exchange. R. Spooner (Heerbrugg) drew together topological theory and the topology implicitly recognised by all skilled map users, to support the transition from maps as pictures to the GIS requirements for maps as databases. M. Marini (Bologna), with the benefit of his company's first-hand experience of many of the existing GIS products, discussed practical problems of data exchange and the merger of different datasets. He proved to be an enthusiast for the British National Transfer Format (NTF); judging from audience response during the week NTF seems to be on the way towards wide acceptance beyond its intended frontiers. Tuesday and Wednesday were devoted to presentations by the vendors of their GIS and photogrammetric systems. Intergraph with TIGRIS and IMA, Prime-Wild GIS with System 9, Kern with INFOCAM and their DSR analytical plotters, and Zeiss West Germany with PHOCUS and Planicomp all took their turn to introduce their latest products and philosophy in the auditorium in the mornings, and to demonstrate them to each of our four groups in the afternoon. Despite the numbers involved most of the demonstrations were well conducted and even allowed those who wished it briefly to handle the analytical plotters. It is clear that all of the GIS have evolved rapidly over the past two years and are still evolving. In view of the time lapse before this report will appear in print it would be unwise for me to comment on the relative maturity of each of the four systems as at March 1989. However, there is little doubt that the capability of Intergraph's TIGRIS "Imager" to bring together raster and vector data for manipulation on the same screen within the same database is a development which will be emulated by others and which will offer powerful tools for map revision to those who (:an aftbrd them. This convergence of interactive graphics, image processing and photogrammetry is certainly paralleled by developments under the Kern flag and doubtless other examples will soon see the light of day. Meanwhile analytical plotter developments also continue to converge, with distributed processing as pioneered by Kern now adopted by all the major vendors. All were showing superimposition systems, those on the System 9-AP and the Kern DSR 15 being demonstrated in stereoscopic form, which may possibly offer advantages over mono-systems for some applications. Only Kern were showing their automated correlation system, which thanks to the use of several transputer arrays is not achieving considerably bettter speed, accuracy and reliability than when I last saw it in 1987. It still remains to be seen when this development will finally emerge into viable production practice from the research environment. The fourth day was devoted to papers by users, Swiss in the morning and foreign in the afternoon. Kaufmann spoke about the project to renovate the Swiss eadastre, now beginning to be implemented after a ten-year study and elaborate political and legal preliminaries. This account of an ambitious national project was complemented by the efforts of J.-L. Horisberger, a private land surveyor, to bring together all the interested parties (surveyors, municipalities,utilities, civil defenee and so on) in the Montreux-Vevey region so as to create and share a LIS compatible with the eventual reformed cadastre. The foreign contributions came from K.-J. Barwinski (North Rhine Westphalia), M. Brand (Ordnance Survey of Northern Ireland) and L. Surace (Italian Geographic Military Institute). Brand's paper addressed political and financial aspects of securing support for GIS. He asserted that change from maps to information systems is inevitable; that the data, not the equipment, is

349 the major investment; and that the investment will be cost-effective if the GIS is kept up to date and is shared. The seminar ended on the Friday with a useful session on System Evaluation. Mrs J. Hvidegaard (Copenhagen) outlined the methodology used to evaluate systems for the Danish Cadastre. R. McLaren (Edinburgh) followed with a structured approach which he uses in his work as a private consultant but which is worthy of study by anyone concerned with the evaluation and procurement of GIS technology. A panel discussion bringing vendors and users together on the platform brought an interesting week to a close, with a clear desire from users for inexpensive systems and clear reluctance on the part of manufacturers to countenance them despite the ever increasing power of microprocessors and PCs. What I have long suspected merged explicitly here: the vendors' policies vary from aiming to release only fully-fledged systems, to expecting their early customers to participate heavily in system development. Although neither approach succeeds totally, each has some merit; to avoid disappointments it is important that the users understand which policy they are purchasing. The aim of the workshop in the second week was to allow small groups (12 to 14) to spend almost a whole day with each vendor, doing group exercises on the two pieces of equipment being shown by each. This was intended to allow hands-on experience for every individual, and realistic work under the headings project definition, graphic presentation, data handling and data editing. In the event even those vendors who had prepared special documentation as a framework for an exercise found that the best that was possible was a thorough demonstration. In addition to those demonstrations, on three mornings EPFL researchers presented papers on their work. Finally, the last morning was devoted to the only true group exercise of the week when each team, with one vendor's representative attached, addressed an agreed GIS requirement. The demonstrations varied considerably in their effectiveness but the best were clearly satisfying both for participants and vendors. At worst, even quite innocent questions from sympathetic audiences led to system or demonstrator failure. Plainly even the most sophisticated systems still have their shortcomings. In subsequent discussion vendors' representatives claimed with some justification that systems requiring at least a fortnight of operator training that they can only be demonstrated, not tested, in the course of a day, and that too many challenges from the audience were distracting the demonstrators from showing the things that their systems already can do. After this clearing of the air both sides evidently modified their expectations and were satisfied with their eventual experiences. On the last day "case studies" led to further stimulating exchanges. Finally, D. Fritsch (Lausanne and Munich) attempted a classification of different GIS but ended with remarkably few differences, apart from the obviously different operating systems and hardware. He drew attention to the evolution from early attempts to apply CAD/CAM systems to geographical data (difficult because of edge and attribute problems) through the present generation of vector-based GIS, to the future hybrid GIS with both vector and raster capability. He also pointed to trends: increasing use of UNIX, increasing speed of hardware (towards 100 MIPS), more reliable and transparent DBMS, and increasing pressure for standards to facilitate information exchange. He concluded that those participants with big money should buy Intergraph or System 9, those with little money should by Kern or Zeiss, while the advice to those with no money was regrettably not suitable for an international scientific journal. He forebore to say who would be happiest. In conclusion I would thank Prof. KSlbl and his Institute for taking the initiative in organising such a meeting, the manufacturers for accepting the very considerable challenge, and the European participants for once again conducting a major meeting largely in English, albeit with a strong French bias which benefited those of us able to operate in either language. Paul Newby, Southampton-England