- Email: [email protected]
ISPRS commission IV symposium
44
sualisation techniques as shown by Alexandra Fonseca (CNIG-Portugal) with the use of morphing to visualise environmental impact assessments, and by Constantin Boytscheff (University of Stuttgart) who showed the full potential of integrating animated CAD images to visualise alternative development proposals.
Data structuring and resource organisation. These issues were raised by several presentations. Among them, Dimitris Sardelianos and Vassilis Pappas from the University of Patras used the example of the Great Cities of Europe project to illustrate how data can be structured so that in overlaying regions that have text or image attachments the existing links are developed and maintained. Object-Orientation to solve some of the existing indexing problems of MM data was advocated by Patrice Boursier of the Paris-Sud University and illustrated with a set of examples which used hypermedia navigation tools to integrate vector and raster data. While these presentations focused more on computer programming solutions, David Di Blase of PennState University focused on the pre-development stage of a MM project when careful consideration must be given to the resources to be utilised and their purpose. Taking as example the development of a MM supplement for a university textbook, David introduced a typology of different resource types (images, maps, diagrams, graphs, and tables) and functions required (static, animation, sequential, hierarchical, and conditional or rule-based). The ensuing matrix allows a structured planning and management of extensive MM development projects. Spatial analysis and simulation/modelling. The integration of GIS and MM (or MM and GIS?) promises to yield considerable benefits for spatial analytical processes. This was clearly demonstrated by a range of prototypes presented by Henk Scholten and Bijtetar Bas (Geodan) to assist decision-making in industry, business, and the leisure industry. In respect to the latter, the system developed for the Dutch Tourist Board gave a useful example of spatial analysis performed by GIS and presented via MM. The opposite perspective was presented by Jonathan Raper and David Livingstone (University of London), who start from a MM system in which they georeference video footage, and then build in GIS functions via high-level programming language linked into Hypertalk/Hypercard. The resulting system allows to store into buttons both the geometric attributes of MM data and basic spatial function such as length and area calculation. The use of GIS and MM to simulate hypothetical scenarios was presented by Einar Veirum from the Danish Technological Institute. His distributed system integrating media types (maps, sound, images, text) and communication means (telephone, fax, etc.) allows
ISPRS Journal of Photogrammetty and Remote Sensing to train a large number of officers and managers in the emergency services. Within a controlled environment, "almost real" situations are set up which trigger real action from individuals and organisations, such as sending out rescue teams, monitoring their progress, etc. This "organisational intensive" application contrasted nicely with a computational intensive one presented by Nelson Neves from Novasoft, Portugal. His integration of GIS and Virtual Reality offered a glimpse of this frontier-area of research, which promises to open new ways of exploring data and phenomena in a highly interactive way.
Conclusions and research agenda This brief overview of the Rostock meeting gives a flavour of what has been a highly interactive and enjoyable research meeting, All participants felt that there was a real need to have a long, focused meeting on GIS and MM research to take stock of what is being done in various countries and disciplinary areas and define new research areas on which to concentrate efforts. As a result of the discussions during the meeting and a "pyramid" process of negotiations, the participants, identified the following topics as the most urgent for future research: • Data organisation and structuring • Evaluation of the use and value of MM • MM and spatial analysis • Human-computer interaction/methods of interaction To develop this research agenda it was agreed to continue the collaboration and exchange of ideas among the participants via e-mail, to organise a conference in 1995 on GIS ~ Multimedia to expand the research network and promote dialogue with industry in this research field, and to set up a forum on Internet for the comparison and evaluation of MM products. The outputs of the Rostock meeting will include an edited video of the demonstrations held, and the publication of groups of papers on international journals such as IEEE Multimedia, IJGIS, and Environment Planning B, whose editors have expressed an interest in developing theme issues on this subject. More information on the GISDATA programme can be obtained from Dr. Max Craglia, Dept. of Town Regional Planning, University of Sheffield, Sheffield $10 1TN, UK, Tel. +44-742-720 185, Fax +44-742-722 199. M. Craglia (Sheffield, UK)
ISPRS Commission IV Symposium May 31 - - June 3, 1994, Athens, Georgia, USA The Symposium of ISPRS Commission IV was held on May 31-June 3, 1994, at Athens, Georgia, USA, co-organized by the Center for Remote Sensing and
Volume 49, number 5, 1994
Mapping Science (CRMS) and the Georgia Center for Continuing Education of The University of Georgia. The Symposium was attended by approx. 200 participants from 26 countries. Presentations were organized in seven main topics, covering all Commission-IV-related working groups. Regarding GIS data and applications (WG IV/l), a large variety of papers were presented, ranging from land cover classification, land use change detection and analysis of metropolitan area expansions to monitoring air pollution and analyzing marine waters. The important issue was the integration of raster and vector data, GPS, remote sensing, digital image processing and GIS technologies in a framework for a feature-based approach to GIS. Issues emphasized by this integration include the proper organization and management of the associated huge amounts of data for easily accessing features across multiple overlapping databases and multiple geometries. Applications need not be restricted to aerial imagery, as the successful integration of GPS technology with digital photogrammetry in a moving vehicle clearly demonstrates. Presentations in the area of international mapping from space (WG IV/2) dealt with three-dimensional measurements and the mapping potential of major systems like MOMS, JERS-1, MEOSS, OPS, ASTER and SPOT, especially considering their role as sources for topographic data in a global scale. Issues addressed included the desired ground resolution of these systems, and their stereo capability. It was emphasized that stereo data availability is very important for orthophoto correction and production, DTM data collection and, in general, 3-D database generation. The use of interferometric radar techniques (i.r.t.) for DTM collection was also addressed, with the general consensus being that basic research is still needed in this area. However, i.r.t, advantages, such as cloud and in general weather independence, and a relative shortening of the required data collection time are extremely important, making i.r.t, very promising. The working group presentations were followed by a very interesting and valuable panel discussion of leading experts, evaluating the current status of research in this area. Examining ground resolution as it is dictated by the user's requirements and considering 1:50,000 and 1:25,000 mapping applications, 5 m and 1 m ground resolutions were deemed appropriate. The panel emphasized the importance of the availability of stereo data as well. WG IV/3 dealt with changes in the map and database revision processes, mainly brought on by recent advancements in digital photogrammetry. Issues emphasized in Athens were the complex role of digital orthoimages within modern-day GIS (even though officially this is a subject of WG IV/4), and the automation of topographic database revision through semi-automatic procedures for object extraction from
45 digital imagery. The presented papers demonstrated the rapidly changing status of topographic database production, management and updating, as fundamental digital photogrammetric research is starting to have a grave impact on the production level of the photogrammetric procedure. The importance of this can be witnessed by the fact that this (WG IV/3) was the working group with the highest author participation, with a total of 32 oral and poster presentations. This change is also pointing towards a more active role of digital photogrammetric workstations (however loosely they may be defined) for database updating, a role which is obviously tied to that of digital imagery within modern GIS. The presentations of both concepts and systems showed that change is imminent, indeed arriving, in this field. At the same time, a more realistic approach is followed, pursuing efficient automated methods and systems, rather than aiming for a, currently utopic one might argue, full automation. Regarding DEMs and digital orthoimages for mapping/GIS applications (WG IV/4), besides issues already addressed by WG IV/3, major issues included the automatic DTM and orthophoto generation, the extension of classic DTM concepts to full 3-D by functionally incorporating buildings and other vertically extending features. Similar issues related to 3-D topographic databases in general, and the combination of vector and raster data in hybrid GIS, an issue especially important for the optimal incorporation of digital orthoimages into GIS. Other presentations confirmed the applicability of matching methods for automatic DTM generation, using images from both aerial and satellite-based sensors. As an example, accuracies in the order of 5-10 m using SPOT imagery, and better than 0.01% of the flying height for aerial cases were reported, while the importance of pyramidal strategies for robust solutions under unfavourable terrain conditions was reconfirmed, together with the importance of proper satellite models to avoid systematic errors. Complementing image-based methods, laser scanning can provide an efficient solution to DTM generation in forest areas, offering accuracies of 10-15 cm. Working groups IV/5 and IV/6 attracted fewer presentations than the other groups, but were quite interesting nevertheless. Presented research activities on extraterrestrial mapping (WG IV/5) dealt with the modification of matching for application to extraterrestrial imagery, considering the particularities of the specific imaging geometry, and the design of GIS to combine global datasets and various measurements for any planetary body. Presentations regarding GIS and expert systems for global environment databases (WG IV/6) focused on the integration of remote sensing and GIS for global applications, such as monitoring ecotone boundaries, desertification trends, evapotranspiration and global environmental studies in general.
46
Regarding conceptual aspects of GIS (IC WG III/ IV), the integration of remotely sensed images and scene understanding techniques within a GIS framework received again large attention. The translation of decision currently made within an image processing environment into GIS information is a key issue. The GIS-digital imagery relationship though does not have to be a one-dimensional one. Already existing GIS knowledge can be used to facilitate the automatic interpretation of remotely sensed images. At the same time, the inclusion of data quality parameters in a GIS (expressing, e.g., positional accuracy) presents the engineering point of view into GIS. The substantial advancements in digital photogrammetry, emphasized by the unique automation potential offered by the availability of imagery in digital format are slowly but steadily affecting production, with mapping being influenced the most. The overall mapping process is currently in a dynamic phase, evolving towards its automated, digital future. The Symposium successfully captured this state, providing
ISPRS Journal of Photogrammetry and Remote Sensing a nice overview of relevant developments, emphasizing the trend towards the integration of digital photogrammetric methods and principles with GIS concepts and applications, and offering valuable insight on what is to be expected in the near future. At the same time, the obvious was reconfirmed: photogrammetric processes provide the ideal solution to the GIS need for frequent data updates. The Symposium Proceedings were published as Vol. 30, Part 4 of the series of InternationalArchives of Photogramrnetry and Remote Sensing and can be obtained by contacting the ASPRS store, RO. Box 1504, Cranberry Township, PA 16066-0504, tel. + 1 (412) 7720099, fax +1 (412) 7725281. This 710-page volume, edited by Prof. Roy Welch and Dr. Marguerite Remillard, is of the standard high quality characterizing the ISPRS Proceedings, the only remark being the absence of an author and/or subject index, much needed in a volume of such a size. P.Agouris and M. Meister (Zurich, Switzerland)
sualisation techniques as shown by Alexandra Fonseca (CNIG-Portugal) with the use of morphing to visualise environmental impact assessments, and by Constantin Boytscheff (University of Stuttgart) who showed the full potential of integrating animated CAD images to visualise alternative development proposals.
Data structuring and resource organisation. These issues were raised by several presentations. Among them, Dimitris Sardelianos and Vassilis Pappas from the University of Patras used the example of the Great Cities of Europe project to illustrate how data can be structured so that in overlaying regions that have text or image attachments the existing links are developed and maintained. Object-Orientation to solve some of the existing indexing problems of MM data was advocated by Patrice Boursier of the Paris-Sud University and illustrated with a set of examples which used hypermedia navigation tools to integrate vector and raster data. While these presentations focused more on computer programming solutions, David Di Blase of PennState University focused on the pre-development stage of a MM project when careful consideration must be given to the resources to be utilised and their purpose. Taking as example the development of a MM supplement for a university textbook, David introduced a typology of different resource types (images, maps, diagrams, graphs, and tables) and functions required (static, animation, sequential, hierarchical, and conditional or rule-based). The ensuing matrix allows a structured planning and management of extensive MM development projects. Spatial analysis and simulation/modelling. The integration of GIS and MM (or MM and GIS?) promises to yield considerable benefits for spatial analytical processes. This was clearly demonstrated by a range of prototypes presented by Henk Scholten and Bijtetar Bas (Geodan) to assist decision-making in industry, business, and the leisure industry. In respect to the latter, the system developed for the Dutch Tourist Board gave a useful example of spatial analysis performed by GIS and presented via MM. The opposite perspective was presented by Jonathan Raper and David Livingstone (University of London), who start from a MM system in which they georeference video footage, and then build in GIS functions via high-level programming language linked into Hypertalk/Hypercard. The resulting system allows to store into buttons both the geometric attributes of MM data and basic spatial function such as length and area calculation. The use of GIS and MM to simulate hypothetical scenarios was presented by Einar Veirum from the Danish Technological Institute. His distributed system integrating media types (maps, sound, images, text) and communication means (telephone, fax, etc.) allows
ISPRS Journal of Photogrammetty and Remote Sensing to train a large number of officers and managers in the emergency services. Within a controlled environment, "almost real" situations are set up which trigger real action from individuals and organisations, such as sending out rescue teams, monitoring their progress, etc. This "organisational intensive" application contrasted nicely with a computational intensive one presented by Nelson Neves from Novasoft, Portugal. His integration of GIS and Virtual Reality offered a glimpse of this frontier-area of research, which promises to open new ways of exploring data and phenomena in a highly interactive way.
Conclusions and research agenda This brief overview of the Rostock meeting gives a flavour of what has been a highly interactive and enjoyable research meeting, All participants felt that there was a real need to have a long, focused meeting on GIS and MM research to take stock of what is being done in various countries and disciplinary areas and define new research areas on which to concentrate efforts. As a result of the discussions during the meeting and a "pyramid" process of negotiations, the participants, identified the following topics as the most urgent for future research: • Data organisation and structuring • Evaluation of the use and value of MM • MM and spatial analysis • Human-computer interaction/methods of interaction To develop this research agenda it was agreed to continue the collaboration and exchange of ideas among the participants via e-mail, to organise a conference in 1995 on GIS ~ Multimedia to expand the research network and promote dialogue with industry in this research field, and to set up a forum on Internet for the comparison and evaluation of MM products. The outputs of the Rostock meeting will include an edited video of the demonstrations held, and the publication of groups of papers on international journals such as IEEE Multimedia, IJGIS, and Environment Planning B, whose editors have expressed an interest in developing theme issues on this subject. More information on the GISDATA programme can be obtained from Dr. Max Craglia, Dept. of Town Regional Planning, University of Sheffield, Sheffield $10 1TN, UK, Tel. +44-742-720 185, Fax +44-742-722 199. M. Craglia (Sheffield, UK)
ISPRS Commission IV Symposium May 31 - - June 3, 1994, Athens, Georgia, USA The Symposium of ISPRS Commission IV was held on May 31-June 3, 1994, at Athens, Georgia, USA, co-organized by the Center for Remote Sensing and
Volume 49, number 5, 1994
Mapping Science (CRMS) and the Georgia Center for Continuing Education of The University of Georgia. The Symposium was attended by approx. 200 participants from 26 countries. Presentations were organized in seven main topics, covering all Commission-IV-related working groups. Regarding GIS data and applications (WG IV/l), a large variety of papers were presented, ranging from land cover classification, land use change detection and analysis of metropolitan area expansions to monitoring air pollution and analyzing marine waters. The important issue was the integration of raster and vector data, GPS, remote sensing, digital image processing and GIS technologies in a framework for a feature-based approach to GIS. Issues emphasized by this integration include the proper organization and management of the associated huge amounts of data for easily accessing features across multiple overlapping databases and multiple geometries. Applications need not be restricted to aerial imagery, as the successful integration of GPS technology with digital photogrammetry in a moving vehicle clearly demonstrates. Presentations in the area of international mapping from space (WG IV/2) dealt with three-dimensional measurements and the mapping potential of major systems like MOMS, JERS-1, MEOSS, OPS, ASTER and SPOT, especially considering their role as sources for topographic data in a global scale. Issues addressed included the desired ground resolution of these systems, and their stereo capability. It was emphasized that stereo data availability is very important for orthophoto correction and production, DTM data collection and, in general, 3-D database generation. The use of interferometric radar techniques (i.r.t.) for DTM collection was also addressed, with the general consensus being that basic research is still needed in this area. However, i.r.t, advantages, such as cloud and in general weather independence, and a relative shortening of the required data collection time are extremely important, making i.r.t, very promising. The working group presentations were followed by a very interesting and valuable panel discussion of leading experts, evaluating the current status of research in this area. Examining ground resolution as it is dictated by the user's requirements and considering 1:50,000 and 1:25,000 mapping applications, 5 m and 1 m ground resolutions were deemed appropriate. The panel emphasized the importance of the availability of stereo data as well. WG IV/3 dealt with changes in the map and database revision processes, mainly brought on by recent advancements in digital photogrammetry. Issues emphasized in Athens were the complex role of digital orthoimages within modern-day GIS (even though officially this is a subject of WG IV/4), and the automation of topographic database revision through semi-automatic procedures for object extraction from
45 digital imagery. The presented papers demonstrated the rapidly changing status of topographic database production, management and updating, as fundamental digital photogrammetric research is starting to have a grave impact on the production level of the photogrammetric procedure. The importance of this can be witnessed by the fact that this (WG IV/3) was the working group with the highest author participation, with a total of 32 oral and poster presentations. This change is also pointing towards a more active role of digital photogrammetric workstations (however loosely they may be defined) for database updating, a role which is obviously tied to that of digital imagery within modern GIS. The presentations of both concepts and systems showed that change is imminent, indeed arriving, in this field. At the same time, a more realistic approach is followed, pursuing efficient automated methods and systems, rather than aiming for a, currently utopic one might argue, full automation. Regarding DEMs and digital orthoimages for mapping/GIS applications (WG IV/4), besides issues already addressed by WG IV/3, major issues included the automatic DTM and orthophoto generation, the extension of classic DTM concepts to full 3-D by functionally incorporating buildings and other vertically extending features. Similar issues related to 3-D topographic databases in general, and the combination of vector and raster data in hybrid GIS, an issue especially important for the optimal incorporation of digital orthoimages into GIS. Other presentations confirmed the applicability of matching methods for automatic DTM generation, using images from both aerial and satellite-based sensors. As an example, accuracies in the order of 5-10 m using SPOT imagery, and better than 0.01% of the flying height for aerial cases were reported, while the importance of pyramidal strategies for robust solutions under unfavourable terrain conditions was reconfirmed, together with the importance of proper satellite models to avoid systematic errors. Complementing image-based methods, laser scanning can provide an efficient solution to DTM generation in forest areas, offering accuracies of 10-15 cm. Working groups IV/5 and IV/6 attracted fewer presentations than the other groups, but were quite interesting nevertheless. Presented research activities on extraterrestrial mapping (WG IV/5) dealt with the modification of matching for application to extraterrestrial imagery, considering the particularities of the specific imaging geometry, and the design of GIS to combine global datasets and various measurements for any planetary body. Presentations regarding GIS and expert systems for global environment databases (WG IV/6) focused on the integration of remote sensing and GIS for global applications, such as monitoring ecotone boundaries, desertification trends, evapotranspiration and global environmental studies in general.
46
Regarding conceptual aspects of GIS (IC WG III/ IV), the integration of remotely sensed images and scene understanding techniques within a GIS framework received again large attention. The translation of decision currently made within an image processing environment into GIS information is a key issue. The GIS-digital imagery relationship though does not have to be a one-dimensional one. Already existing GIS knowledge can be used to facilitate the automatic interpretation of remotely sensed images. At the same time, the inclusion of data quality parameters in a GIS (expressing, e.g., positional accuracy) presents the engineering point of view into GIS. The substantial advancements in digital photogrammetry, emphasized by the unique automation potential offered by the availability of imagery in digital format are slowly but steadily affecting production, with mapping being influenced the most. The overall mapping process is currently in a dynamic phase, evolving towards its automated, digital future. The Symposium successfully captured this state, providing
ISPRS Journal of Photogrammetry and Remote Sensing a nice overview of relevant developments, emphasizing the trend towards the integration of digital photogrammetric methods and principles with GIS concepts and applications, and offering valuable insight on what is to be expected in the near future. At the same time, the obvious was reconfirmed: photogrammetric processes provide the ideal solution to the GIS need for frequent data updates. The Symposium Proceedings were published as Vol. 30, Part 4 of the series of InternationalArchives of Photogramrnetry and Remote Sensing and can be obtained by contacting the ASPRS store, RO. Box 1504, Cranberry Township, PA 16066-0504, tel. + 1 (412) 7720099, fax +1 (412) 7725281. This 710-page volume, edited by Prof. Roy Welch and Dr. Marguerite Remillard, is of the standard high quality characterizing the ISPRS Proceedings, the only remark being the absence of an author and/or subject index, much needed in a volume of such a size. P.Agouris and M. Meister (Zurich, Switzerland)