Rapid developments in engineering, microelectronics and the computer sciences have greatly changed both the instrumentation and methodology in Engineering Geodesy. The objectives of the Special Commission are on the one hand to document the body of knowledge in this field, and on the other hand to encourage new developments and present them in a consistent framework. Symposia and workshops are planned to document the current state of development in engineering applications of geodesy. Working Groups were established in areas of current research interest which will have specific goals to ensure that their research work can be accomplished in a four year period. In addition, there is considerable collaboration with other international organisations such as the ISPRS, FIG, and the ION.


SC4 WG 1: “Real-Time Mobile Multi-sensor Systems and Their Applications in GIS and Mapping”

 To fulfil the need for up-do-date inventory and geometric data along transportation routes (e.g. roads, railways, rivers, pipelines, etc.) Mobile Multi-sensor Systems (MMS) are being operated. In general, MMS have in common that they integrate a set of sensors mounted on a single platform, and synchronized to a common time base. They are typically operated in kinematic mode. In principle, they are capable of operating only with the data measured on the platform, that is, no other information (such as external ground control) is needed, although it may be included as redundant information. Systems of this type:

Can be immediately deployed anywhere on the Earth without the need for identifying existing ground control.
Employ a task-oriented system design through integration at the measurement level, and hence data flow optimisation can be a built-in feature.
Can be equipped with real-time quality control features by including data redundancies in the system design, and by using a combination of real-time data processing and Expert Knowledge to generate homogeneous results.
Generally use software geo-referencing to transform the time-dependent measurement process into a sequence of geo-referenced images, which can be considered as independent geometric units in post-mission processing.


The objectives of the Working Group are:

Identify and promote new developments in MMS.

Identify and promoted new applications for MMS.

Encourage and document emerging processing techniques for MMS.


Chairman:           Naser El-Sheimy (Canada)
Co-chairman:      Jan Skaloud (Switzerland)                                                                       (18 members)


SC4 WG 2: “Dynamic Monitoring of Buildings and System Analysis”

The world records for bridge span and building height have increased more than tenfold in the second millennium. In the 20th century alone, the record height for a building has increased from 118m to 452m, while the record for a bridge span has increased from 521m to 1991m.


As can be seen from these records, quality control of these structures is a challenging task. The goals of the monitoring methods are: assessment of the structural behaviour (safety inspection) and improvement of maintenance (optimization of repair, early detection of damage, etc.). The input for the monitoring methodes can be forced or ambient vibrations. Then "Forced Vibration Testing" (FVT) and "Ambient Vibration Testing" (AVT) can be applied.


Instruments, used to monitor the motions, are often fixed to the object under motion. That means that their dynamic parameters change depending on the frequencies of the motions. The goal of this Working Group is, to study dynamic monitoring methods, sensor systems and system analysis models for quality control of large manmade structures. Interdisciplinary collaboration will be necessary.


Chairman:           Wolfgang Niemeier (Germany)
Co-Chairman:     Rainer Flesch (Austria)                                                                           (8 members)


SC 4 WG 3: “Monitoring of Local Geodynamic Processes and System Analysis”

Monitoring and system analysis of landslides, mudflows and rockslides has become of great importance, since the population of the world is increasing dramatically and, as in many cases, housing estates and industrial sites were erected without taking these geodynamic processes into consideration.


In mountainous areas, for instance, as in the European Alps, it is estimated that about 6% of the country is affected by landslides. Along the Yangtze River in China, in the vicinity of the Three Gorges Dam Reservoir, for instance, about 100 landslide sites have to be monitored. Their average velocities can vary from 1 to 200mm/year, and in general the movements are fairly regular, especially on large slopes. In some cases there are reactions according to the climate conditions. However, sometimes instabilities are possible, which cause the velocities to be multiplied by a factor 100 and greater, sometimes resulting a disaster failure.


The main goals of the Working Group are to study:

Computer-controlled MMS recording geodetic, geophysical and meteorological data.

Different models of system analysis.

Models for disaster/failure prediction.


Chairman:           Gyula Mentes (Hungary)
Co-Chairman:     Ewald Brückl (Austria)                                               (14 members)


SC 4 WG 4: “Geodesy on Large Construction Sites”

The growing world population and the globalization of the economy demands improved traffic systems, power stations and construction of dwellings and bureau centres. Therefore in the future large construction sites will have to be managed. Geodetic methods and techniques can contribute to do this management in a most economical way. There will be large construction sites for high speed railway lines, tunnels, bridges, power dams, airports, and so on.


The main goals of the Working Group will be to study:

1.        The design of networks based on permanent GPS stations.

2.        The navigation of construction machines.

3.        High precision alignment methods.

4.        Information systems based on geodetic-geotechnical-geological data.


Chairman:           A new chairman will be nominated within two months.


SC 4 WG 5: “Pseudolite Application in Engineering Geodesy”

In satellite-based precise positioning, the dominant factors are the number and geometric distribution of the satellites tracked by the receivers. In the case of global navigation satellite systems (GNSS) such as GPS, Glonass, and the planned Galileo system, four visible satellites are the minimum requirement for precise three-dimensional positioning. In general, the more satellites that are tracked, the more reliable the positioning solutions. However, in some situations, such as in downtown urban canyons, engineering construction sites, and in deep open-cut pits and mines, the number of visible satellites may not be sufficient. In the worst situations, such as in underground tunnels and inside buildings, the satellite signals may be completely lost. Such problems with existing GNSS systems can be addressed by the inclusion of additional ranging signals transmitted from ground-based "pseudo-satellites" (pseudolites). Pseudolites are an exciting technology that can be used for a wide range of positioning and navigation applications, either as a substantial augmentation tool of spaceborne systems, or as an independent system for indoor positioning applications.

The goal of this proposed Working Group is to study new concepts of pseudolite-related positioning and, in particular, applications of pseudolites in engineering geodesy. Major objectives of the research activities are to study:

1.        Pseudolite augmentation of GPS system.

2.        Pseudolite-only positioning scenarios.

3.        Integration of pseudolites with other sensors, such as INS.

These objectives will be achieved by:

·         Promoting discussions between Working Group members.

·         Setting up a Working Group website providing a focus for pseudolite research and applications with the relevant links. The web site is located at:

·         Developing a comprehensive bibliography dealing with pseudolite research and applications.


Chairman:           Jinling Wang                                                               (12 members)


SC 4 WG 6: “Application of Knowledge-Based Systems in Engineering Geodesy”

For many geo-(but also non-geo-)disciplines the results of geodetic measurements (coordinates, displacements, etc.) serve as a basis for solving problems such as interpretation, documentation, recognition, control, design, prediction, diagnose, alarming, simulation, and so on. Examples are the (intelligent) control of measurement or guidance systems, the detection of outliers, or the early recognition of noticeable patterns in the displacement data of tunnels under construction, etc. For these tasks geodetic data often must be considered incomplete and uncertain, and in most cases additional knowledge from experts of the specific application field is needed.


Nowadays there is a growing demand for geodesists to work in interdisciplinary teams and to contribute to the development of appropriate systems and techniques that help to solve these problems in a more 'intelligent' and 'automatic' manner. The application of AI-methods, such as Knowledge-based Systems, seems to be a promising approach, gence this research for, and applicability in, Engineering Geodesy will be the main objective of the Working Group.


Chairman:           Klaus Chmelina                                                           (5 members)


Conference Activities

 WG 1 was organiser of the conference "3rd International Workshop on Mobile Mapping Technology", 3-5 January, 2001 in Cairo, Egypt. A report on the conference can be downloaded from the SC4 websites.

Websites:                                http://info.tuwien.ac.at/ingeo/sc4/sc4_99-03.htm



Working Groups WG 2 and WG 3 have organised a workshop on "Monitoring of Constructions and Local Geodynamic Processes", held in Wuhan, P.R. China, from 22-24 May, 2001.

        Websites:                                http://info.tuwien.ac.at/ingeo/sc4/wuhan01.htm



The Special Commission is co-sponsor of the "5th Conference on Optical 3-D Measurement Techniques", which will be held in Vienna, Austria, 1-4 October, 2001.

        Websites:                                http://info.tuwien.ac.at/ingeo/optical3d/o3d.htm



The Special Commission is organising the "2nd Conference on Geodesy for Geotechnical and Structural Engineering", which will be held in Berlin, Germany, 21-24 May, 2002. This will be the meeting where all the WGs will come together to present their scientific programs and report on their current research work.

      Websites:                                http://info.tuwien.ac.at/ingeo/sc4/berlin.html



TABLE OF CONTENTS                                                          TOP