After the annexation of Austria into the German Reich the “Berufsordnung der Offentlich bestellen Vermessungsingenieure“ (ObVI) was introduced in 1940. By analysis of documents in the German Federal Archives (Berlin) statements about the political orientation of the profession and the licensing procedure are possible. Within the group of ObVI the former “Ingenieurkonsulenten fur Vermessungswesen“ were the third largest group. The surveyors had to take the licensing procedure or they had to close their offices. The number of finally approved ObVI's is significantly lower than the number of independent surveyors in Austria in 1938. The result of the approval process was like in German Empire since 1938 a market adjustment. As part of the process, the political reliability and the ancestry of the candidates has been verified. In some cases, the authorization was denied for political reasons. In most cases, the rejection was based on age or lack of skills.

High accuracy 3D representation and monitoring of objects is receiving increasing interest both in science and industrial applications. Up to now tasks like monitoring of building displacements or deformations were solved by means of artificial targets on the objects of interest, although mature optical 3D measurement and laser scanning techniques are available. Such systems can perform their measurements even without targeting. This paper presents a new optical 3D measurement system, based on the fusion between a geodetic image sensor and a laser scanner. The main goal of its development was the automation of the whole measurement process, including the tasks of point identification and measurement, deformation analysis, and interpretation. This was only possible by means of new methods and techniques originally developed in the area of Artificial Intelligence; both point detection and deformation analysis are supported by decision systems that use such techniques. The resulting complex multi-sensor system is able to measure and analyse the deformation of objects, as shown in experiments. In this article we focus on specific key components and novel techniques that have been developed, and briefly report on the current stage of the whole system.

If measurements are performed without artificial targets, deformation analysis cannot refer to the points on the objects defined at an initial or prior measurement epoch. This paper describes how an arrangement of virtual lines, so-called grid lines (GL), offers a solution. A total station, measuring distances without a reflector, or a theodolite measurement system can be used to make the measurements. The GLs should intersect the object to be measured, as far as possible, at right angles and they can be arranged in such a way that each of them runs through one of the object points chosen for the initial measurements. Subsequently deformations of the object can be described along the GLs. The general idea behind this method is to track the virtual lines with the optical axis of a theodolite, until it aims at the points where the GLs intersect the surface. Tracking starts where the GLs intersected the surface of the object during the last measurement epoch. However, if the surface moved this point will be no longer an intersection point and the optical axis hits the surface at another point. Consequently there will be a separation of these two points, and if the theodolite starts tracking the GL, a distance function is obtained. This can be used to determine the new intersection point of the GL if that line is tracked until the value of the distance function is zero. The following sections describe how this process can be iteratively controlled by algorithms for an one-dimensional search space. The algorithms are based on the binary-search-, so-called parabola-, and regula-falsi method. Simulations and practical tests are used to evaluate the different search algorithms. The accuracy of the intersection points and the number of necessary iteration steps, describing the speed of the algorithms, are used as quality assessment parameters. Both quality characteristics depend on the truncation criteria: a distance and a length of an interval.

High accuracy 3D representation and monitoring of o bjects is an increasing field both in science and industrial applications. Up to now many tasks like monitoring of building deformations or displacements were solved by means of artificial targets on the objects of interest. Meanwhile mature optical 3D measurement t chniques are available. Such imagebased systems can perform their measurements even w ithout targeting. They use the texture on the object surface to find "interesting points" which can replace the artificial targets. Example for a monitoring task is the stability cont r l during the whole construction process of engineering buildings like bridges, high-rise build ings, dams, etc. This paper gives an overview of a new type of optical 3D measurement sy stem and its components. It uses learning-based object recognition techniques to sea rch for relevant areas to collect robust interest point candidates to be long-term tracked t o provide a deformation database. The task of deformation analysis is on one hand based on a t raditional geodetic deformation analysis process and on the other hand on a new developed pr ocedure called deformation assessment. The main goal of this development is to measure, an alyse and interpret object deformations by means of a highly automated process. We focus on key functional components, development stage and perspectives of the developed system.

High-precision online 3D-measurement systems can perform their measurements with and without targeting. Systems which are able to measure without artificial targets use the texture on the surface of the object to find 'interesting points'. However, well-trained 'measurement experts' are required to operate such a measurement system. In order to make such systems easy to use even for non-experts, we extend it by a knowledge-based component which supports the operator. We report on the architecture and functionality of the respective knowledge-based system, its development stage and the promising results obtained in experimentation.

Classical deformation analysis can benefit from methods based on tools of artificial intelligence. One advantage of these methods is that they can reproduce the human way of thinking, what means problem solving is done in a more intuitive way. This will be shown for three research fields: tunneling with the „New Austrian Tunneling Method“, monitoring of landslides and development of early warning systems.

In the past, high-precision online 3-D measuring required artificial targets defining the points on the objects to be monitored. For many tasks like monitoring of displacements of buildings, artificial targets are not desired. Todays image assisted theodolite systems can perform their measurements even without targeting. Such systems use the texture on the surface of the object to find "interesting points" which can replace the artificial targets. However, well-trained "measurement experts" are required to operate such a measurement system. In order to make such systems easy to use even for non-experts, it can be extended by an appropriate decision system which supports the operator. We report on the state of the art of such image assisted theodolite measurement systems and on the potential of future developments. Mainly, research work carried out at the Vienna University of Technology and Leica Geosystems (Heerbrugg) will be described here.

1. THE IDEA OF GRIDLINE-METHODS The need for contactless object detection and measurement makes special demands on geodetic measuring methods. The natural structure of the object’s surface or temporary targets like projected laser spots can be used to define the necessary targets. The measuring system for gridline-methods is theodolite based, using a pointer- and a video-theodolite working in a master-slave mode. The laser spot, which is projected by the master theodolite, has to be detected by the video-theodolite with an integrated CCD-array. The points representing the object are given by the intersections of the surface and virtual lines (fig.1) that are defined in a given co-ordinate frame. The general idea of the measuring method is to trace each of that gridlines until its point of intersection is found.