TRENDS IN DIGITAL PHOTOGRAMMETRY FROM AN INTERNATIONAL ENTERPRISE PERSPECTIVE

摘要

The internet hype for aerial and satellite images, kicked off by Google (Google Earth), Microsoft (Virtual Earth), and others, is giving the Photogrammetry, Remote Sensing, and GIS markets a tremendous exposure. Making the complete land coverage of Earth in the shortest time could only be achieved by satellite imagery. However, the growing demand for more and ubiquitous details in urban and developing zones can be achieved by aerial images of very high resolution. These internet providers made the idea of geo-referenced images very popular and extended the traditional geospatial market by opening the access to this data for different applications and thus created the now well-known geospatial web portals. As many of them, frequently and for cost reasons, make use of archived images or second-hand images. Professional users, driven by the needs of their businesses and engineering applications, are in demand for highly accurate and up to date geospatial information. So, the internet earth data providers are indirectly pushing the traditional markets, as well. These growing markets cause a very rapid development of image data acquisition systems and expanded geo-referencing applications. In this paper, the process of high resolution aerial images, capturing from the point of view of a service enterprise working in many different geographic regions, is discussed. Proven techniques in combination with highly automated workflows show process chain optimisation potentials in all known business aspects from planning, preparation, execution, to archiving of geospatial mapping projects. We put special emphasis on the economic use of available image sensor techniques and their integrations. Modern flight mission planning helps reduce flight execution time while optimising demanded along track and across track overlaps. 3D-modelling is one of the key elements of this advancement, and we discuss this aspect to some extent. Properties of the different digital large format camera systems have impact on the flight mission planning as well as the execution and thus require an adaptation from the traditional square-formatted pinhole camera model. How far new digital camera and scanner designs have impact on block geometry and accuracy are another aspect to be considered. Well known film development gets substituted with ground-processing, also called post-processing. The nature of the digital sensors deserve particular consideration when this technology is implemented in an internationally operating mapping company. Often times, international operations require additional logistics aspects to be taken care of, some of which will be presented in this paper. Customer's required ground resolution product ultimately drives a number of decisions and it will impact the planning phase or even before that such as consulting phase with the client who very often appears being uncertain what actually is needed for his particular application. Ultimately, archiving and retrieval of geo-spatial data is an important aspect to consider as well. For the safety of project execution, interim archiving steps should be integrated into the workflow. The resulting demand in storage and the capability to transfer large quantities of image data from one department to another department within an enterprise environment quickly put significant technical and economical demands on in-house infrastructure.