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Digital Photogrammetry Joins GIS - A Powerful Combination
Werner Mayr! and Wolfgang Reinhardt?
! Carl Zeiss, D-73446 Oberkochen, Germany
? Siemens Nixdorf Informationssysteme AG, D-81739 Munich, Germany
Commission IV
KEY WORDS: GIS, Photogrammetry, Automation, Digital, Matching
Abstract
This paper reports on the combination of Digital Photogrammetry and Geographic-Information-Systems. Traditionally
photogrammetry delivers three-dimensional world coordinates. GIS, however, administers in most cases two-dimensional world
coordinates and stores the elevation of an object as its attribute. The rapid progress in the technological field of digital
photogrammetry over the last few years has made available all classical, basic tasks of photogrammetry. These are
aerotriangulation, the generation of digital terrain models, orthoprojection, and, last but not least, three-dimensional data
acquisition in stereo plotters. All these functionalities are available in digital form, i.e. on the workstations which are the home of
GIS. As both technologies deal to a vast extent with coordinates, it appears natural to combine the two. In doing so DP contributes
its expertise in handling huge raster images and performing 3D-data capture, while GIS contributes its expertise in handling non-
topographic data and managing data bases. Integrating DP in GIS is mainly based on DP’s capability of forming automatic
measuring procedures. In this paper special focus is put on the usage of DP in GIS for the purposes of 3D-data acquisition, 3D-
visualisation. The potential 3D-manipulation of 2D-GIS-data by using a digital stereoplotter shall also be discussed in more detail.
1 Introduction In the following, an overview of today’s digital
photogrammetry is presented. There follows a chapter on GIS
Geographic information systems (GIS) are in widespread use and DP in which the special functions of DP for GIS are
in urban planning departments, and in traffic management, discussed. Finally, the concluding chapter summarizes this
telecommunications and utility companies among many others. paper and gives an outlook.
The ever increasing use of GIS also causes a significant
increase in requests for detailed information which has to be 2 Digital Photogrammetry
gathered and kept up-to-date. More powerful personal
computers and workstations allow for the processing of data Digital photogrammetry can now perform all basic
bases of ever increasing size. This again forces the requests to photogrammetric tasks. Besides the scanning of aerial images
GIS to increase. This acts like a spiral where GIS keeps which is a pre-requisite of DP, digital and automatic
constantly moving faster. The requests focus especially on the aerotriangulation, the automatic generation of DTMs, digital
administration of more detailed data, more precise reports, orthoprojection, and, last but not least, 3D data acquisition on
faster availability of results, and better visualisation tools for digital stereoplotters are now applied in production
presentations. environments. This availability of basic photogrammetric
functionality is considered as phase I of DP. The applications
GIS is not yet as much developed to administer true 3D-data are complete as can be seen in table 1 for the PHODIS family
as it is for 2D-data. For more detailed information the third of products for DP. An important design property of software
dimension, i.e. the elevation, has to be introduced as an based DP is the high modularity of single products and their
integral part of the geometric definition of an edge by using its components. This allows for a high ,recycling“ value which in
coordinates. In almost all GIS today this is achieved by turn eases the task of integrating DP in other systems, e.g. GIS.
assigning the elevation as an attribute to the object of interest.
As can be seen in the more recent literature (e.g. Kraus 1991, Product Photogrammetric Application
1995, Reinhardt 1991, Carosio 1995, Fritsch 1995, Kophstahl PHODIS SC photogrammetric scanning
1995) there is an ongoing discussion on the efficient treatment PHODIS AT automated digital aerial triangulation
of true 3D-data in a true 3D-GIS. It is, however, without doubt PHODIS ST digital stereoplotting
that photogrammetry is ideally suited to do topographic 3D PHODIS TS automatic DTM generation
data capture. PHODIS OP digital orthoprojection
So far 3D data has been captured at analytical stereo plotters HEM onopouins
which were equipped with data acquisition systems tailored for
photogrammetry. Since the technology of Digital
Photogrammetry (DP ) constantly gains in relevance it appears
n joi i ; Its of 3
DT T CIS SEES PON qe vital UE E SCAI is the name of the scanner module in PHODIS. It has the
models (DTM) have been it en Ga cenain extent. This capability to handle uncut original roll film. It is integrated into
paper focusses on some of the potential DP-data-acquisition — € PHODIS SC scanning system. The availability of the roll
Table 1: PHODIS products and applications overview
capabilities and their integration in GIS. The D-system film autowinder is an important step towards automating the
PHODIS of Carl Zeiss is used as an example for this A/D conversion of large amounts of analog imagery (Mehlo
integration 1995, Roth 1996). Roll films can be automatically digitized
553
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996