AUTOMATIC DEM AND ORTHOPHOTO 
GENERATION ON ANALYTICAL 
STEREOPLOTTERS 
Hans Schoch, R&D Manager, ADAM Technology, Enterprise Unit 1, Technology Park, Bentley, Western Australia 6102 
Peter M. Roberts, Product Manager, ADAM Technology, Enterprise Unit 1, Technology Park, Bentley, Western Australia 6102 
M.E. Goble-Garratt, Sales & Marketing Manager, ADAM Technology, Enterprise Unit 1, Technology Park, Bentley, Western 
Australia 6102 
Commission IV, Working Group 4 
KEYWORDS: Orthoimage, Correlation, Digital, Rectification, CCD, DEM/DTM 
ABSTRACT 
Soft copy photogrammetry offers two main advantages over analytical stereoplotters, the automatic generation of DEMs (digital 
elevation models) and Orthophotos. In a production environment soft copy systems have significant disadvantages, the need to scan 
and store all the images, the need for more highly trained operators, the reduced ability to digitise exact detail only to name a few. 
To keep the amount of disk storage space required for the scanned data at a workable level, companies are forced to scan their 
images as coarsely as possible. This reduces the ability to digitise very small features on a soft copy system. The pixels can be too 
large, making it impossible for the operator to identify very small features. 
ADAM Technology believe that by adding CCD cameras to their analytical stereoplotter, most automatic features offered on soft 
copy systems can be offered on an analytical stereoplotter, hence combining the best of both worlds. 
There is an increasing demand for orthophotos and orthophoto maps world-wide. The automatic DEM and Orthophoto generation 
project based on ADAM Technology's analytical stereoplotter, the PROMAP system, will offer a cost effective solution to meet 
these demands. This technology will combine the accuracy and ease of use of the analytical stereoplotters with the automatic 
features offered by soft copy systems. 
KURZFASSUNG 
Digitale Photogrammetrische Systeme bieten 2 Hauptvorteile gegenüber analytisches Auswertegerüten, die beinahe automatische 
Erzeugung von digialen Orthophotots und die automatische Erzeugung von digitalen Gelándemodellen. Im productiven Gebrauch 
hingegen weisen diese Systeme schwerwiegende Nachteile auf. Der Speicher Bedarf fuer die Bilder in digitaler Form ist enorm 
und der Aufwand fuer die Ausbildung des Benutzers ist erheblich hóher. Um den Speicher Aufwand fuer die digitalen Bilder in 
einem vernünftigen Rahmen zu halten, sind Firmen gezwungen die Flugbilder mit einer relativ groben Auflósung zu scannen. 
Durch den resultiereneden Verlust von Detail Information wird es dem Benutzer verunmóglicht die feinsten Einzelheiten noch zu 
vermessen. E 
Eine alternative Lósung wird hier vorgestellt. CCD-Kameras sind in einem analytischen Auswertegerát eingebaut und erlauben die 
meisten Operationen die auf digitalen Photogrammetrischen Arbeitsplátzen möglich sind. Digitale Geländemodelle und 
Orthophotos koennen kostengünstig und weitgehend automatisch erstellt werden. Das von ADAM Technology hergestellte 
analytische Auswertegerüt, das PROMAP System, ausgeruested mit CCD-Kameras und entsprechender Software bieted dem 
Anwender die beste Kombination von einfacher Handhabung, genaueste Vermessung von Einzelheiten, und zusátzlich die 
automatische Funktionen für Orthophotos und digitalen Gelándemodell Erstellung. 
Overview 
ADAM Technology is developing a new range of products for ^ stereoplotter and a frame grabber mounted in the host PC. The 
Automatic DEM and Orthophoto Generation which will be CCD cameras view the same portion of the model as the 
released as options for the successful ADAM PROMAP operator, however a smaller field of view. The frame grabber 
System analytical stereoplotter. This paper describes the ^ converts the video images from the cameras into digital images 
development of these products at the time of writing. which can be analysed by computer software. 
The ADAM Automatic DEM and Orthophoto Generation For orthophoto production the working image area is acquired 
options consist of a software package, two CCD cameras with in colour from one side only and the colour image corrected for 
lenses mounted in the ADAM PROMAP analytical height displacement. The DEM required for this step can be 
756 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996 
  
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