Multispectral airborne scanning devices gain increasing importance for example in the field of environmental monitoring. In Vienna, since a couple of years, a detailed information system about the status and changes of urban greenery is established and continuously updated in the course of the work program 'BiotopMonitoring Vienna' of the Austrian Health Institute (Österreichisches Bundesinstitut für Gesundheitswesen - ÖBIG) [Pillmann and Kellner, 2001]. These investigations are mainly based on aerial color infrared photographs, which were taken in different flight missions that were carried out by the German Aerospace Centre (Deutsches Zentrum für Luft- und Raumfahrt - DLR). In the flight mission Vienna 2000 realised on September 2000, a total of 24 multispectral airborne scanner images covering the whole area of Vienna were acquired. An integrated GPS/INS system was in use to provide direct observations for the outer orientation parameters of the scans.