Simulation of High Resolution Satellite Imagery from Multispectral Airborne Scanner Imagery for Accuracy Assessment of Fusion Algorithms

For the years 1997 to 2000 it is expected that a number of new satellites will be launched into orbit by private companies which are speciied to deliver panchromatic imagery of the earth surface with a spatial resolution as ne as 1 m. In contrast to the panchromatic band, the spectrally resolved bands will have a four times coarser ground resolution. Therefore, image fusion algorithms will certainly be employed in order to producèsharpened' color imagery. The new satellites have the potential of stimulating and expanding the remote sensing market for image products at a resolution around one meter. In order to prepare for this era we have examined image fusion algorithms using already available airborne imagery. This paper tests fusion algorithms on imagery which was simulated using multispectral images of an airborne scanner (DAEDALUS ATM) with an average resolution of 1 m. The main advantage of a simulation of satellite images is the possibility to immediately check the deviation between the original 1 m imagery and the fused (1 m + 4 m) multispectral image. Thus, various fusion algorithms can be tested with regard to their accuracy concerning e. g. land cover classiication or change detection. The spectral accuracy of the fused imagery depends strongly on the spatial resolution and scene content. Therefore, accuracy assessments from e. g. SPOT + LANDSAT TM-fusion can certainly not simply be extrapolated down to 1 m imagery. We nd that the spectral accuracy of the simulated fused imagery indeed varies with diierent fusion algorithms. Even though the spectral accuracy of the fused imagery turns out to be limited, we nd consistent results of land cover classiications. For the years 1997 to 2000 it is expected that a number of new satellites will be launched into orbit by private companies (Gupta 1995, Doyle 1996) which are speciied to deliver imagery of the earth surface of a spatial resolution as ne as 1 m. This ne a resolution has so far been the privilege of airborne rather than spaceborne overhead imagery { at least as far as the civilian community and multispectral (in contrast to panchromatic) imagery is concerned. Airborne image ights have a longstanding importance for cadastre, local planning and environmental monitoring (e.g. the health status of public trees in the city of Hamburg is monitored on aerial Color In-frared (CIR) photographs). So far the necessary image ights are conducted by private enterprises on particular …