From Airborne Digital Raw Data to Image Maps

Abstract

Recent airborne remote sensing applications show a tendency from an interpretation of single image strips to an evaluation of extended image maps for further usage in data fusion and GIS applications. Most of the problems during the mosaicking process are caused by geometric ortho-rectification errors, radiation variations across the single image strips and between adjacent image strips. The proposed procedure for generating ortho-rectified image maps consists of the following three steps. Within an image strip radiometric normalization is performed using an image-based empirical radiometric correction method, which accounts for sensor viewing angle effects. Individual strips are then ortho-rectified applying the direct georeferencing approach by using the onboard IGI CCNS/AEROcontrol-IIb system for the GPS/IMU integration and a digital elevation model. To remove the between-strip radiometric variations we propose to use a radiometric correction method, which is based on the information contained in the overlapping region of the image strips. The processing of data acquired by airborne multi-spectral scanner DAEDALUS AADS 1268 ATM show the effectiveness and potential of the proposed method especially for the thematic analysis applications.