Izdelava digitalnega modela površja in ortopodob iz stereo posnetkov ikonos, zajetih v istem preletu

Digital surface model and ortho-images generation from ikonos in-track stereo images

Author(s):

Aleš Marsetič, Krištof Oštir

Abstract:

The paper describes the generation of a digital surface model (DSM) and orthoimages from panchromatic and multispectral Ikonos stereopairs. It assesses the suitability of the images for vegetation height mapping of a large area and the applicability of the results for various spatial analyses. The processing steps involved stereo bundle adjustment with various sets of ground control points, digital surface model extraction, orthoimage generation and evaluation of the results. Although both multispectral and panchromatic stereoimages were processed, the DSM was generated only for the panchromatic stereopair due to its higher resolution. For evaluation purposes it was compared to very accurate lidar elevation data. The analysis revealed an overall vertical difference between the models of 8.2 m, where only one third of the differences are below 3 m. The results were worse in steep areas with high vegetation and regions with shadows caused by hills or clouds. Better results can be obtained with previous manual or automatic editing of the automatically extracted model. On the other side, orthoimages that were also produced are very accurate – the evaluation showed results with horizontal RMSE errors below 1.5 pixels for both stereopairs when compared to aerial orthophotos.

Keywords:

Ikonos stereo satellite images, digital surface model, stereoscopy, ortho-images, evaluation

DOI: 10.15292/geodetski-vestnik.2010.03.433-449

Citation:

Aleš Marsetič, Krištof Oštir (2010). Izdelava digitalnega modela površja in ortopodob iz stereo posnetkov ikonos, zajetih v istem preletu. | Digital surface model and ortho-images generation from ikonos in-track stereo images. Geodetski vestnik, 54 (3), 433-449. DOI: 10.15292/geodetski-vestnik.2010.03.433-449