GEOSCAN Search Results: Fastlink


TitleDSM generation and evaluation from QuickBird stereo imagery with 3D physical modelling
AuthorToutin, T
SourceInternational Journal of Remote Sensing vol. 25, no. 22, 2004 p. 5181-5193,
Alt SeriesEarth Sciences Sector, Contribution Series 2004243
PublisherInforma UK Limited
Mediapaper; on-line; digital
File formatpdf
Subjectsdigital terrain modelling
Released2010 11 26
AbstractA digital terrain model (DTM) extracted from QuickBird in-track stereo images using a three-dimensional (3D) multisensor physical model developed at the Canada Centre for Remote Sensing, Natural Resources Canada was evaluated. Firstly, the stereo photogrammetric bundle adjustment was set-up with about 10 accurate ground control points and 1-2 m errors in the three axes were obtained over 48 independent checkpoints. The DTM was then generated using an area-based multi-scale image matching method and 3D semi-automatic editing tools and then compared to lidar elevation data with 0.2-m accuracy. An elevation error with 68% confidence level (LE68) of 6.4 m was achieved over the full area. Since the DTM is in fact a digital surface model where the height, or a part, of land covers (trees, houses) is included, the accuracy is depending on the land cover types. Using 3D visual classification of the stereo QuickBird images, different classes (deciduous, conifer, mixed and sparse forests, residential areas, bare soils and lakes) were generated to take into account the height of the surfaces (natural and human-made) in the accuracy evaluation. LE68 values of 3.4 m to 6.7 m were thus obtained depending on the land cover types with biases representative of the surface heights. On the other hand, LE68 values of 0.5 m and 1.3 m with no bias were obtained for lakes and bare soils respectively. These last results are more representative of the real stereo QuickBird potential for DTM and 5-m contour lines generation, compliant with the highest topographic standard. Since the images were acquired in wintertime and the lidar data in summertime, better results could be thus expected when using stereo images acquired in summertime, mainly in deciduous forests to integrate the full canopy height into the DSM.

Date modified: