Aerial triangulation of digital Aerial imagery using hybrid features

Exterior Orientation Parameters (EOPs) of imaging sensors are demanded in different mapping tasks such as orthophoto and DEM generation, 3D extraction and object reconstruction. Bundle adjustment is one of the useful methods to determine the EOPs of all the images in a block with relatively low number of control points. As finding the corresponding points in is difficult especially in automatic matching procedures, and depending on the ground topography, some points might be hidden or be in occluded areas in images, in recent years, lots of investigations in the field of using straight line segments and other feature primitives in aerial triangulation are provided by different researchers. In this paper, the standard point-based collinearity equations together with the modified line-based collinearity equations proposed by Schenk are implemented and evaluated on a small block of six overlapped (60% side overlap and 25% strip overlap) digital aerial images of DiMac sensor. In this method, the optimal parametric representations of object straight lines are used to model the relationship between image space and object space. Parametric representation of features in object space allows the specification of any point on the feature. The main advantage of block adjustment using linear features is its high reliability and its capability to cope with the problem of occluded areas and is more reliability for automation. The results of block adjustment using points and lines, confirm the capabilities of the utilized method.