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This paper presents the research on influence of tie points located on corners and ridges of rooftops on the process of bundle adjustment. A set of 40 aerial photographs with 10 cm GSD from ISOK project was used in the research. The bundle adjustment was calculated three times with three different sets of tie points. First one with automatically measured tie points, second with automatic tie points together with manually measured point on rooftops corners and ridges, and third one only with manually collected points on rooftops corners and ridges. Then all different solutions were compared. The results prove that the use of tie points located on corners and ridges of rooftops does not lower the accuracy of bundle adjustment solution, which achieves value about 0.5 pixel. The conclusion might seem to be of low importance from the perspective of process of bundle adjustment, but it has an utmost practical consequence. In accordance with Polish law tie points with coordinates obtained in bundle adjustment process can be used as survey network in land surveying. Typically tie points measurements adopt FBM/ABM matching. In consequence detected tie points are almost impossible to identify in the field. Furthermore automatic measurement of points located on corners and ridges of rooftops is almost an impossibility. Nevertheless, providing tie points measured manually, or collected in automatic or semi-automatic manner with a new different algorithm, could significantly help in land survey. Especially with land survey of building outlines, where measurements could be then easily tied to nearby points.
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