We present an approach for automatic exterior orientation of aerial images which is based on the use of manhole covers as landmarks The approach includes two main procedures First a landmark extraction scheme which enables us to automatically detect and precisely localize many of the manhole covers visible in an image Second an automatic matching procedure which robustly and e ciently matches c...

This paper presented a click mechanism, which is inspired by a Dipteran insect, for use in flapping-wing micro aerial vehicle. The clicking mechanism is integrated in a thorax-like compliant mechanism, which buckles and consequently produces a large wing stroke when driven by an electric motor. The thorax-like compliant mechanism can store elastic energy in flexible hinges and is good for stori...

This paper describes a method for detecting and segmenting spherical features using the gradient angle transform. An analysis of the gradient angle for ideal spheres is presented, with a discussion of how this may be used to locate the boundaries of the sphere. The algorithms used by a program which detects and segments spherical features are then presented. The results of applying the program ...

We reconstruct past accretion rates of a salt marsh on the island of Sylt, Germany, using measurements of the radioisotopes Pb and Cs, as well as historical aerial photographs. Results from three cores indicate accretion rates varying between 1 and 16 mm year. Comparisons with tide gauge data show that high accretion rates during the 1980s and 1990s coincide with periods of increased storm acti...

This paper presents an approach for the automatic extraction of roads from digital aerial imagery. The approach makes use of several versions of the aerial image having different resolutions. Roads are modeled as a network of intersections and links between these intersections. For d ifferent so-called „global contexts" , i .e. , rural, forest, and urban area, the model describes relations betw...

(FACJ) system and its core tool, RealScape. RealScape automatically detects changes in the height and color of buildings based on three-dimensional analysis of aerial photographs. The three-dimensional analysis employs a pixel-by-pixel stereo processing method that calculates the height of each pixel in aerial photographs and thus enables precise difference detection between previous and curren...

Anders Hast, Uppsala University, Sweden, [email protected] Carlotta Capurro, Visual Dimension, Belgium Dries Nollet, Visual Dimension, Belgium Daniel Pletinckx, Visual Dimension, Belgium Benito Vilas Estevez, Universidad de Gales Trinity Saint David, Spain Miguel Carrero Pazos, Universidade de Santiago de Compostela, Spain Jose María Eguileta Franco, Sección de Arqueoloxía, Concello de Ouren...

Zigzag survey lines are frequently used in shipboard and aerial line transect surveys of animal populations. Analysis proceeds assuming that coverage probability through the survey region is uniform. We show that the two types of zigzag design that are in wide use do not generally have this property, and explore the degree of bias in abundance estimates that can be anticipated. We construct a z...