@incollection {jaehne2007d,
	title = {Data analysis},
	year = {2007},
	pages = {1437--1491},
	publisher = {Springer},
	chapter = {25},
	abstract = {From the beginning of science, visual observation has played a major role. At that time, the only way to document the results of an experiment was by verbal description and manual drawings. The next major step was the invention of photography more than one and a half centuries ago, which enabled experimental results to be documented objectively. In experimental fluid mechanics, flow visualization techniques gave direct insight into complex flows, but it was very difficult and time consuming to extract quantitative measurements from photographs and films. Nowadays, we are in the middle of a second revolution sparked by the rapid progress in both photonics and computer technology. Sensitive solid-state cameras are available that acquire digital image data, and standard personal computers and workstations have become powerful enough to process these data. These technologies are now available to any scientist or engineer. As a consequence, image processing has expanded and continues to expand rapidly from a few specialized applications into a standard scientific tool. This chapter gives a brief presentation of some of the most important general image processing techniques that are required to process image data in experimental fluid mechanics. The second section (Sect. 25.2) deals with motion analysis. The most important methods are introduced and classified according to the fundamental principles, assumptions and approximations upon which they are based.},
	doi = {10.1007/978-3-540-30299-5_25},
	author = {Bernd J{\"a}hne and Michael Klar and Markus Jehle},
	editor = {C. Tropea and J. Foss and A. Yarin}
}
@phdthesis {klar2005,
	title = {Design of an endoscopic 3D Particle-Tracking Velocimetry system and its application in flow measurements within a gravel layer},
	year = {2005},
	publisher = {IWR, Fakult{\"a}t f{\"u}r Physik und Astronomie, Univ.\ Heidelberg},
	abstract = {In this thesis a novel method for 3-D flow measurements within a permeable gravel layer is developed. Two fiberoptic endoscopes are used in a stereoscopic arrangement to acquire image sequences of the flow field within a single gravel pore. The images are processed by a 3-D Particle-Tracking Velocimetry (3-D PTV) algorithm, which yields the three-dimensional reconstruction of Lagrangian particle trajectories. The underlying image processing algorithms are significantly enhanced and adapted to the special conditions of endoscopic imagery. This includes methods for image preprocessing, robust camera calibration, image segmentation and particle-tracking. After a performance and accuracy analysis, the measurement technique is applied in extensive systematic investigations of the flow within a gravel layer in an experimental flume at the Federal Waterways Engineering and Research Institute in Karlsruhe. In addition to measurements of the pore flow within three gravel pores, an extended experimental setup enables the simultaneous observation of the near-bed 3-D flow field in the turbulent open-channel flow above the gravel layer and of grain motions in a sand layer beneath the gravel layer. The interaction of the free surface flow and the pore flow can be analyzed for the first time with a high temporal and spatial resolution. The experiments are part of a research project initiated by an international cooperation called Filter and Erosion Research Club (FERC). The longterm goal of this project is to quantify the influence of turbulent velocity and pressure fluctuations on the bed stability of waterways. The obtained experimental data provide new insight into the damping behaviour of a gravel bed and can be used for comparison with numerical, analytical and phenomenological models.},
	url = {http://www.ub.uni-heidelberg.de/archiv/5961},
	author = {Michael Klar}
}
@conference {klar2004a,
	title = {Analysis of subsurface gravel layer flow caused by turbulent open-channel flow using 3D PTV and pressure sensor techniques},
	booktitle = {BAW-Workshop Soil and Bed Stability - Interaction Effects between Geotechnics and Hydraulic Engineering},
	year = {2004},
	author = {Michael Klar and Markus Jehle and Bernd J{\"a}hne and Detert, M. and Jirka G. H.}
}
@conference {jehle2004,
	title = {Bewegungsdetektion und Geschwindigkeitsanalyse in Bildfolgen zur Untersuchung von Sedimentverlagerungen},
	booktitle = {Mitteilungen des Instituts f{\"u}r Grundbau und Bodenmechanik},
	volume = {77},
	year = {2004},
	pages = {371-392},
	author = {Markus Jehle and Michael Klar and H.-J. K{\"o}hler and Heibaum, M.}
}
@conference {detert2004,
	title = {Pressure fluctuations within subsurface gravel bed caused by turbulent open-channel flow},
	booktitle = {Proc. of River Flow 2004},
	year = {2004},
	pages = {695-701},
	publisher = {A. A. Balkema Publishers},
	organization = {A. A. Balkema Publishers},
	author = {Detert, M. and G. H. Jirka and Markus Jehle and Michael Klar and Bernd J{\"a}hne and H.-J. K{\"o}hler and Wenka, T.}
}
@conference {klar2004c,
	title = {Simultaneous 3D PTV and micro-pressure sensor equipment for flow analysis in subsurface gravel layer},
	booktitle = {Proc. of River Flow 2004},
	year = {2004},
	pages = {703--712},
	publisher = {A. A. Balkema Publishers},
	organization = {A. A. Balkema Publishers},
	author = {Michael Klar and Markus Jehle and Detert, M. and G. H. Jirka and Bernd J{\"a}hne and H.-J. K{\"o}hler and Wenka, T.}
}
@incollection {klar2002,
	title = {3D-Str{\"o}mungsmessung in Kiesporen},
	year = {2002},
	pages = {247--250},
	publisher = {Wichmann},
	url = {http://d-nb.info/96618503X},
	author = {Michael Klar and P. Stybalkowski and Hagen Spies and Bernd J{\"a}hne},
	editor = {Thomas Luhmann}
}
@conference {klar2002a,
	title = {A miniaturized 3-D particle-tracking velocimetry system to measure the pore flow within a gravel layer},
	booktitle = {Proc. 11th Int. Symp. Applications of Laser Techniques to Fluid Mechanics},
	year = {2002},
	pages = {2.3},
	url = {http://in3.dem.ist.utl.pt/lxlaser2002/papers.asp},
	author = {Michael Klar and P. Stybalkowski and Hagen Spies and Bernd J{\"a}hne}
}
@mastersthesis {klar2001,
	title = {3D Particle-Tracking Velocimetry applied to Turbulent Open-Channel Flow over a Gravel Layer},
	year = {2001},
	school = {IWR, Fakult{\"a}t f{\"u}r Physik und Astronomie, Univ.\ Heidelberg},
	author = {Michael Klar}
}
