The methods and models used are quite simple, and the modelled objects lack detail. Yu et al. [8] studied the use of laser scanners and video cameras in creating detailed models of the road surface, and their models seem geometrically quite accurate, down to small cracks in the road surface. Vandetanib cancer Zhao and Shibasaki [5] used line www.selleckchem.com/products/Calcitriol-(Rocaltrol).html cameras and laser scanners to produce textured planar surfaces.Many methods using stationary terrestrial scanning have been proposed Inhibitors,Modulators,Libraries Inhibitors,Modulators,Libraries (e.g. [9-12]). In some applications, the methods can be directly applied to mobile mapping, but in some cases, the data produced by mobile mapping are too different from the data provided by stationary scanning. Two main differences between stationary and mobile scanning are the evenness of the data and the perspective.
In mobile mapping, the point cloud is evenly distributed along the driving direction, and the viewing direction to the target remains approximately constant.In this paper, we propose an automatic retrieval method Inhibitors,Modulators,Libraries to model Inhibitors,Modulators,Libraries a road, consisting of kerbstones and road surface along with the paintings, including zebra crossings and roadside parking spaces, based on a dense point cloud produced by vehicle-based laser scanning. The curbstones and markings on the road are segmented by applying image-processing algorithms to the intensity and height images, and the pavement is modelled as a triangulated irregular network based on the point cloud. A comparison with previous work shows that Goulette et al.
[7] modelled the road surface as a flat plane as opposed to our TIN, which better describes the irregularities in the surface.
Yu et al. [8] used a densified point cloud from video cameras, whereas Inhibitors,Modulators,Libraries we only use a single laser scanner with a profile spacing of c. 20-50 cm. The previously mentioned methods focused on finding the geometry either as simple planes or as a highly detailed Inhibitors,Modulators,Libraries model, whereas our study concentrates more on classifying and modelling the road surface.1.3. FGI RoamerThe MMS data were collected with the FGI Roamer mobile mapping system developed Inhibitors,Modulators,Libraries at Inhibitors,Modulators,Libraries the Finnish Geodetic Institute. The Roamer consists of a Faro LS 880 laser scanner with a measurement frequency of 120 kHz and a NovAtel HG1700 SPAN58 INS system.
With slightly modified hardware for the standard FARO LS, it provides so-called tunnel mode, or profile measurements, synchronized with external positioning and data logging systems.
This information is needed to derive the position and attitude information for each 3D point produced by the laser scanner. The Carfilzomib mirror rotation frequency, or scan rate of the scanner on the Roamer can be set to 3-30 Hz, thus giving a vertical angular resolution Anacetrapib of 0.0096-0.096 sellekchem selleck products degrees (0.17-1.7 mrad), respectively. Corresponding point spacing at a typical scanning range of 15 metres in road mapping is thus 2.5-25 mm in the scanning plane. [13]1.4. Modelling processThe modelling process consisted of several steps.