mobile mapping project - Zoller+Fröhlich

Z+F PROFILER 6007 duoData acquisitionDue to the two laser scanningsystems, the overall systemperformance is doubled, allowingthe carrier vehicle to travel withhigh velocities on the railway net,still maintaining high scanresolutions and point densities.Both laser scanning systems aresynchronized to be able toachieve a data acquisition rateof 2 x 508,000 pixels per secondwith 2,048 points per capturedprofile.The horizontal and vertical resolutions between two consecutive crosssectionsdepend on the driven speed:Speed v[km/h]/[mp/h]Rotations persecond[rps]Max. no. ofpoints percross-sectionHorizontalresolution 1)[mm]50/31 500 2048 27,8 10,720/12 500 2048 11,2 10,710/6 500 2048 5,6 10,75/3 500 2048 2,8 10,71) distance between two consecutive measured cross-sectionsVertical resolution at adistance of 3.5 m tothe scanner-center 2)[mm]2) distance between two consecutive measured points within one cross-sectionon a surface which is perpendicular to the measuring direction of the laser beamSynchronization and absolutepositioningFor kinematic laser scanning thecarrier-vehicle's driven trajectoryneeds to be determined, usingexternal navigation sensors. Withthis information the capturedtwo-dimensional measurementscan be processed into georeferenced,absolute three-dimensionalCartesian coordinates.Since those external navigationsensors are not defined in acommon standard, they are notintegrated in the Z+F PROFILER6007 duo.Therefore suitable interfaces forexternal synchronisation signalsare provided.Sensor data as well as scan dataare recorded with unique identifiers(time stamps or distancestamps) to be able to synchronizeboth data streams.4