
0ae91b7769951e23dff210fea72e81b7.ppt
- Количество слайдов: 1
Use of GIS Methodology for Online Urban Traffic Monitoring German Aerospace Center Aim enhancement of accuracy of derivation of traffic flow parameters of an operational airborne traffic monitoring system and installation of a traffic GIS Institute of Transport Research M. Hetscher S. Lehmann I. Ernst A. Lippok M. Ruhé System Overview Camera external information sources GPS/INS Data Downlink Image Recording Ground Station Georeferencing Map Matching Preprocessing/ Vehicle Detection Traffic Data Extraction Prognosis Processing Chain 200 Hz 3 x Gyro DQ x, y, z DV x, y, z Results and Improvement Results 200 Hz GPS/INS Integration • 61 % of vehicles correctly counted • less 20 % false counted cars • improvement to 75 % by exclusion of parking cars Kalman Filter 3 x Accel 1 Hz Lat, Long, Altitude GPS 1 Hz remote • Position Lat, Long, Altitude • Attitude Roll, Pitch, Heading • Time Improvements Kinematic Dif. GPS DGPS Service Provider Simulation/ Compression IMU Data Ware House Database Server • integration of navigation data into image header for synchronisation of data streams correction • matching accuracy • separation of traffic active area • extension of a-priori knowledge • improvement of digital mask • data and sensor fusion • spatio temporal data analysis 06. 05. 2003 16: 24: 54 [-0. 7800 0. 6800 268. 0900] [52. 51452 13. 35138 719. 10] 06. 05. 2003 16: 24: 54 [-0. 7800 0. 6800 268. 0900] [52. 51452 13. 35137 719. 10] 06. 05. 2003 16: 24: 54 [-0. 7800 0. 6800 268. 0900] [52. 51452 13. 35136 719. 09] Different Cameras for Image recording with synchronous record of GPS/INS-Data Parameter IR-Camera Vis Camera Detector. Type MCT, cooled at 77°K IR 18 MK III CCD Number of pixels 768 ´ 500 1980 ´ 1079 Field of view 15, 28° x 10, 20° 50° Rad. dynamics/ Spectrum 8 Bit / 8 – 14 µm 12 Bit / 450 -700 nm Frame rate 25 Hz 0. 2 Hz GSD flight height 3500 ft 0. 5 m 0. 3 m Swath width 380 m Satellite image projection to digital map 594 m Absolute Accuracy Position Roll, Pitch Heading GPS DGPS 4 - 6 m 0. 015 deg 0. 08 deg 0. 5 – 2 m 0. 015 deg 0. 05 deg • system calibration, analysis of position- und attitude data • test of all street segments of a sufficient area around the recorded region regarding their intersection with the image and determination of observed edge intervals. Separation of Vegetation direct Referencing of Image Data to digital Map (NAVTEQ) • determination of probable street width from map attributes (NAVTEQ: type, speed category, rough lane number, direction) and road construction regulations, generation of virtual search region with overlapping polygons • broad variety of appearance due to different conditions led to contour search algorithms in edge images, dependent from actual parameter search for characteristic contours and size for vehicle hypothesis. Pixel values are used as additional information Application to online System • for derivation of velocity vectors determination of virtual car position from last image and projection into actual image. Differences to real position in actual image give value and direction of velocities Image Processing for Traffic Data Extraction • car list per image and section ID: • traffic data per image and section ID DLR - IVF Rutherfordstraße 2 D-12489 Berlin Tel: (+49)30 -67055 -646 Fax: (+49)30 -67055 -202 Mail: Matthias. Hetscher@dlr. de Ines. Ernst@dlr. de [(x, y), v, size class] to do • temporal analysis for seasonal variation • urban image classification • texture and content analysis • data fusion [str. ID, (t 0, t 1), [rho 1, v 1], [rho 2, v 2], [rho 3, v 3]] weighted average for several images • traffic data per section ID: • traffic data per NAVTEQ-edge Density, average speed determination [str. ID, %seen, [rho 1, v 1], [rho 2, v 2], [rho 3, v 3]] weighted average for several section IDs [timestamp, edge. ID, %seen, [rho 1, v 1], [rho 2, v 2], [rho 3, v 3]] Traffic Data Aggregation • Prognosis and closure of time gaps by simulation Generation of Traffic Information and Recommandations Traffic GIS for offline applications • database for heterogenous sources • improvement for traffic simulations • traffic scenario validation • spatio temporal data analysis (isochrones, travel times, cachment areas) • visualisation of socioeconomic analysis • mobility research
0ae91b7769951e23dff210fea72e81b7.ppt