Detection of Traffic Congestion in SAR Imagery

Detection of traffic congestion is an important issue both for the transportation research community and everyday life of the motorists. A new type of information is needed for a more efficient use of road networks. Remote sensing sensors installed on aircrafts or satellites enable data collection for various traffic applications over large areas, especially areas not covered with other, e.g. terrestrial sensors, or difficult accessible areas. Synthetic aperture radar (SAR) systems seem to be very promising due to their all-weather capability. We approach the traffic congestion detection problem with a two-channel SAR sensor flying in along-track (ATI) the motorway by combining various techniques: look processing, channel balancing, coherent change detection, e.g. displaced phase center array (DPCA), image processing and incorporation of a priori information such as traffic model and road network. The potential of the proposed method is demonstrated with airborne E-SAR data collected during several campaigns over highways in Germany. Method application for future tight formation of space satellites is discussed.