摘要

A hybrid method of edge detection of radar images and classification of fused infrared and microwave SAR images is developed for automatic detection of the main road network in a dense urban area. Fusion of the infrared and microwave SAR images effectively reduces the noise in the edge detection and also effectively removes possible confusion with non-road objects, i. e. linearly featured rivers in the classification. Possible road candidates are further processed using the morphological thinning algorithm. Road linking and extension are carried out hierarchically according to the characteristics of the main roads as well as their connections. Finally, the main road network is successfully established from the SAR image. The approach is effective and accurate in detecting road segments and linking without complicated mathematic models, e. g. the Snake or Genetic Algorithms. As an example, using the ERS-2 SAR image data, automatic detection of the main road network in Shanghai Pudong area is presented.