The Application of GF-1 Imagery to Detect Ships on the Yangtze River

Various satellite data are currently used to detect ships on the sea surface. However, no study on the use of Gaofen-1 (GF-1) data to monitor ships on the surface of inland rivers has been reported. Therefore, we proposed a method to extract inland river-surface ships from GF-1 imagery. The Normalized Differential Water Index was calculated to enhance the contrast between water and non-water areas after the preprocessing procedure. The multi-resolution segmentation method and object-oriented classification rule sets were used to detect the ships in the image. Results show that most of the ships, whose length-to-width ratio ranges from 3.0 to 7.2, could be identified correctly regardless of their size. The results also indicate that detecting ships on inland rivers using GF-1 imagery is feasible.