RIASSUNTO
There is frost in Bohai bay every winter due to the geographical latitude and the cold air coming down from the north. The annual winter sea ice in the Bohai Bay has become a natural disaster which affects the port manipulation, shipping transportation severely. At present, the remote sensing technology has been very mature in sea ice monitoring. As one of the most important multispectral data source in China, HJ satellite data is commonly used in every aspect of marine, resources and environment. In this paper, we takes the HJ-1A/B CCD data as the data source to monitor the sea ice happened on Bohai bay west coast along Tianjin City in early 2010. By a standard technology method composed of data preprocessing, unsupervised classification, object-oriented classification, post-classification etc., we get the sea ice extraction results rapidly and accurately. By analyzing and contrasting the different period's results, we monitor and trend the sea ice growth which is accordant with the actual situation. The remote sensing image of HJ-1A/B data with high time-space resolution can provide powerful technical support for the analysis of the real-time sea ice monitoring and it's meaningful for port construction and shipping transportation.