| In recent years,most of the Arctic sea area have been navigable in summer as sea ice in the Arctic has receded in large areas.As the closest maritime transport route connecting China and Europe,the Northeast Passage(NEP)not only effectively shortens the navigation distance and shipping time,reduces shipping costs,but also avoids interference on traditional routes such as strait dilemmas and piracy issues.To sum up,the NEP have great potential for development.However,the navigation environment of the NEP is complicated,and sea ice and harsh sea conditions on the waterway can threaten the navigation safety of ships,even cause major loss of life and property.Therefore,the acquisition and analysis of sea ice conditions,sea surface wind field,sea wave and other parameters in the NEP are of great importance to the navigation safety of ships.Satellite remote sensing is an important technical means for obtaining sea ice and marine dynamic environmental parameters in the Arctic.Based on multisource satellite remote sensing data,this paper carried out a study on the safety of navigation in NEP.The main contents and relevant conclusions are as follows:1.Satellite remote sensing data is applied to analyze and study the sea ice and sea wind field in the NEP.Firstly,sea ice concentration products retrieved by microwave radiometer are adopted to analyze ice conditions and navigation conditions in significant areas of the NEP from 2010 to 2019,and the navigation window with respect to the corresponding sea areas are acquired.On this basis,this paper analyzes the changes of sea ice conditions in key sea areas where the navigation route could be affected,and preliminarily explains the reasons for the changes of sea ice generation and depletion in this area.Secondly,the wind field data retrieved by scatterometer from 1999 to 2018 is applied to analyze the historical summer wind fields in crucial areas of the NEP,and the once-in-a-decade,once-in-50-year and once-in-a-century wind speeds of the NEP from July to September were calculated by using the extreme value theory.The results show that the summer wind field in the NEP is stable,with an average wind speed of about 6m/s,and the extreme wind speed changes smoothly.2.In this paper,the sea ice detection,sea surface wind inversion,effective wave height and wave direction spectrum inversion algorithms based on Synthetic Aperture Radar(SAR)data are briefly introduced,and the accuracy of sea ice detection algorithm is analyzed.IMS sea ice extent data and AMSR2 sea ice concentration data are used as verification data to compare with the sea ice detection results of Sentinel-1 SAR images from July to September 2018.The results show that the matching accuracy between the sea ice detection result and IMS is 85.01%,while the matching accuracy between the sea ice detection result and AMSR2 is 88.69%.It is found that discrete ice floes in summer is the main factor affecting the matching accuracy in further discussion.3.Based on C#,MATLAB language programming and Visual Studio 2010 development environment,this paper integrated the space-borne SAR Arctic sea ice and ocean dynamic parameter extraction algorithm,designed and constructed the “Space-borne SAR Arctic sea ice and ocean dynamic information processing system”.On the one hand,this system realized the detection of sea ice coverage and retrieval of wind field from Sentinel-1 SAR and GF-3 SAR data.On the other hand,the retrieval of effective wave height and wave direction spectrum from Sentinel-1 SAR data are also initilized.4.This paper designed a set of quasi-operational navigation guarantee scheme for the NEP,and applied the scheme to the Arctic navigation guarantee of COSCO Special Transportation Co.,Ltd successfully.During the two years of cooperation with COSCO SHIPPING,a total of7 batches of sailing guarantees have been provided for its commercial ships sailing in the Arctic,which has achieved good social and economic benefits. |
