Taking the advantage of sun glitter(SG)observed from high-resolution satellites Gaofen-1(GF-1)and Gaofen-6(GF-6),a new method named Shield and Vortex 1-2(SAV1-2)for extracting spatial texture information from sun glit...Taking the advantage of sun glitter(SG)observed from high-resolution satellites Gaofen-1(GF-1)and Gaofen-6(GF-6),a new method named Shield and Vortex 1-2(SAV1-2)for extracting spatial texture information from sun glitter was established.Sea surface texture detail information around Diaoyu Dao and its affiliated islands was extracted using SAV1-2.Meanwhile,the dynamic characteristics of the water environment were analyzed by combining the water color,temperature and dynamic data.The results show the following information.(1)Stable westward shield effect and eastward Karman vortex streets,extracted from SG,appear upstream(westward)and downstream(eastward)of the Diaoyu Dao and its affiliated islands respectively.(2)The dominant direction of the Kuroshio Current in the Diaoyu Dao and its affiliated islands area is east,the Diaoyu Dao and its affiliated islands interacting with Kuroshio,inducing western shield and eastern shelter and wake.Furthermore,wave intervals of the shield in front of the island range from hundreds to thousands of metres,and extend wider than the island itself.(3)Combining with high-resolution sea surface temperature(SST)and chlorophyll a(Chl a)concentration,the directional changes of water color elements are mutually supported and proved with the stable shield(wave packet)effect in the west and vortex street effect in the east.The change of SST upstream of the island(western shield area)is not significant,the temperature in the downstream shelter area decreases slightly,and the SST in the downstream wake area shows a general trend of obvious decrease.The wake area is dominated by Karman vortex streets in shape,supplementing by vortices.The concentration of Chl a in the west shield of island is as low as that in downstream shelter area,while it increases significantly in the downstream wake area with shape in eddy or ribbon.(4)The SAV methods of extracting sea surface texture detail using SG can be widely used in different sea areas and water quality.This paper can provide reference for the protection and development of Diaoyu Dao and its affiliated islands and its surrounding waters.It is suggested that some kind of current buffer,such as marine wind farm,should be established in the western waters of Diaoyu Dao and its affiliated islands to protect the islands,and marine pasture should be developed in the downstream of eastern waters of Diaoyu Dao and its affiliated islands.展开更多
High resolution optical satellite imageries containing the sun glitter,similar to synthetic aperture radar（SAR） imageries,are useful in identifying and mapping of bottom topography in shallow waters.The errors in th...High resolution optical satellite imageries containing the sun glitter,similar to synthetic aperture radar（SAR） imageries,are useful in identifying and mapping of bottom topography in shallow waters.The errors in the previous studies are corrected,and a method for mapping submarine bottom topography is developed using the sun glitter satellite imagery.The method is established on the basis of empirical description of a sand wave using an equation with two unknowns named r and k.In order to determine r and k,a ＂trial and error＂ approach is introduced and testified by a case study on the Taiwan Banks using an ASTER imagery.The results show that the inversed water depths match well with the sounding water depths.The agreement between the inversed results and the in situ measurements is about 78% by comparing 371 points.Moreover,this method has the advantage in keeping the original appearance of a sand wave,especially in positions around the sand wave crest.The fine agreement indicates that the imaging model is flexible and the approach developed is feasible.展开更多
The brightness reversal of submarine sand waves appearing in the small satellite constellation for environ- ment and disaster monitoring and forecasting （＂HJ- 1A/B＂） CCD sun glitter images can affect the observati...The brightness reversal of submarine sand waves appearing in the small satellite constellation for environ- ment and disaster monitoring and forecasting （＂HJ- 1A/B＂） CCD sun glitter images can affect the observation and depth inversion of sand wave topography. The simulations of the normalized sun glitter radiance on the submarine sand waves confirm that the reversal would happen at a specific sensor viewing angle, defined as the critical angle. The difference between the calculated critical angle position and the reversal position in the image is about 1＇, which is excellent in agreement. Both the simulation and actual image show that sand wave crests would be indistinct at the reversal position, which may cause problems when using these sun glitter images to analyze spatial characteristics and migration of sand waves. When using the sun glitter image to obtain the depth inversion, one should take the advantage of image properties of sand waves and choose the location in between the reversal position and the brightest position. It is also necessary to pay attention to the brightness reversal when using ＂HI-1A/B＂ CCD images to analyze other oceanic features, such as internal waves, oil slicks, eddies, and ship wakes.展开更多
We are familiar with the idea that the elements from which we are made were created in stars, but where does gold come from, to pick on a heavier element？ Thanks to the optical detection of GW170817, reported here fr...We are familiar with the idea that the elements from which we are made were created in stars, but where does gold come from, to pick on a heavier element？ Thanks to the optical detection of GW170817, reported here from the AST3-2 telescope [1], and at other southern telescopes, a day after its detection by LIGO, we are now closer to answering that question with a fascinating story of binary stellar evolution.展开更多
The growth of a global leader in the artificial gem business Mention the name Wuzhou and few people outside of China will know where, or even what you are talking about. The city, in south China’s Guangxi Zhuang Auto...The growth of a global leader in the artificial gem business Mention the name Wuzhou and few people outside of China will know where, or even what you are talking about. The city, in south China’s Guangxi Zhuang Autonomous Region, is little known beyond the borders of the world’s展开更多
Chinese ice and snow art debuts in Finland Reindeer and panda stand side by side in front of a wall of bamboo paintings with flute and the cry of birds echoing nearby. Standing at the entrance of ICIUM-Wonderworld of ...Chinese ice and snow art debuts in Finland Reindeer and panda stand side by side in front of a wall of bamboo paintings with flute and the cry of birds echoing nearby. Standing at the entrance of ICIUM-Wonderworld of Ice theme park, they greet visitors in a traditional Chinese way in the Arctic twilight.展开更多
基金The Science Foundation of Donghai Laboratory under contract No.DH-2022KF01010the Zhejiang Key Science and Technology Project under contract No.2020C02004+1 种基金the Basic Public Welfare Research Program of Zhejiang Province under contract No.LGF21D010004the Research on Group Ideological and Political Subject Teaching Model of Ocean Remote Sensing under contract No.132.
文摘Taking the advantage of sun glitter(SG)observed from high-resolution satellites Gaofen-1(GF-1)and Gaofen-6(GF-6),a new method named Shield and Vortex 1-2(SAV1-2)for extracting spatial texture information from sun glitter was established.Sea surface texture detail information around Diaoyu Dao and its affiliated islands was extracted using SAV1-2.Meanwhile,the dynamic characteristics of the water environment were analyzed by combining the water color,temperature and dynamic data.The results show the following information.(1)Stable westward shield effect and eastward Karman vortex streets,extracted from SG,appear upstream(westward)and downstream(eastward)of the Diaoyu Dao and its affiliated islands respectively.(2)The dominant direction of the Kuroshio Current in the Diaoyu Dao and its affiliated islands area is east,the Diaoyu Dao and its affiliated islands interacting with Kuroshio,inducing western shield and eastern shelter and wake.Furthermore,wave intervals of the shield in front of the island range from hundreds to thousands of metres,and extend wider than the island itself.(3)Combining with high-resolution sea surface temperature(SST)and chlorophyll a(Chl a)concentration,the directional changes of water color elements are mutually supported and proved with the stable shield(wave packet)effect in the west and vortex street effect in the east.The change of SST upstream of the island(western shield area)is not significant,the temperature in the downstream shelter area decreases slightly,and the SST in the downstream wake area shows a general trend of obvious decrease.The wake area is dominated by Karman vortex streets in shape,supplementing by vortices.The concentration of Chl a in the west shield of island is as low as that in downstream shelter area,while it increases significantly in the downstream wake area with shape in eddy or ribbon.(4)The SAV methods of extracting sea surface texture detail using SG can be widely used in different sea areas and water quality.This paper can provide reference for the protection and development of Diaoyu Dao and its affiliated islands and its surrounding waters.It is suggested that some kind of current buffer,such as marine wind farm,should be established in the western waters of Diaoyu Dao and its affiliated islands to protect the islands,and marine pasture should be developed in the downstream of eastern waters of Diaoyu Dao and its affiliated islands.
基金The National Natural Science Foundation of China under contract Nos 40476023 and 40876031
文摘High resolution optical satellite imageries containing the sun glitter,similar to synthetic aperture radar（SAR） imageries,are useful in identifying and mapping of bottom topography in shallow waters.The errors in the previous studies are corrected,and a method for mapping submarine bottom topography is developed using the sun glitter satellite imagery.The method is established on the basis of empirical description of a sand wave using an equation with two unknowns named r and k.In order to determine r and k,a ＂trial and error＂ approach is introduced and testified by a case study on the Taiwan Banks using an ASTER imagery.The results show that the inversed water depths match well with the sounding water depths.The agreement between the inversed results and the in situ measurements is about 78% by comparing 371 points.Moreover,this method has the advantage in keeping the original appearance of a sand wave,especially in positions around the sand wave crest.The fine agreement indicates that the imaging model is flexible and the approach developed is feasible.
基金The Marine Scientific Public Welfare Research Special Foundation under contract No.201105001the Key Laboratory of Ocean Dynamic Processed and Satellite Oceanography under contract No.SOED1006
文摘The brightness reversal of submarine sand waves appearing in the small satellite constellation for environ- ment and disaster monitoring and forecasting （＂HJ- 1A/B＂） CCD sun glitter images can affect the observation and depth inversion of sand wave topography. The simulations of the normalized sun glitter radiance on the submarine sand waves confirm that the reversal would happen at a specific sensor viewing angle, defined as the critical angle. The difference between the calculated critical angle position and the reversal position in the image is about 1＇, which is excellent in agreement. Both the simulation and actual image show that sand wave crests would be indistinct at the reversal position, which may cause problems when using these sun glitter images to analyze spatial characteristics and migration of sand waves. When using the sun glitter image to obtain the depth inversion, one should take the advantage of image properties of sand waves and choose the location in between the reversal position and the brightest position. It is also necessary to pay attention to the brightness reversal when using ＂HI-1A/B＂ CCD images to analyze other oceanic features, such as internal waves, oil slicks, eddies, and ship wakes.
文摘We are familiar with the idea that the elements from which we are made were created in stars, but where does gold come from, to pick on a heavier element？ Thanks to the optical detection of GW170817, reported here from the AST3-2 telescope [1], and at other southern telescopes, a day after its detection by LIGO, we are now closer to answering that question with a fascinating story of binary stellar evolution.
文摘The growth of a global leader in the artificial gem business Mention the name Wuzhou and few people outside of China will know where, or even what you are talking about. The city, in south China’s Guangxi Zhuang Autonomous Region, is little known beyond the borders of the world’s
文摘Chinese ice and snow art debuts in Finland Reindeer and panda stand side by side in front of a wall of bamboo paintings with flute and the cry of birds echoing nearby. Standing at the entrance of ICIUM-Wonderworld of Ice theme park, they greet visitors in a traditional Chinese way in the Arctic twilight.
