共查询到20条相似文献，搜索用时 28 毫秒
1.
Dome A is the highest ice feature in the Antarctica,up to now,little is known about surface topography at Dome A.The first Chinese ITASE expedition was carried out from Zhongshan station to Dome A during the 1996/1997 austral summer. During the 2004/2005 austral summer,the traverse was extended to the summit of Dome A which is 1228 km from Zhongshan Station by 21st Chinese National Antarctic Research Expedition (CHINARE).The real-time kinematic (RTK) GPS survey was carried out in the summit of Dome A dur... 相似文献
2.
LIU Jiying WEN Jiahong WANG Yafeng WANG Weili Beata M CATHSO Kenneth CJEZEK 《中国地理科学(英文版)》2007,17(2):160-165
Dome A, the highest dome of East Antarctic Ice Sheet, is being an area focused by international Antarctic community after Chinese Antarctic Expedition finally reached there in 2005, and with the ongoing International Polar Year (IPY) during August 2007. In this paper two data processing methods are used together to generate two 100-m cell size digital elevation models (DEMs) of the Dome A region (Dome A-DEM) by using Cokriging method to interpolate the ICESat GLAS data, with Ihde-DEM as a constraint. It provides fundamental data to glaciological and geophysical investigation in this area. The Dome A-DEM was applied to determining the ice-sheet surface elevations and coordinates of the south and north summits, defining boundaries of basins and ice flowlines, deducing subglacial topography, and mapping surface slope and aspect in Dome A region. The DEM shows there are two (north and south) summits in Dome A region. The coordinate and the surface elevation of the highest point (the north summit) are 80°21′29.86″S, 77°21′50.29″E and 4092.71±1.43m, respectively. The ice thickness and sub-ice bedrock elevation at north summit are 2420m and 1672m, respectively. Dome A region contains four drainage basins that meet together near the south summit. Ice flowlines, slope and aspect in detail are also derived using the DEM. 相似文献
3.
基于黑暗像元和大气透过率的遥感图像校正 总被引：1，自引：0，他引：1
介绍了黑暗像元法光学遥感图像大气校正的基本原理,并根据典型大气条件考虑了光谱的大气透过率分布,设计了一定大气条件下的自动光学遥感图像校正算法.通过对具体的图像模式进行的校正处理效果比较,在图像本身比较模糊的情况下,校正效果较好,而对于图像本身比较清晰的情况下,校正效果不明显,但色彩得到改进并更接近原始色彩,计算表明,在光学遥感图像校正要求不是特别高或者大气条件比较均匀的情况下,是一种仅靠图像信息本身即可进行大气校正的简单方便的方法,具有一定的实用价值. 相似文献
4.
The heights of automatic weather station (AWS) sensors over the Antarctic ice sheet are nominal and change with snow accumulation or ablation. Therefore, the measured data may not be used directly. In this study, we analyzed the impact of snow accumulation on AWS observations using continuous measurements from three AWS that were deployed on the traverse route from the Zhongshan Station to Dome A over East Antarctica. We then corrected the measured air temperature to account for changes in the sensor height relative to the snow surface to improve the authenticity and representativeness of the observation data from the AWS. The results show that (i) the annual mean snow accumulations at Dome A, Eagle and LGB69 were approximately 0.11 m, 0.30 m and 0.49 m, respectively, and the corresponding annual mean air temperature differences between the corrected and measured values at 1 m in height were 0.34℃, 0.29℃ and 0.35℃; (ii) the impact on air temperature from accumulation decreases with height from the surface; (iii) the air temperature difference between the corrected and measured values was not directly proportional to the snow accumulation but was related to the seasonal air temperature variations and the intensity of the local surface inversion; and (iv) the averaged corrected air temperature was higher than the measured values except during the summer when there were days without temperature inversion. The magnitude of the temperature difference between the corrected and measured was mainly determined by snow accumulation and the intensity of the local surface inversion. 相似文献
5.
为满足涉密计算机用户对外网图文信息的实时接收、查看和监控等需求,设计并实现一种用于单向传输设备的屏幕图像实时传输系统.该系统采用镜像驱动方式快速、高效地获取屏幕图像;设计适合单向传输设备的屏幕图像实时传输协议用于在无反馈的情况下数据包能够实时传输到接收端;并通过发送相邻2张图像的异或数据减少系统所占带宽;以及每发送一定异或图像数据后发送一张完整图像的方法,解决传输过程中的丢包而导致接收图像错乱的问题.通过测试表明,该系统在低CPU使用率,低带宽占用率的情况下能够提供良好的实时图像传输服务,满足单向传输设备中屏幕图像实时传输的要求. 相似文献
6.
A preliminary application GIS in glaciological research along the traverse route from Zhongshan Station to Dome A, Antarctica 总被引：1，自引：0，他引：1
1 IntroductionGeographicalinformationsystem (GIS)isanefficientwayandimportanttechniquetomanage,displayandanalyzeAntarcticspatialdata.GIScanbeusedtomakeandre newmapproductsquickly ,evaluateenvironment,supportlogisticmanagementandfieldoperation,providechancetoextractnewknowledge,andtopromoteinformationex changeamongnationsunderthedemandoftheMadridProtocol(AADC 2 0 0 1 ;MAGIC1 998;1 999) .WorkingGroupofGeodesyandGeographicInformation (WG GGI)ofScientificCommitteeonAntarcticResearch (… 相似文献
7.
利用Bedmap2数据与中国第29次南极科学考察期间获取的冰雷达数据,在中山站至Dome A断面的Gamburtsev山脉地区首次构建11.3 km×11.5 km南极局部冰盖三维模型。着重介绍三维模型建立过程中的数据处理,其中冰雷达数据采集首次采用中国自主研发的冰雷达系统。详细阐述了冰雷达数据的处理流程,包括数据预处理、常规图像修正技术以及冰下地形获取,得到冰下基岩埋深和冰盖内部等时层埋深,插值得到100 m分辨率的冰下基岩DEM（海拔1 729 m~2 718 m）和等时层DEM（海拔2 601 m~2 950 m）,利用南极Bedmap2冰表面栅格影像得到100 m分辨率的冰盖表面DEM（海拔3 679 m~3 745 m）。结合冰盖内外部数据处理结果,构建包含冰盖表面、冰盖内部等时层和冰下基岩地形特征的三维模型,并对模型进行检验,对冰盖内外部地形特征进行初步分析。 相似文献
8.
以多路径误差和电离层延迟为评价指标,利用TEQC软件和QCVIEW软件对南极埃默里冰架、内陆冰盖、纳拉峡海湾、拉斯曼丘陵的实测GPS数据以及部分IGS站点的数据进行了数据质量分析,得到结论： 1)在同一站点上,L2上的多路径误差总比L1上的多路径误差要大;2)在南极不同环境下的多路径误差不同;3)纬度和太阳活动剧烈程度是影响南极地区GPS数据电离层延迟大小的两个重要因素。 相似文献
9.
目前,物理模型的单幅图像去雾已成为图像去雾算法研究的重点。在分析了暗原色先验知识的单幅图像去雾算法基础上,针对暗原色先验去雾算法时间复杂度大的缺点,比较了目前已有的暗原色先验改进去雾算法,提出了一种新的暗原色先验单幅图像去雾改进算法。通过引入快速、各向同性的低通高斯滤波器,实现对透射率图的平滑均匀,以代替暗原色去雾方法中精妙但时间复杂度高的软抠图算法;对于图像中图层交界处,提出了以区域中值滤波方法进行修正的算法,以及满足自适应要求的全局大气光求解详细算法。实验结果表明,结合了以上3点改进的快速去雾算法在保证图像去雾效果的同时,能大幅度提高暗原色去雾算法的速度,适用于对工程上的图像、视频实时去雾。 相似文献
10.
《山地科学学报》2021,(10)
There are numerous studies on polar amplification and its influence on mid-latitude weather and climate. However, assessments on whether polar amplification occurs in Antarctica are rarely conducted. Based on the latest atmospheric reanalysis of ERA5 produced by European Centre for Medium-Range Weather Forecasts(ECMWF), we have defined the Antarctic amplification index, and calculated the trend of annual and seasonal Surface Air Temperature(SAT) mean during 1979-2019 for Antarctic Ice Sheet(AIS) and the trend mean of different meridional sectors of Antarctic sub regions including East Antarctic Ice Sheet(EAIS), West Antarctic Ice Sheet(WAIS) and Antarctic Peninsula(AP). Antarctic amplification shows regional differences and seasonal variations. Antarctica shows a slight warming with the largest magnitude in AP. The temperature anomalies indicate the least fluctuations in austral summer, and the more fluctuations in winter and spring. In austral summer, the warming trend domains EAIS and WAIS, while the cooling trend appears over AP. The zonal mean in Southern Hemisphere maintains a warming trend in the low latitudes, and fluctuates greatly in the middle and high latitudes. The strongest Antarctic amplification phenomenon occurs in spring, with the amplification index of 1.20. For AP, the amplification occurs in austral autumn, and the amplification index is 2.16. At South Pole and the surrounding regions, SAT for land only fluctuates largely and shows different trends in different seasons. The mechanism of Antarctic amplification is unclear till now, and its research suffers from the limitation of measured data. This suggests that future research needs progress in comprehensive ground observation network, remote sensing data accumulation, and high-resolution climate modeling with better representation of both atmospheric and cryospheric processes in Antarctica. 相似文献
11.
T Svenφe 《极地研究(英文版)》2002,13(1)
1 ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅＡｕｒｏｒａｌＳｔａｔｉｏｎｉｎＡｄｖｅｎｔｄａｌｅｎｗａｓｂｕｉｌｔｉｎ 1 978ａｎｄｈａｓｗｏｒｋｅｄａｓａｎｏｐｔｉｃａｌｓｉｔｅｆｏｒｇｒｏｕｎｄ -ｂａｓｅｄｏｂｓｅｒｖａｔｉｏｎｓｏｆｔｈｅｄａｙｓｉｄｅａｎｄｎｉｇｈｔｓｉｄｅａｕｒｏｒａｉｎｔｈｅｐｏｌａｒｃａｐ .Ｆｉｇｕｒｅ 1ｓｈｏｗｓａｐｈｏｔｏｇｒａｐｈｏｆｔｈｅｓｔａｔｉｏｎｔｏｇｅｔｈｅｒｗｉｔｈａｔｙｐｉｃａｌｓｔｏｒｍｔｙｐｅａｕｒｏｒａ(Ｓｉｍｍｏｎｓｅｔａｌ.1 996) .Ｔｈｅｓｔａｔｉｏ… 相似文献
12.
The Antarctic and Arctic are sensitive to global climate change; therefore, they are key regions of global climate change research. This paper, the progress in scientific investigations and research regarding the atmosphere in the polar regions over the last 30 years by Chinese scientists is summarized. Primary understanding of the relationship between the polar regions and global change, especially, the variations in time and space in the Antarctic and Arctic regions with respect to climate change is indicated. Operational weather forecasts for investigation of the polar regions have also been established. Moreover, changes in sea ice and their impact on the atmosphere of polar regions have been diagnosed and simulated. Parameterization of the atmospheric boundary layer of different underlying layers and changes in the atmospheric ozone in the polar region has also been experimented. Overall, there has been great progress in studies of the possible impact of changes in the atmospheric environment of polar regions on circulation in East Asia and the climate of China. 相似文献
13.
气溶胶光学厚度作为描述气溶胶光学特性的重要参数之一, 被广泛应用于空气质量监测及辐射传输模型的大气订正等研究中。卫星遥感可快速反演获取大范围气溶胶信息, 但其产品通常因云覆盖或暗目标算法等原因而存在空间覆盖率较低的问题, 且产品时相受限于卫星过境时间。水平能见度作为描述气溶胶光学特性的另一重要参数, 由分布广泛的气象台站一日8 次固定时间多次发布。建立水平能见度与气溶胶光学厚度的转换关系, 可实现对卫星反演气溶胶光学厚度的有益补充。本文利用2001-2009 年的MODIS气溶胶光学厚度产品与中国华东地区71 个气象台站的水平能见度数据, 对描述两者转换关系的Peterson 模型进行区域优化。采用分区域高斯曲线拟合的方法, 对影响转换精度的主要参数气溶胶标高随时间变化规律开展研究和模拟。利用2010 年数据对优化模型进行精度及区域适用性验证。结果表明, 优化后模型的气溶胶光学厚度估算均方根误差为0.31, 低于原模型误差;精度基本上与单站点优化模型一致, 但在实用性方面优于单站点优化模型。 相似文献
14.
CBERS-1CCD相机飞行绝对辐射标定试验地面同步测量与场地辐射特性分析 总被引：4，自引：1，他引：3
中国对地观测遥感卫星辐射校正场(即敦煌场)位于中国敦煌市西戈壁沙漠的西北角。整个敦煌场地面比较均匀、平坦,面积为30×40km2;测试区(标定区)面积为400×400m2,位于场区的中心位置。2000年8月底至9月初,中国资源卫星应用中心联合安徽光机所在敦煌场地进行了一次CBERS-1CCD传感器飞行绝对辐射标定试验。地表反射率和大气光学特性地面同步测量结果显示:敦煌场地的地面均匀性好,各个通道反射率的变化系数(即相对变化百分比)均小于3%。在可见光、近红外光谱范围内,地面光谱反射率随波长增加逐步增大,例如,在485nm波长处的地面反射率值约为0.18,在830nm波长处的反射率值约为0.26。大气光学特性测量结果显示:0.55μm波长处的大气总光学厚度(≈0.34)和气溶胶光学厚度(≈0.26)相对较小,大气水汽含量也较小。 相似文献
15.
《中国海洋湖沼学报》2017,(5)
Defects in protective-coating systems on steel surfaces are inevitable in practical engineering applications.A composite coating system,including a primer,middle coat and topcoat,were used to protect carbon steel from corrosion in a marine environment.Two environmental additives,glass fi bers and thiourea,were applied in the middle coat to modify the coating system.The long-term corrosion durability and self-healing ability of the scratched coating system were evaluated by multiple methods.Results of the electrochemical technologies indicated that the coating system that contained 0.5 wt.%fi bers and 0.5 wt.%thiourea presented good corrosion protection and self-healing for carbon steel when immersed in 3.5%Na Cl for 120 d.Evolution of localized corrosion factors with time,as obtained from the current distribution showed that fi bers combined with thiourea could inhibit the occurrence of local corrosion in scratched coating systems and retarded the corrosion development signifi cantly.Surface characterization suggested that adequate thiourea could be absorbed uniformly on fi bers for a long time to play an important role in protecting the carbon steel.Finally,schematic models were established to demonstrate the action of fi bers and thiourea on the exposed surface of the carbon steel and the scratched coating system in the entire deterioration process. 相似文献
16.
1 Introduction Nowadaysglobalclimatechangehasbeenanimportantissueintheworld.Antarctic areaisjustthekeyandsensitiveregion,fromwhichscientistsaretryingtheirbesttofind theomenofglobalclimatechange.Andfortherevolvingglobalatmosphere,PolarRegions arecoldsource.TheoceanicandatmosphericconditionofPolarRegionsisimportantto globalatmosphericcirculationandclimatechange.Antarcticareaisoneofthecoldsources ofglobalearth atmospheresystem,whileequatorialareaisitsmainheatsource(seeZhou andLuetal.1996).… 相似文献
17.
Antarctic krill (Euphasia superba Dana) is a key organism of the Antarctic marine ecosystem and a potential fishery resoure. Its ecology was the major biological
project in the First Chinese Antarctic Expedition (1985). Acoustic observations and IKMT tows were madecin waters north and
west of Antarctic Peninsula. Environmental factors were also observed. Analyses of the population structure, i.e. the sex
percentage distribution and other data obtained show that among the 3,640 individuals of determinable sex, only 38.1% were
males and that the larger the body length the smaller the percentage of males, for example, male percentage dropped to 8.3%
for size group >55 mm. The population's relations to environmental factors are also discussed.
Contribution No. 1711 from the Institute of Oceanology, Academia Sinica. 相似文献
18.
Toshitaka Suzuki Yoshinori Iizuka Teruo Furukawa Kenichi Matsuoka Kokichi Kamiyama Okitsugu Watanabe 《极地研究(英文版)》2003,14(1)
1 IntroductionAntarcticicesheetisaburialgroundforatmosphericdeposition .Sincethereiscon tinuousinteractionbetweentheicesheetandtheatmosphere,variousatmosphericsub stancesareinjectedtotheicesheetsequentiallyintimeandspace.Therefore,verticalanalysesoftheicesheetprovideuswithinformationaboutpastclimaticchange (Delmas1 992 ;LegrandandMayewski 1 997)andhorizontalanalysesoftheicesheetprovideuswithknowledgeregardinglong rangetransportofairbornematerials (Kamiyamaetal.1 989;KreutzandMayewski 1 999)… 相似文献
19.
A Method for Retrieving Water-leaving Radiance from Landsat TM Image in Taihu Lake, East China 总被引：1，自引：0，他引：1
WANG Deyu FENG Xuezhi MA Ronghua KANG Guoding 《中国地理科学(英文版)》2007,17(4):364-369
The visible and infrared bands of Landsat Thematic Mapper (TM) can be used for inland water studies. A method of retrieving water-leaving radiance from TM image over Taihu Lake in Jiangsu Province of China was investigated in this article. To estimate water-leaving radiance, atmospheric correction was performed in three visible bands of 485nm, 560nm and 660nm. Rayleigh scattering was computed precisely, and the aerosol contribution was estimated by adopting the clear-water-pixels approach. The clear waters were identified by using the Landsat TM middle-infrared band (2.1μm), and the water-leaving radiance of clear water pixels in the green band was estimated by using field data. Aerosol scattering at green band was derived for six points, and interpolated to match the TM image. Assuming the atmospheric correction coefficient was 1.0, the aerosol scattering image at blue and red bands were derived. Based on a simplified atmospheric radiation transfer model, the water-leaving radiance for three visible bands was retrieved. The water-leaving radiance was normalized to make it comparable with that estimated from other remotely sensed data acquired at different times, and under different atmospheric conditions. Additionally, remotely sensed reflectance of water was computed. To evaluate the atmospheric correction method presented in this article, the correlation was analyzed between the corrected remotely sensed data and the measured water parameters based on the retrieval model. The results show that the atmospheric correction method based on the image itself is more effective for the retrieval of water parameters from Landsat TM data than 6S (Second Simulation of the Satellite Signal in the Solar Spectrum) code based on standard atmospheric and aerosol models. 相似文献
20.
为使原本用于人工地震测深野外数据采集的PDS型地震仪能够适用于超密集流动台阵野外观测,设计了一种基于Apollo2微控制器的具备GNSS校钟同步和仪器工作参数动态设置功能的外置即插即用式自动控制装置。经室内测试运行和野外比对测试实验,该装置运行稳定可靠,能满足野外超密集台阵长期连续工作的需要。 相似文献