利用多代卫星测高数据计算中国近海及邻域重力异常   总被引：1，自引：0，他引：1  

刘善伟  李家军  万剑华  杨俊钢 《海洋科学》2015,39(12):130-134

为提高海洋重力场数据的精度和空间分辨率,联合Jason-1/2、T/P、Envisat、ERS-1/2、Geosat等多代卫星测高数据计算中国近海及邻域(0°~42°N,100°~140°E)2′×2′重力异常。对卫星测高数据分别进行共线处理和自交叉点平差,并以T/P卫星测高数据为基准进行多星数据联合平差,有效削弱了卫星测高数据的时变影响和不协调性;利用逆Vening-Meinesz公式计算重力异常,与船测重力相比,均方根误差为5.4 mgal。结果表明,通过引入高精度的卫星测高数据,结合多项平差处理手段,提高了海洋重力异常的计算精度。  相似文献   

The SARAL/AltiKa Altimetry Satellite Mission     

Jacques Verron  Pierre Sengenes  Juliette Lambin  Jocelyne Noubel  Nathalie Steunou  Amandine Guillot 《Marine Geodesy》2015,38(3):2-21

The India-France SARAL/AltiKa mission is the first Ka-band altimetric mission dedi-cated to oceanography. The mission objectives are primarily the observation of the oceanic mesoscales but also include coastal oceanography, global and regional sea level monitoring, data assimilation, and operational oceanography. Secondary objectives include ice sheet and inland waters monitoring. One year after launch, the results widely confirm the nominal expectations in terms of accuracy, data quality and data availability in general.

Today's performances are compliant with specifications with an overall observed performance for the Sea Surface Height RMS of 3.4 cm to be compared to a 4 cm requirement. Some scientific examples are provided that illustrate some salient features of today's SARAL/AltiKa data with regard to standard altimetry: data availability, data accuracy at the mesoscales, data usefulness in costal area, over ice sheet, and for inland waters.  相似文献   

First Calibration Results for the SARAL/AltiKa Altimetric Mission Using the Gavdos Permanent Facilities     

Stelios P. Mertikas  Antonis Daskalakis  Ilias N. Tziavos  George Vergos  Xenofon Fratzis  Achilleas Tripolitsiotis 《Marine Geodesy》2015,38(3):249-259

This work presents the first calibration results for the SARAL/AltiKa altimetric mission using the Gavdos permanent calibration facilities. The results cover one year of altimetric observations from April 2013 to March 2014 and include 11 calibration values for the altimeter bias. The reference ascending orbit No. 571 of SARAL/AltiKa has been used for this altimeter assessment. This satellite pass is coming from south and nears Gavdos, where it finally passes through its west coastal tip, only 6 km off the main calibration location. The selected calibration regions in the south sea of Gavdos range from about 8 km to 20 km south off the point of closest approach. Several reference surfaces have been chosen for this altimeter evaluation based on gravimetric, but detailed regional geoid, as well as combination of it with other altimetric models.

Based on these observations and the gravimetric geoid model, the altimeter bias for the SARAL/AltiKa is determined as mean value of ?46mm ±10mm, and a median of ?42 mm ±10 mm, using GDR-T data at 40 Hz rate. A preliminary cross-over analysis of the sea surface heights at a location south of Gavdos showed that SARAL/AltiKa measure less than Jason-2 by 4.6 cm. These bias values are consistent with those provided by Corsica, Harvest, and Karavatti Cal/Val sites. The wet troposphere and the ionosphere delay values of satellite altimetric measurements are also compared against in-situ observations (?5 mm difference in wet troposphere and almost the same for the ionosphere) determined by a local array of permanent GNSS receivers, and meteorological sensors.  相似文献   

IMPROVING THE EFFECT OF GREENING ON HEAT ISLAND IN URBAN RESIDENTIAL DISTRICTS BASED ON REMOTE SENSING AND GIS ANALYSIS     

周红妹  葛伟强  杨何群  刘洁  杨燕丽 《热带气象学报(英文版)》2015,21(3):303-310

Analyzing the thermal distribution on plane conditions objectively is difficult due to lack of enough meteorological observation stations within urban residential areas. In this paper satellite observations synchronous or quasi-synchronous with ground observations are adopted, and a teleconnection model is built between the satellite spectral and surface temperature for quantitative retrieval of temperature. Furthermore, by combining the satellite data with other multiple factors, a GIS comprehensive analysis model and a functional evaluation method for urban residential districts are established, which are used to study the relation between the air temperature and media characteristics on ground as well as the greening cooling effect in recent years in Shanghai. The results show that the air temperature in greened urban residential districts is generally lower than the average temperature and much less than the highest one. In general, the average air temperature in the greened area is at most 1.19℃ lower than the maximum temperature in the districts, which is 0.67℃ and 0.55℃ lower than that of the highest for buildings and roads respectively. The temperature is inversely proportional with greening fraction but is directly proportional with the ratio of roads and buildings. The higher the greening fraction in internal residential districts, the lower the temperature, and the higher the ratio of road and building is, the higher the temperature.  相似文献   

基于TRMM资料的高原涡与西南涡引发强降水的对比研究   总被引：4，自引：0，他引：4  

蒋璐君  李国平  王兴涛 《大气科学》2015,39(2):249-259

利用TRMM(Tropical Rainfall Measuring Mission)卫星探测结果结合NCEP(National Centers for Environmental Prediction)再分析资料, 对2007年7月17日四川、重庆地区的一次西南涡强降水系统和2008年7月21日四川东部的东移高原涡强降水系统的三维结构特征、雨顶高度以及降水廓线特征进行对比分析研究。结果表明:(1)两次降水过程均是发生在西南—东北向的水汽辐合带中, 且降水云群均位于低涡的东南方。(2)两次强降水在水平结构上均表现为由一个主降水雨带和多个零散降水云团组成, 高原涡强降水过程比西南涡强降水的降水强度和范围都要大。降水雷达探测到的两个中尺度降水系统均以降水范围大、强度弱的层云降水为主, 但对流性降水对总降水量的贡献较大, 其中西南涡降水中对流降水所占比例比高原涡的大, 对总降水率的贡献也大。(3)垂直结构上:两次强降水的雨顶高度均是随地表雨强的增加而增加, 且最大雨顶高度接近16 km, 但西南涡强降水中的雨顶高度比高原涡更高, 说明西南涡降水过程中对流旺盛程度强于高原涡。(4)两次强降水中雨滴碰并增长过程以及凝结潜热的释放主要集中在8 km以下, 但8 km以上西南涡降水变化大于高原涡, 且前者在8~12 km高度层的降水量对总降水量贡献百分比大于后者。  相似文献   

时空窗口对HY-2有效波高产品检验影响模拟研究     

陈春涛  李军  翟万林  赵屹立  朱建华 《海洋技术学报》2015,34(5):31-36

时空窗口的选择是卫星高度计有效波高产品检验的主要影响因素。采用Monte Carlo(MC)数学模拟的方法 ,研究了时空窗口对HY-2高度计有效波高检验的影响,并采用现场浮标测量数据验证了MC模拟的可靠性。MC模拟结果表明,采用浮标测量数据对HY-2高度计有效波高检验时,必须分海况选取对应的最优空间窗口进行,并给出不同海况下的最优的时空窗口。对于高海况需采用小的空间窗口,在1 m,2 m,3 m,4 m有效波高的海况下,其理想的时空窗口为0 min,117 km,30 km,18 km和13 km。  相似文献   

频率可切换的矩形缝隙环频率选择表面     

廖翔宇  李亚鹏  杜国宏 《成都信息工程学院学报》2015,30(1):18-21

基于金属屏上周期排列的缝隙单元结构的通带特性,提出矩形缝隙环(Rectangular Slot Ring,RSR)加载短路线的单元结构实现频率可调频率选择表面(Frequency Selective Surface,FSS)。谐振缝隙单元开路与短路时相对应的谐振频率分别为13 GHz和15 GHz。RSR-FSS选用Rogers RO4003介质作为基板,按照12×12的方阵进行周期排列,利用全波电磁仿真软件CST对其进行了电磁传输特性仿真。最终,通过实验验证了该频率选择表面在Ku波段通过连通和断开短路线可以进行频率的切换。  相似文献   

资源一号02C卫星数据在北京岩溶水资源勘查评价工程中的应用   总被引：2，自引：0，他引：2  

程洋  童立强  郭兆成  莫源富  纪轶群 《国土资源遥感》2015,(2):183-189

以资源一号02C(ZY1-02C)卫星数据为数据源,以GIS为数据处理平台,以遥感地质理论和水文地质理论为指导,将遥感技术应用于北京岩溶水资源勘查评价工程中。通过水文地质遥感解译和综合分析,优选了一处新的供水水源地,建立了适用于北方岩溶区的含水岩组和泉点的遥感解译标志,提出了基于GIS的水文地质分析方法,扩展了国产资源卫星数据的应用领域。  相似文献   

利用先验重力场模型对GOCE卫星重力梯度观测值进行校准分析   总被引：1，自引：1，他引：0  

徐新禹  赵永奇  魏辉  吴汤婷 《测绘学报》2015,44(11):1196-1201

GOCE卫星任务搭载了高灵敏度的重力梯度仪,其观测值用于恢复高精度高分辨率的地球重力场。本文利用EIGEN-5C、EGM2008、GOTIM3、GGM03S高精度全球重力场模型,确定了GOCE引力梯度张量的对角分量观测值(Vxx、Vyy、Vzz)的校准参数,分析了比例因子的稳定性,并讨论了相同模型不同阶次、同阶次不同模型以及是否估计漂移参数对比例因子、偏差参数及校准观测值的影响。研究表明比例因子的稳定性在10-4的量级,利用250阶的EIGEN-5C模型和EGM2008模型校准得到观测值的差异小于10-4 E,远远小于观测误差,以1d为周期估计校准参数时,是否估计漂移对校准结果的影响达到0.4E。同时,校准前后观测值差异的频谱说明校准过程主要影响Vxx、Vyy、Vzz观测值的低频部分,即来自先验重力场模型的中低(150)阶次,考虑到GOCE引力梯度的观测频带,校准后的观测值可用于恢复中高频的重力场信号。  相似文献   

基于3S技术的国土资源综合调查方法研究——以黑龙江省为例     

初禹  丁宇雪 《测绘工程》2015,(7)

遥感信息具有宏观性、综合性、周期性、详细性、客观性和时空变化多层性,正在逐渐成为国土资源调查与监测的基本信息源。现阶段,我国的遥感卫星事业发展迅猛,我国的国产卫星资源三号、资源一号02C以及高分一号、二号卫星数据已经投入到各个领域的应用中,同时遥感信息提取水平也逐渐提高。这不仅拓宽了遥感技术的应用广度,而且使其在原有领域的应用得以深化、细化,向更深层次发展,并满足国土资源综合调查需要。  相似文献