共查询到20条相似文献，搜索用时 109 毫秒
1.
夏炯煜 《大地测量与地球动力学》1990,(3)
本文利用1983年9月—1984年10月国际地球自转主联测期间LAGEOS激光测距资料,解算了11个台站间的55条基线,基线的内部精度为±1.5cm;与其它作者和甚长基线干涉测量的几个欧洲和美洲台站间的基线的比较表明,一般的差异不到10cm,特别是本文结果与VLBI的值最大差为4cm,因此,估计外部精度为10cm左右。 相似文献
2.
推导引入新的归心基线的ITRF组合解算公式,分析陆态网络归心基线对ITRF2008中坐标及其速度的影响。结果表明,在ITRF2008中引入陆态网络中长春、昆明和乌鲁木齐3个并址站2011年观测得到的归心基线及其协方差阵的解算成果,与ITRF2008结果相比,绝大多数站点的坐标差值小于10 mm,坐标速度差值小于1 mm/a;绝大多数站点的水平速度场和垂直速度场与ITRF2008速度场保持一致。 相似文献
3.
介绍了2011年中国科学院新疆天文台南山站GPS和25m VLBI天线的归心测量方案、局域三角测量网、高程控制网与靶标交会测量方法及资料解算。利用测量数据,首次建立了南山GPS与VLBI空间大地测量技术并置站本地连接参数,测量精度优于1mm。 相似文献
4.
GPS监测地壳运动数据处理 总被引：6，自引：0，他引：6
介绍GAMIT软件的参数设置，以消除或减弱GPS的主要误差，获取高质量的基线处理结果。通过对GAMIT的基线解算结果H文件的处理，求解基线的重复率，平面上重复率不超过3mm，垂直方向不超过7mm，并对基线解算质量进行了评定。在研究全球板块运动或区域性地壳形变时，以GPS单天解的基线结果作为输入量，考虑各期计算结果之间的朴素联系，计算得到台站漂移量和漂移速度，从而得到地壳运动信息，对中国境内IGS站的算例分析表明，在ITRF2000框架下，计算出的漂移速度与IGS站提供的速度大小与方向基本一致。 相似文献
5.
为分析VLBI观测资料解算地球自转参数的精度,根据VLBI观测原理及其误差方程,分别利用2020年VLBI观测数据及CONT17连续加密观测的XA、XB两种频率通道数据解算地球自转参数,并以EOP14 C04序列作为计算外符合精度的参考序列。结果表明,VLBI观测数据解算地球自转参数各分量的外符合精度均能满足高精度要求,比较解算结果与同时段GPS连续数据的解算结果发现,两者精度总体处于同一水平;CONT17观测的XA、XB两种频率通道数据解算极移时精度相当,但前者在稳定性及解算UT1-UTC序列精度上具有较大优势。 相似文献
6.
推导了联合甚长基线干涉测量（VLBI）和天文导航的月球车定位计算公式,并利用嫦娥三号（CE-3）实测数据分别解算VLBI单独定位和联合天文导航定位的月球车定位结果。结果表明,联合定位相对于单独VLBI定位,提高了天文导航的定位精度,改善了月球车的定位精度;同时,联合VLBI和天文导航定位也保障了月球车定位的可靠性与稳定性。 相似文献
7.
针对我国自主研发的北斗全球卫星导航系统定位精度实际工程应用问题,提出了一种格网平均值方法快速获得厘米级的CGCS2000坐标.采用GAMIT10.71版本软件包解算北斗系统数据,测试北斗二号和北斗三号解算基线精度,结果显示北斗系统基线相对精度达到10-9级别.基于实际轨道交通首级控制网解算北斗系统数据结果表明,利用格网平均值法获取的速度场计算坐标转换可以达到厘米级别的精度,若能获取更准确的速度,完全可以实现ITRF2008到CGCS2000坐标厘米级别转换. 相似文献
8.
基于美国CORS网数据,分别选取平均基线长度和站间高差均不相同的6个GPS实验网,使用GAMIT/GLOBK软件,从基线较差、基线重复性、NRMS值以及解算中误差等方面分析站间高差对短时段（4 h）GPS基线解算的影响及削弱这些影响的方法。结果得出,当测站间高差大于100 m时,如果不估计对流层参数,即使是短基线也会使解算基线在高程方向的偏差达到1 cm,而对平面分量影响很小。此时,必须通过估计天顶方向的对流层参数来削弱其影响,才能保证最终解算的基线结果在高程方向的误差小于1 cm。 相似文献
9.
本文利用武汉人卫激光测距站与其它15个台站的1985年7—9月间的LAGEOS激光测距资料,用动力学方法首次解算出武汉站在全球人卫激光测距网中的地心坐标,各坐标分量的内部精度约为±3cm,外部精度约为±20cm. 相似文献
10.
利用长城站、中山站及周边13个IGS站2018年的观测数据,对比分析不同卫星截止高度角、对流层映射函数和全球海潮模型对GNSS坐标精度的影响。结果表明,截止高度角设为7°时,GNSS坐标解算精度最优,随着截止高度角的增大或减小,精度逐渐降低;采用VMF3模型解算的双差定位精度优于NMF、GMF和VMF1模型,VMF3模型解算的精密单点定位精度与GMF和VMF1模型相当;海潮负荷对GNSS坐标解算的影响与坐标方位有关,高程方向可达cm级,选用不同的海潮模型解算的GNSS坐标差异可忽略不计。 相似文献
11.
介绍“中国大陆构造环境监测网络”GNSS基准站观测数据的处理和分析.数据处理基于陆态网工程2010-07-01 -2012-03-16日的252个GNSS基准站观测数据,获得了基准站的坐标单日解时间序列,利用抗差最小二乘估计拟合出了这些站的速度场. 相似文献
12.
Climate change and its effects on runoff of Kaidu River,Xinjiang, China: A multiple time-scale analysis 总被引：6，自引：0，他引：6
This paper applied an integrated method combining grey relation analysis, wavelet analysis and statistical analysis to study climate change and its effects on runoff of the Kaidu River at multi-time scales. Maj or findings are as follows： 1） Climatic factors were ranked in the order of importance to annual runoff as average annual temperature, average temperature in autumn, average temperature in winter, annual precipitation, precipitation in flood season, av- erage temperature in summer, and average temperature in spring. The average annual temperature and annual precipitation were selected as the two representative factors that impact the annual runoff. 2） From the 32-year time scale, the annual runoff and the average annual temperature presented a significantly rising trend, whereas the annual precipitation showed little increase over the period of 1957-2002. By changing the time scale from 32-year to 4-year, we observed nonlinear trends with increasingly obvious oscillations for annual runoff, average annual temperature, and annual precipitation. 3） The changes of the runoff and the regional climate are closely related, indicating that the runoff change is the result of the regional climate changes. With time scales ranging from 32-year, 16-year, 8-year and to 4-year, there are highly significant linear correlations between the annual runoff and the average annual temperature and the annual precipitation. 相似文献
13.
对鲜水河断裂带区域重力网 10多年的观测资料进行了精细处理 ,在此基础上 ,构制出能展现异常变化特征的重力场空间分布图。分析认为 :鲜水河断裂带和龙门山断裂对网区重力的时间变化有明显的控制作用 ;区域重力变化的空间分布存在较大的差异 :东南段的变化大于西北段 ;尤其是康定一带 ,是现阶段地壳应力容易累积的危险地区。分析还表明 ,在巴塘、小金和丽江等地震前 ,重力场有明显的异常变化 相似文献
14.
Recently, study in past trends of climate variables gained significant consideration because of its contribution in adaptions and mitigation strategies for potential future changes in climate, primarily in the area of water resource management. Future interannual and inter-seasonal variations in maximum and minimum temperature may bring significant changes in hydrological systems and affect regional water resources. The present study has been performed to observe past(1970-2010) as well as future(2011-2100)spatial and temporal variability in temperature(maximum and minimum) over selected stations of Sutlej basin located in North-Western Himalayan region in India. The generation of future time series of temperature data at different stations is done using statistical downscaling technique. The nonparametric test methods, modified Mann-Kendall test and Cumulative Sum chart are used for detecting monotonic trend and sequential shift in time series of maximum and minimum temperature. Sen’s slope estimator test is used to detect the magnitude of change over a period of time on annual and seasonal basis. The cooling experienced in annual TMax and TMin at Kasol in past(1970-2010) would be replaced by warming in future as increasing trends are detected in TMax during 2020 s and 2050 s and in TMin during 2020 s, 2050 s and 2080 s under A1 B and A2 scenarios. Similar results of warming are also predicted at Sunnifor annual TMin in future under both scenarios which witnessed cooling during 1970-2010. The rise in TMin at Rampur is predicted to be continued in future as increasing trends are obtained under both the scenarios. Seasonal trend analysis reveals large variability in trends of TMax and TMin over these stations for the future periods. 相似文献
15.
利用时变重力场模型、GLDAS水文模型和湖泊水量变化数据反演三江源区域2003~2020年地下水储量变化,使用奇异谱分析方法对地下水变化时间序列进行分析。结果表明,2003~2012年三江源区域地下水储量整体呈现增长趋势,年增长率为0.7 cm/a;2013~2020年三江源区域地下水储量整体呈现减少趋势,年增长率为-0.3 cm/a;三江源区域地下水年度变化主要受降雨补给规律的影响,降雨对地下水的补给滞后期为2个月。 相似文献
16.
THE WET-DRY CHANGES IN RECENT 40YEARS IN TAKLIMAKAN AREA 总被引：6，自引：0，他引：6
IINTRODUCTIONAlongwiththePetroleumexploitationofTarimBasin,consideringaboutwaterresources,peoplepaidmuchattentiontothestudyofthemodernclimatechangeinTaklimakanarea.SomePeoplehaddonemanalySeSwiththemeteorologicaldatainthearea(Yang,1992;Jietal.,1992;Zheng,1991;Xue,1989;Li,1989;Wenetal.,1988).BasedontheO~ionaldstaofprecipitationinrecent40years,thisPaperCarefullyanalyZedthewet-drychangeinrecentseveraldeCadesinTaklilnakanareaanditsneighdringareas(thenorthernXinjiang,QinghaiandGansuPro… 相似文献
17.
针对雅安地区特殊的"天漏"气候特征及以往对其变化特征研究较少问题,利用雅安市1951~2010年降水资料,从降水量和雨日数出发,通过回归分析、小波分析等现代气候统计诊断方法,综合分析"雅安天漏"的变化特征。结果表明:在降水量上,雅安市年降水量总体呈显著减小趋势,20世纪90年代中期以后尤为明显;从季节尺度上来看,春、夏、秋三季降水量呈现明显减少趋势,但冬季与之相反;从逐月降水比重可以看出,极大值主要出现在7、8、9月;从量级上看,小雨、中雨、大雨的降水量均在减小,暴雨却在增加,但各量级降水所产生的降水量与全年总降水量的比值相对比较稳定。从雨日数上看,雅安市四季的雨日数均表现出减少趋势,各个强度量级的雨日数也均在波动减小。小波分析结果显示:年降水量和雨日数在年代际时间尺度均存在准周期振荡。 相似文献
18.
Trends in temperature and precipitation extremes over Circum-Bohai-Sea region, China 总被引：2，自引：0，他引：2
Trends in temperature and precipitation extremes from 1961 to 2008 have been investigated over Circum-Bohai-Sea region,China using daily temperature and precipitation data of 63 meteorological stations.The re-sults show that at most stations,there is a significant increase in the annual frequency of warm days and warm nights,as well as a significant decrease in the annual frequency of cold days,cold nights,frost days,and annual diurnal temperature range(DTR).Their regional averaged changes are 2.06 d/10yr,3.95 d/10yr,-1.88 d/10yr,-4.27 d/10yr,-4.21 d/10yr and-0.20℃/10yr,respectively.Seasonal changes display similar patterns to the annual results,but there is a large seasonal difference.A significant warming trend is detected at both annual and seasonal scales,which is more contributed by changes of indices defined by daily minimum temperature than those defined by daily maximum tem-perature.For precipitation indices,the regional annual extreme precipitation displays a weak decrease in terms of magnitude and frequency,i.e.extreme precipitation days(RD95p),intensity(RINTEN),proportion(RPROP) and maximum consecutive wet days(CWD),but a slight increase in the maximum consecutive dry days(CDD),which are consistent with changes of annual total precipitation(PRCPTOT).Seasonally,PRCPTOT and RD95p both exhibit an increase in spring and a decrease in other seasons with the largest decrease in summer,but generally not significant.In summary,this study shows a pronounced warming tendency at the less rainy period over Circum-Bohai-Sea region,which may affect regional economic development and ecological protection to some extent. 相似文献
19.
对华北地区定点台站形变观测资料,采用傅立叶去年周期和线性拟合的方法进行处理.结果表明,华北地区现阶段的变化未形成主体异常时段,反映出断层未进入强烈活动阶段;首都圈地区跨断层资料异常数量不多,没有形成同步异常,异常变化幅值也不是很大,中短临地震异常不明显. 相似文献