一种基于CCD的白天激光光束的监视方法     

WANG Bin  ZHANG Zhongping YANG Fumin CHEN Juping 《中国科学院上海天文台年刊》2004,(1)

介绍了采用曝光时间小于 10的高速CCD以及相应的图像卡成功实现白天强背景光下实时显示激光束的方法 ,该方法可以有效提高卫星激光测距的白天测距能力。  相似文献   

抗差方差分量估计在卫星定轨中的应用   总被引：5，自引：2，他引：3  

秦显平  杨元喜 《大地测量与地球动力学》2003,23(4):40-43

针对卫星精密定轨过程中观测资料存在粗差以及观测资料的合理定权问题，将抗差方差分量估计引入到卫星精密定轨中。采用Lageos 2卫星1996年1月至2000年12月的全球SLR实测数据进行了卫星精密定轨计算，结果表明，抗差方差分量估计既可以有效地减弱观测资料中粗差的影响，又可以较好地解决观测资料的合理加权问题，从而可以提高卫星的定轨精度。  相似文献   

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祝芙英  吴云  杜瑞林  张念 《大地测量与地球动力学》2008,28(2):127-131

????????SLR??2005??????3????????LAGEOS-1??BeaconC??Jason1????????ι?????????LAGEOS??1??????о?????????????????????????????????????????????????????ó?????SLR??3??????????????????2 cm??  相似文献   

加速仪数据在CHAMP卫星精密定轨中的贡献   总被引：3，自引：1，他引：2  

蔡五三  郑作亚  冯初刚  朱元兰 《天文学报》2005,46(1):46-54

通过用几个实例计算，评估了CHAMP卫星加速仪数据对SLR数据定轨精度的贡献．结果显示用加速仪数据代替非保守力对CHAMP卫星进行精密定轨时，其SLR的残差从原来的16．5cm减少到2．7cm，与精密轨道相比，卫星位置误差由18．9cm减少到6．2cm(一天资料)．  相似文献   

流动SLR北京站观测结果分析   总被引：6，自引：4，他引：2  

郭唐永  王谭强 《大地测量与地球动力学》2002,22(4):120-123

中国地震局地震研究所流动SLR观测站于2000年8－11月在北京房山卫星激光观测站作对比观测，获得了344圈资料，描述了观测情况，并展示了部分有结果。这是我国流动SLR取得的第一批观测结果，其数据已上Internet网，全球共享。  相似文献   

卫星激光反射器质心改正的概率模型     

赵群河  王小亚  何冰  张忠萍  陈婉珍  陈宏宇  蒋虎  胡小工 《测绘学报》2015,44(4):370-376

卫星激光测距通过测量激光脉冲在地面观测站和卫星之间的往返时间来计算卫星到测站的距离。激光反射器位置到卫星质心的距离即质心改正(CoM)需要精确标定,以提高卫星测距精度。卫星激光反射器的质心改正误差主要由角反射器分布效应引起,质心改正与激光束的入射角、角反射器排列结构和地面测距站位置有关。卫星角反射器对光子的反射概率与反射器的有效雷达截面积成正比,本文对角反射器的有效雷达截面面积进行拟合,建立以入射角为随机变量的概率模型,计算了球形LAGEOS-1/2的质心改正值,基于长期观测数据使用不同质心改正值进行了精密定轨,分析了其加权残差变化。同时,对BeiDou-M3的角反射器为平面阵列的情况进行了讨论,计算了质心改正值,用一个月的数据进行精密定轨。试验结果表明,基于概率理论的模型在精密轨道中与国际激光测距服务(ILRS)公布的结果相当,说明概率模型适用于球型卫星或非球型卫星。  相似文献   

不同观测技术的Jason-2卫星精密定轨评估     

盛传贞  甘卫军  赵春梅  孙保琪  梁诗明  陈为涛  肖根如 《测绘学报》2014,43(8):796-802

针对GPS、SLR和DORIS三种不同手段的各自定轨精度问题,本文基于不同的轨道评估方法进行了深入分析。以JASON-2卫星为例,分析了姿态模型误差及其对定轨精度的影响,分别讨论了GPS、SLR和DORIS的定轨策略和定轨精度,并基于轨道评估结果进行了轨道叠加。基于实测数据进行了试验,试验结果表明,JASON-2卫星姿态模型误差对DORIS、GPS和SLR轨道影响分别为0.040、0.036和0.033m;DORIS定轨结果优于GPS和SLR,SLR定轨精度最差;基于SLR验证和轨道重叠结果加权,对GPS、SLR和DORIS轨道进行轨道叠加,其精度一致,通过与JPL轨道比较,其径向精度为2cm。  相似文献   

资源三号02星双频GPS快速精密定轨     

吴琼宝  赵春梅  朱广彬  卫志斌 《大地测量与地球动力学》2018,38(1):73-77

采用资源三号02星双频GPS观测数据和CODE快速星历，利用非差简化动力学方法实现卫星精密定轨。通过卫星轨道重叠弧段检验，轨道径向精度优于3.90 cm，位置精度优于5.52 cm。利用SLR观测数据检核卫星轨道，精度优于4 cm。采用轨道外推和瞬时根数方法预报轨道，12 h内切向精度优于30 m。  相似文献   

Apparent dynamic stability of the southeast African coast despite sea level rise          下载免费PDF全文

Alan M Smith  Simon C Bundy  J Andrew G Cooper 《地球表面变化过程与地形》2016,41(11):1494-1503

The coast of southeast Africa is dominated by sandy beaches that tend to be confined within log‐spiral or headland‐bound embayments. Investigations using serendipitous air imagery data set have been previously undertaken and conclusions drawn about the stability of the coast. We show that conclusions drawn from this data, with respect to the high water mark (HWM) position are fraught with errors, which include tidal state, pressure regime, beach slope, high‐swell erosion, seasonal and multi‐annual changes. We highlight and discuss these sources of error, together with their magnitudes. The most significant of these are the high‐swell, seasonal and multi‐annual variations. From case studies we show that the seasonal beach rotation and long‐term beach width variation are responsible for tens of metres of unaccounted HWM variation, 30 to 50 m is common, with maximums reaching 60 to 100 m. Overall the southeast African coastline appears to be in a state of long‐term dynamic equilibrium. There is no evidence of any sea‐level rise‐forced transgression in the coastal sediment budget, despite sea‐level rise (SLR). If such a signal is, in fact present, it is lost within the beach width variation. Some southeast African coastal reaches are suffering chronic erosion, but these are related to anthropogenic impacts. The extreme difficulty of placing a HWM, with any temporal validity on this coast precludes the routine use of the Bruun Rule. Although no transgressive signature is found, there is evidence of a decreasing coastal sand budget as a result of anthropogenic or natural climate change, or both. This decrease in the coastal sand volume is likely to result in increased future erosion. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

A Tikhonov regularization method to estimate Earth's oblateness variations from global GPS observations     

《Journal of Geodynamics》2014

Earth's oblateness is varying due to the redistribution of Earth's fluid mass and the interaction of various components in the Earth system. Nowadays, continuous Global Positioning System (GPS) observations can estimate Earth's oblateness (J₂) variations with the least squares method, but are subject to ill-conditioned equations with limited GPS observations and aliasing errors from truncated degrees. In this paper, a Tikhonov regularization method is used to estimate J₂ variations from global continuous GPS observations. Results show that the J₂ has been better estimated from GPS observations based on a Tikhonov regularization method than the usual least squares method when compared to SLR solutions. Furthermore, the amplitudes and phases of the annual and semi-annual J₂ variations are closer to the SLR results with truncated degrees from 2 to 5. Higher truncated degrees will degrade the J₂ estimate. Annual J₂ variations are best estimated from GPS observations with truncated degree 4 and semi-annual J₂ variations are best estimated with truncated degree 2.  相似文献