共查询到19条相似文献,搜索用时 812 毫秒
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在简要介绍星载海洋雷达高度计的准最佳最大似然估计系统工作原理的基础上,根据星载海洋雷达高度计跟踪控制的要求,设计了星载海洋雷达高度计的准最佳最大似然估计系统。该系统将高度跟踪和AGC(自动增益控制)、斜率跟踪有机地结合起来,可对星载海洋雷达高度计的工作实行有效的控制,获得各项参数的较高测量精度。 相似文献
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阎敬文 《吉林大学学报(信息科学版)》1995,(3)
为提高雷达系统测量精度及分辨力,在研制海洋雷达高度计中采用了全去斜坡技术。在分析了全去斜坡技术原理的基础上,进行了较详尽的数学推导。该技术采用频率变换方法,能获得用脉冲压缩方法无法达到的压缩效果,从而提高测量精度和分辨力。应用实践表明,该技术可使脉冲压缩比提高到1000倍,分辨力达到5cm,大大提高了高度计的测量精度。 相似文献
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为了提高双频雷达高度计降雨情况下风速反演精度,确立合理的标准关系.采用Jason-1的7年半统计资料,通过多项式拟合的方法导出了新的标准关系.统计结果表明,该标准关系精度明显高于Quartly与Yang所建立的标准关系精度.该关系式为今后的双频雷达高度计的降雨反演提供了新的理论依据.在统计回归过程中,亦发现该标准关系可... 相似文献
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河流是人类重要的用水来源,同时也是地球水循环的重要组成部分.目前的河流监测方法大多采用水文站监测方式,但在恶劣环境下监测仪器易损坏,导致水文站测量数据的缺失.雷达技术具有全天时、全天候对地观测能力,不易受到环境干扰.本系统基于雷达高度计和SAR(Synthetic Aperture Radar)遥感技术,实现了河流宽度、水位及径流等参数的计算功能.本系统的推广应用能够为河流径流监测工作提供更好的技术支撑. 相似文献
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《科技导报(北京)》2010,(15)
<正>"嫦娥"1号所用激光高度计设计原理发布"嫦娥"1号(CE-1)卫星激光高度计2007年10月24随CE-1卫星发射升空,11月28日在环月轨道上开机后,获取了共计912万点有效月球三维高层数据,圆满完成探测任务。 相似文献
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对雷达产品在研制阶段的可靠性设计进行审查和控制,以保证雷达产品可靠性设计技术及各项措施得到贯彻和落实,确保研制生产过程的质量与可靠性。 相似文献
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给出了星载雷达高度计OCOG跟踪算法的使用步骤 ,明确指出该算法的特点是不仅考虑回波前沿部分 ,还考虑偏离天底点较远位置的回波拖尾部分 .通过与常规跟踪算法WSG进行仿真比较 ,显示了该算法产生的距离误差信号具有更宽泛的线性范围 ,能够保证回波前沿锁定在观测窗内 ,得到的等效信噪比更大 ,而均方根误差又能小得多 ,是一种鲁棒性良好的跟踪算法 . 相似文献
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介绍了基于DES-3型局用数字程控交换机七号信令系统的总体方案及硬件实现。该系统已通过同种机型间的有效性测试以及与S1240、E10B等异种机的兼容性测试。各项指标均已达到邮电部的测试规范要求。 相似文献
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提高雷达高度表测高精度的方法研究 总被引:1,自引:0,他引:1
讨论了雷达高度表脉冲回波受地形、地貌、植被及雷达本身参数(波束、发射功率、频率、天线及指向误差角ξ)影响的问题,给出了一种在飞行实验中运用高速A/D直接测量雷达高度表回波波形数据,通过对飞行试验数据积累、分析、处理及计算机仿真,获得了高度表测高修正模型的方法. 相似文献
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Improved retracking algorithm for oceanic altimeter waveforms 总被引:1,自引:0,他引:1
Over the deep oceans without land/ice interference, the waveforms created by the return altimeter pulse generally follow the ocean model of Brown, and the corresponding range can be properly determined using the result from an onboard tracker. In the case of complex altimeter waveforms corrupted due to variety of reasons, the processor on the satellite cannot properly determine the center of the leading edge, and range observations can be in error. As an efficacious method to improve the precision of those altimeter observations with complex waveforms, waveform retracking is required to reprocess the original returning pulse. Based on basic altimeter theory and the geometric feature of altimeter waveforms, we developed a new altimeter waveform retracker, which is valid for all altimeter waveforms once there a reasonable returning signal exists. The performances of the existing Beta-5 retracker, threshold retracker, improved threshold retracker, and the new retracker are assessed in the experimental regions (China Seas and its adjacent regions), and the improvements in the accuracy of sea surface height are investigated by the difference between retracked altimeter observations and referenced geoid. The comparisons denote that the new algorithm gives a best performance both in the open ocean and coastal regions. Also, the new retracker presents a uniform performance in the whole test region. Besides, there is a significant improvement in the short-wavelength precision and the spatial resolution of sea surface height after retracking process. 相似文献
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The joint US/French Jason-1 satellite altimeter mission, launched from the Vandenberg Air Force Base on December 7, 2001, continues the time series of centimeter-level ocean topography observations as the follow-on to the highly successful T/P radar altimeter satellite. Orbit error especially the radial orbit error is a major component in the overall budget of all altimeter satellite missions, in order to continue the T/P standard of observations. Jason-1 has a radial orbit error budget requirement of 2.5 cm. In this work, two cycles (December 19, 2002 to January 7, 2003) of the Jason-1 on-board GPS data were processed using the zero-difference (ZD) dynamic precise orbit determination (POD) technique. The resulting Jason-1 orbit accuracy was assessed by comparison with the precise orbit ephemeris (POE) produced by JPL, orbit overlaps and SLR residuals. These evaluations indicate that the RMS radial accuracy is in the range of 1-2 cm. 相似文献
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With the successful launch and official commissioning of China’s first dynamic ocean environment satellite Haiyang-2(HY-2),China’s capabilities for oceanic environment monitoring and oceanic resource detecting have been further improved and enhanced.Precise tracking and orbit determination are not only key technical concerns in the ocean dynamic environment satellite project but also necessary conditions for carrying out related oceanic science research using observational data obtained using spaceborne instruments including radar altimeter.In this study,the current available status of international satellite laser ranging(SLR) monitoring on HY-2 was introduced.Six-months of SLR data from HY-2 were processed to obtain precise satellite orbit information using the dynamic orbit determination method.We carried out a detailed assessment of the SLR orbit accuracy by internal evaluation,comparisons with the orbit derived by the French Doppler orbitography and radio-positioning integrated by satellite(DORIS) system,and station-satellite distance validation.These assessments indicate that the three-dimensional orbital accuracy of HY-2 is about 12.5 cm,and the radial accuracy is better than 3 cm.It provides a good example of the application of international SLR monitoring and precise orbit determination in China’s earth observation satellite project. 相似文献
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为了提高S波段微波多普勒雷达系统的控制精度与接收性能,同时将控制与接收融合到一起,基于数字信号处理和可编程逻辑门阵列(DSP+FPGA)设计了S波段系统雷达主板,其作为雷达系统中的控制与接收中心,可以根据上位机命令产生精准的时序控制信号,同时对中频回波信号进行采样、下变频、存储和上传等。通过后期性能测试,雷达主板产生的时序控制信号精准,接收性能良好,灵敏度达-94 dBm,无杂散动态范围达50 dB,闭环测试下,在输入中频回波信号幅度为-17 dB时,多普勒谱信噪比达70 dB,因此设计的雷达主板完全满足S波段多普勒雷达系统的要求。 相似文献
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利用卫星测高重力异常,基于非补偿板块模型,反演了南海海域海底地形.考虑向下延拓容易导致的高频分量剧烈震荡,引入统计学中的统计相关理论,采用线性回归模型,对得到的海深模型进行了新的计算,反演结果与LDEO船测深数据相比较,两者之差的RMS为253.3m,较ETOPO5海深模型精度和分辨率均有明显的提高. 相似文献
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介绍了WIN2000下基于VC++的雷达图像采集压缩记录系统的组成,主要阐述雷达图像采集压缩记录系统配置文件的手动设置方法和设置配置文件时需要注意的问题,应用此方法能够快速配置系统的配置文件,使雷达图像采集卡采集的图像质量达到最佳.同时介绍了雷达图像的采集、压缩、存储、传输模块程序设计.此设计能使系统稳定可靠运行. 相似文献