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9月,举世瞩目的夏季达沃斯论坛在天津滨海新区召开。其间,中新天津生态城正式开工建设,作为献给论坛的一份厚礼,以全新的建设理念诠释未来城市发展之路。 相似文献
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三点定位法是被动测距的经典方法,但在短基线阵条件下,实际测量的结果往往不理想。为了分析各种误差对测距的影响并提高测距精度,通过理论分析和计算机仿真研究了相同假设条件下基阵孔径、目标方位、安装误差和平台摇摆对三点法测距精度的影响,并讨论了后两者产生误差的补偿和修正方法。研究结果表明:在时延估计精度不变时,基阵的有效孔径与测距精度成反比的关系;欲将30°≤θ≤150°扇面测距误差控制在10%以下,要求时延测量精度控制在微秒量级;中心阵元安装误差对不同方向目标测距精度的影响亦不相同。误差的补偿和修正方法能提高三点法被动定位的测距精度。 相似文献
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Analyzed the relation between time delay difference and time delay estimation errors, based on the principles of three-point locating, a reformed threshold method for time delay difference estimation of impulse signals, called as amendment estimation for short, is developed by introducing channel equalization technique to its conventional version, named as direct estimation in this paper, to improve the estimation stability. After inherent relationship between time delay and phase shift of signals is analyzed, an integer period error compensation method utilized the diversities of both contribution share and contribution mode of concerned estimates is proposed under the condition of high precision phase lag estimation. Finally, a cooperative multi-threshold estimation method composed of amendment and direct estimations to process impulse signals with three thresholds is established. In sea trials data tests of passive locating, this method improves the estimation precision of time delay difference efficiently. The experiments verify the theoretical predictions. 相似文献
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