基于多无人机协作的无源目标定位是无人机在军事侦察等领域应用的关键技术.现有研究大部分针对单目标的无源定位,本文研究利用到达时间差观测对多目标进行无源定位的高效算法.将已有的两步加权最小二乘方法中辅助变量与目标位置的非线...基于多无人机协作的无源目标定位是无人机在军事侦察等领域应用的关键技术.现有研究大部分针对单目标的无源定位,本文研究利用到达时间差观测对多目标进行无源定位的高效算法.将已有的两步加权最小二乘方法中辅助变量与目标位置的非线性关系作为约束,建立约束加权最小二乘多目标定位模型,并化简为含多个二次不定等式约束的二次规划问题.这是一个NP-hard的非凸优化问题.本文提出一种CWLS (constrained weighted least squares)近似迭代算法,在迭代过程中用线性等式约束近似二次不定等式约束,使其近似优化问题有解析解.理论分析表明,该算法收敛的极限一定是原问题的全局最优解. Monte Carlo实验表明,该算法在绝大部分情况下能快速收敛,且对多目标定位的精度优于两步加权最小二乘方法.展开更多
We demonstrate coherent optical frequency dissemination over a distance of 972 km by cascading two spans where the phase noise is passively compensated for.Instead of employing a phase discriminator and a phase lockin...We demonstrate coherent optical frequency dissemination over a distance of 972 km by cascading two spans where the phase noise is passively compensated for.Instead of employing a phase discriminator and a phase locking loop in the conventional active phase control scheme,the passive phase noise cancellation is realized by feeding double-trip beat-note frequency to the driver of the acoustic optical modulator at the local site.This passive scheme exhibits fine robustness and reliability,making it suitable for long-distance and noisy fiber links.An optical regeneration station is used in the link for signal amplification and cascaded transmission.The phase noise cancellation and transfer instability of the 972-km link is investigated,and transfer instability of 1.1×10^(-19)at 10^(4)s is achieved.This work provides a promising method for realizing optical frequency distribution over thousands of kilometers by using fiber links.展开更多
文摘基于多无人机协作的无源目标定位是无人机在军事侦察等领域应用的关键技术.现有研究大部分针对单目标的无源定位,本文研究利用到达时间差观测对多目标进行无源定位的高效算法.将已有的两步加权最小二乘方法中辅助变量与目标位置的非线性关系作为约束,建立约束加权最小二乘多目标定位模型,并化简为含多个二次不定等式约束的二次规划问题.这是一个NP-hard的非凸优化问题.本文提出一种CWLS (constrained weighted least squares)近似迭代算法,在迭代过程中用线性等式约束近似二次不定等式约束,使其近似优化问题有解析解.理论分析表明,该算法收敛的极限一定是原问题的全局最优解. Monte Carlo实验表明,该算法在绝大部分情况下能快速收敛,且对多目标定位的精度优于两步加权最小二乘方法.
基金the National Key Research and Development Program of China(No.2020YFC1909700)the National Natural Science Foundation of China(Nos.51974207,51774215).
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12103059,12033007,12303077,and 12303076)the Fund from the Xi’an Science and Technology Bureau,China(Grant No.E019XK1S04)the Fund from the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.1188000XGJ).
文摘We demonstrate coherent optical frequency dissemination over a distance of 972 km by cascading two spans where the phase noise is passively compensated for.Instead of employing a phase discriminator and a phase locking loop in the conventional active phase control scheme,the passive phase noise cancellation is realized by feeding double-trip beat-note frequency to the driver of the acoustic optical modulator at the local site.This passive scheme exhibits fine robustness and reliability,making it suitable for long-distance and noisy fiber links.An optical regeneration station is used in the link for signal amplification and cascaded transmission.The phase noise cancellation and transfer instability of the 972-km link is investigated,and transfer instability of 1.1×10^(-19)at 10^(4)s is achieved.This work provides a promising method for realizing optical frequency distribution over thousands of kilometers by using fiber links.
